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• U-Pb CA-ID-TIMS dates of zircon from plumbing system of a Permian caldera. • Distribution of ages interpreted through a new zircon saturation model. • Relative decrease of zircon mass with time implies monotonic cooling. • Late peak in zircon crystallization indicates episodic increase in heat supply. • Evidence for open-system processes preserved in zircon record of super-eruptions. The emplacement history and thermal evolution of subvolcanic magma reservoirs determine their longevity, size, and ability to feed volcanic eruptions. As zircon saturation is dependent on melt temperature and composition, quantitative analysis of zircon age distributions provides insight into the timing and magnitude of intensive parameter variations during the lifetime of a magma reservoir. Here we present chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) U-Pb zircon crystallization ages and in-situ zircon trace-element geochemistry for a suite of caldera-related, coeval plutonic and volcanic units of the Permian Sesia Magmatic System (northern Italy). This dataset documents the protracted growth and evolution (∼1 Myr) of a voluminous (>1000 km3), upper crustal (3.5–2.0 kbar) silicic magma reservoir. Systematic changes in zircon composition with time reveal episodic intrusions of new magma into a single, progressively differentiating reservoir which was dominantly kept at high crystallinity conditions (>60 vol.%). The volcanic and plutonic units both show dispersed and heterogeneous CA-ID-TIMS age distributions. A stochastic, thermodynamics-based zircon saturation model accounting for fractional crystallization, recharge and thermal rejuvenation effects on zircon growth and stability in a rhyolitic magma body reproduces the observed distributions of zircon U-Pb ages. Model results suggest that zircon compositional variability and crystallization age heterogeneity, characteristic of the Sesia and other large silicic systems, distinguish open- and closed-system magmatic processes. Specifically, an increase of the mass of crystallized zircons over time is the hallmark of thermally and chemically mature magma reservoirs, capable of producing voluminous eruptions upon changes in the thermal and mechanical state of the system. Conversely, a decrease in crystallized zircon mass over time characterizes systems where crystallization dominates over magma mobility, hindering substantial mass release during eruptive events. We suggest that quantitative analyses of dispersed zircon crystallization age distributions obtained with high-precision techniques can be applied to the plutonic and volcanic record to identify mature silicic magma reservoirs whose properties and storage conditions allowed for catastrophic caldera-forming eruptions. This work provides the petrologic community with a new tool to investigate the genesis and evolution of zircon-bearing intermediate to silicic intrusive magmatism and caldera-forming volcanism through time and across tectonic settings. [ABSTRACT FROM AUTHOR]

Source-to-sink evolution of a basin is a key to understand sedimentary processes, especially in a complex regional orogenic setting. Detrital zircon populations can be traced from their primary sources to their depositional settings. The resulting interpretations are enhanced by calculation of the adjacent orogen's paleoaltimetry, which provides additional insights into paleogeography. In this study, we present a combined methodology which aims to reconstruct source-to-sink evolution by the analysis of detrital zircon age distribution in sandstones, together with the calculation of paleo-elevation of surrounding orogens based on the chemical compositions of coeval magmatic rocks. We test the method using detrital zircon U–Pb geochronological data sets from the Triassic Songpan–Ganzi basin in central China, combined with whole-rock geochemical data from intermediate-composition magmatic rocks in adjacent crustal blocks. Application of the combined methodology supports a syn-collisional basin model for the formation of the Triassic Songpan-Ganzi basin in preference to a continental back-arc basin. The clastic sediments, mainly deep-marine turbidites, accumulated in a remnant Paleotethyan Ocean that was surrounded by the converging North China Block, South China Block, East Kunlun Orogenic Belt and the Qiangtang Block. The North China Block and the North Qaidam Block were major proto-sources of detrital zircons to the basin, contributing on average 12 % and 15 %, respectively. Triassic magmatic rocks in the East Kunlun and Qiangtang regions were major sources of igneous zircons, up to 68 % for the former and up to 56 % for the latter. Despite being located at a calculated elevation of ca. 4000 m, the Qinling Orogenic Belt contributed only ca. <10 % of the zircons, mostly restricted to the eastern depocenter of the basin. In contrast, supply from the North Qiangtang Block, despite its calculated lower elevation (1000–3000 m), accounts for 2–10 % of the detrital zircons in the basin, suggesting high erosion rates of this block. The minimal supply of zircons from the South China Block, restricted to 3–6 % in the central and western depocenters, is inconsistent with the zircon abundances predicted in the alternative back-arc basin model of the Songpan–Ganzi basin. [Display omitted] • A combined method is proposed to help reconstruct source-to-sink sediment transport. • Source proportions are tested using simulations of detrital zircon age populations. • Paleo-elevation calculations of adjacent blocks shed light on sediment provenance. • The method leads to a new interpretation of sediment sources, supply and deposition. [ABSTRACT FROM AUTHOR]

[Display omitted] • Summarized how big data can be applied in Precambrian research. • Conjoint analyses using big geochemical data reveal NCC formation and evolution. • Revealing magma cycle indicates NCC involved supercontinent cycle since Archean. • ML-based crust thickness reconstruction highlights arc subduction in NCC formation. • Spatio-temporal analyses suggest prolonged accretion in Precambrian NCC development. The enigmatic nature of the Precambrian era poses ongoing challenges for researchers seeking to uncover its secrets. With the exponential growth of scientific data, there exists a vast repository of information through which these mysteries can be explored. However, this data is often derived from fragmented investigations of geological phenomena within specific disciplinary domains and limited spatiotemporal boundaries, resulting in untapped potential for extracting undiscovered knowledge. To address this limitation, the field of big data science provides a foundation for multidisciplinary research on the geological evolution of the Precambrian. By harnessing the power of large-scale data integration and analysis, valuable insights into this pivotal era in Earth's history can be revealed. This paper offers a comprehensive overview of big data types in geoscience and elucidates common analysis methods. Through a case study focused on the North China Craton (NCC), we demonstrate the application of conjoint analysis to a dataset comprising rock and mineral geochemistry data. Employing local singularity analysis and wavelet analysis on zircon age frequency and Hf isotopic time series, we reveal a persistent long-term periodicity of 800–500 million years since 3.5 billion years ago. This finding indicates a co-evolution between the NCC and the global supercontinent cycle dating back to the Archean period. To investigate the formation of the NCC, we employ machine learning-based crustal thickness evolution reconstruction, which highlights arc formation during subduction as the primary factor, with regional mantle activities playing a secondary role in the convergence. Combining spatio-temporal evolution analysis of magmatic intensity and εHf(t) values, we infer that the development of the NCC primarily resulted from a prolonged process of accretion targeting the Eastern Block (the primary continent nuclei) through the incorporation of diverse arc massifs. This examination of the NCC serves as an example of how data collection, processing, and utilization can enhance our understanding of formational and evolutionary processes, signaling a paradigm shift in Precambrian research driven by the integration of big data. [ABSTRACT FROM AUTHOR]

The recognition and evaluation of polycyclic processes in sedimentary units are critical for proper provenance analysis and sedimentary system interpretation. The chemical composition and textural maturity of detrital tourmalines and zircons allow identification of sediment source areas, transport, and deposition. This study investigates the origin and history of post-Gondwanan sediments of the Tupanciretã Formation in southern Brazil, which lacks provenance studies. The Tupanciretã Formation is in a similar setting of the Bauru Supersequence at the uppermost portion of the Paraná Basin. Detrital zircon ages indicate sediment provenance from the Transamazonian, Grenvillian, and Brasiliano orogenic cycles of the Rio Grande do Sul Shield and younger grains (280-128 Ma) record contribution from the Choiyoi and Serra Geral igneous events, with a maximum deposition age of 127 Ma. Detrital tourmaline chemical analyses points to the Sul-riograndense Shield as the ultimate source, with metapelitic, metapsamitic and granitic origins. The predominant degrees of roundness are well rounded to rounded suggest evidence of sediment recycling from sedimentary units of the Paraná Basin, with important aeolian reworking involved. Zircon U–Pb signatures are compatible with the eastern sector of the Botucatu Formation in Rio Grande do Sul as the immediate source and the northeastern Sul-riograndense Shield as the ultimate source. Intermediate sources between the Sul-riograndense Shield and the Tupanciretã Formation were Gondwanan sedimentary units of the Paraná Basin, with possible participation from the Camaquã Basin. • The grains indicate important recycling of sediments with multiple sources, With important analysis of detrital zircons. • Detrital tourmalines indicate the participation of multiple basement rocks as the ultimate source. • There was an ancient drainage percolating from SSE to NNW, carrying polycyclic sedimentary rock material. • The high degrees of grain roundness indicate polycyclic sedimentary events, with a maximum deposition age of 127 Ma. [ABSTRACT FROM AUTHOR]

The Guanchín Formation is a sedimentary unit that was deposited during the Andean orogeny and is preserved in the Fiambalá Basin in NW Argentina. It records an advanced stage of the broken-foreland evolution in a transitional zone between the morphotectonic domains of the Precordillera, the Sistema de Famatina, the Western Sierras Pampeanas, and the southern Puna. Furthermore, it preserves a record of Late Miocene explosive volcanism that is common in all the foreland basins in this Andean segment. The Guanchín Formation was studied at Cuesta Loro Huasi and Guanchíncito sections, where seven facies associations (FA) were recognized. These represent ephemeral sandy braided fluvial systems with thin mud floodplains (FA1), sheetflow-dominated sandy-tuffaceous alluvial plain (FA2), perennial sandy braided fluvial system (FA3), fine-grained alluvial plain built up by unconfined flows and less terminal splays (FA4), sheetflow-dominated sandy alluvial plain (FA5), and sandy-gravelly (FA6) and sandy-dominated (FA7) braided fluvial system, arranged in chronological order from oldest to youngest. To date the formation, zircon U/Pb ages from tephras were obtained from the Cuesta Loro Huasi section, which yielded depositional ages of 6.10 ± 0.07, 5.89 ± 0.09, 5.60 ± 0.06, and 5.20 ± 0.05 Ma, while a fifth sample from the Guanchíncito section yielded an age of 3.26 ± 0.05 Ma. Additionally, detrital zircon analyses were performed to infer sediment provenance and constrain the maximum depositional age of sedimentary units. These data combined with paleoenvironmental analysis and clast compositions in conglomerates suggest that the Western Sierras Pampeanas had been uplifted around ∼6 Ma. By this time the drainage was dissipated as a distributary fluvial system (DFS) under semiarid climatic conditions, which received sediments from northern, eastern, and to a lesser extent from western sources. Around ∼3 Ma the basin started to receive coarse-grained sediments of braided fluvial systems (FA6 and 7) indicating a closer proximity to the Pampean sources areas. The Guanchín Formation records an overall progradational trend manifested through two minor progradational cycles, each one controlled by changes in the equilibrium profile and accommodation space of the basin. This trend is likely associated with a basinward increase in the subsidence rate or enhanced water availability in the headwaters, potentially linked to tectonic uplift in the eastern and/or northern ranges, including the final uplift of the southern Puna. Since previous works placed the deposition of the overlying Rodado de la Puna Formation deposition began at 4 Ma, these news ages suggest the top of the Guanchin Formation is younger than previously thought. • Guanchín Formation deposition began around 6.24 ± 0.38 Ma, extending to 2.69 ± 0.38 Ma. • It was deposited as a distributary fluvial system with multiple progradational pulses. • Sediment source was mainly from North and East, where Sierras Pampeanas outcrops. • Pampean sources prevail in Guanchín Formation's upper member. • Sierras Pampeanas uplift fully partitioned the Fiambalá Basin. [ABSTRACT FROM AUTHOR]

The northern Sichuan Basin of central China is an important region for investigating the continent-continent convergence that resulted from the closure of the Palaeo-Tethys Ocean. The Early-Middle Jurassic sediments of this basin record the palaeogeography, palaeoenvironments and tectonic evolution of the southern Qinling orogenic belt, especially the Dabashan thrust belt. Detailed sedimentological investigations, coupled with provenance analyses using zircon U Pb geochronology, demonstrate that during Early Jurassic times, conglomerate megafan facies extended across the northern Sichuan Basin into the Micangshan area deformed by South Dabashan thrusting and reached even as far as the Mianlue suture belt. These megafan deposits were mainly reworked from the Silurian sediments of the North Dabashan thrust belt (also called the South Qinling orogenic belt), north of the Mianlue suture. These conglomerates record the initial thrust-driven uplift and exhumation of the Qinling orogenic belt that rapidly followed the diachronous closure of the Mianlue oceanic basin. Moreover, our results show that the detrital materials of meandering stream, lacustrine and braided river delta facies that accumulated in the Middle Jurassic mainly originated from the southern Qinling orogenic belt, Mianlue suture zone and northern South China block, suggesting the southward progradation of the Dabashan fold-thrust belt onto the northern Yangtze block and the southward migration of the basin centre. These findings support a model in which the Early to Middle Jurassic evolution of the northern Sichuan Basin may have been triggered by East Asian convergence. [Display omitted] • The megafan oligomict conglomerate of the Baitianba Formation extended across the northern Sichuan Basin into the Micangshan area during the Early Jurassic. • The megafan oligomict conglomerates of the Baitianba Formation record the initial thrust-driven uplift and exhumation of the Qinling orogenic belt. • The Early-Middle Jurassic evolution of the northern Sichuan Basin may have been triggered by East Asian convergence. [ABSTRACT FROM AUTHOR]

• In the Ontario gneiss belt, Nd isotope boundaries can be identified in the field. • These isotope boundaries provide the best constraint on major crustal structures. • Spatial control from Nd isotope mapping complements age control from U-Pb dating. • Detrital zircon Hf model ages rather than U-Pb ages yield crustal extraction ages. With the increasing availability of U-Pb-Hf isotope analysis of zircon suites, does whole-rock Nd isotope analysis still have a role to play in mapping Precambrian gneiss terranes? I answer this question by examining the Ontario Gneiss Belt of the Grenville Province, and show that Nd isotope mapping still has a vital role to play in studies of Precambrian crustal evolution. Although U-Pb-Hf isotope analysis of detrital zircons can provide large suites of crystallization ages and epsilon Hf values, the poor spatial control of these data means that precise geographical control of crustal structure from Nd isotope mapping is still important. I demonstrate this for several regions of the Ontario Gneiss Belt, including northern Algonquin Park, western Lake Nipissing and Georgian Bay. In all these regions, mapping complex geographical patterns of crustal formation ages allows detailed documentation of large-scale crustal structure. Only with such an accurate understanding of crustal structure can accurate models of tectonic evolution be constructed in a complex, deeply exhumed orogenic belt such as the Grenville Province. [ABSTRACT FROM AUTHOR]

The Neogene Barreiras Formation is composed of continental to shallow marine sedimentary rocks that fringe the Brazilian Atlantic coast. Due to the large outcropping extent, various open questions about the evolution of this unit are still under debate. We present new U–Pb detrital zircon age spectra of four samples from the southern Espírito Santo state (Marataízes section) and two samples from the southern Bahia state (Arraial section). In both of the studied outcrops, a basal succession composed of coarse-grained cross-bedded sandstone, conglomerate and arkose with mudstone and claystone intercalations is superposed by an upper succession composed of massive sandstone, conglomerate and wacke. The U–Pb detrital zircon age spectra of all samples are dominated by Cambrian and Neoproterozoic grains. However, while the lower portion of both sections is dominated by Ediacaran-Cambrian grains, their upper portions also present significant Cryogenian-Tonian and sparse Paleoproterozoic (mainly Rhyacian and Statherian) and Neoarchean grains. This marks an important provenance shift within the Barreiras Formation, with a simple, local provenance sourced from the G1 to G5 granite supersuites of the Brasiliano Araçuaí Orogen for the basal layers contrasting with exposure of older basement rocks and Neoproterozoic anorogenic suites during deposition of the superior layers. We interpret the lower coarse sandstone and arkose-rich succession as deposited in an alluvial setting, with mud/claystones related to local flooding plains. Tectonic movements related to the evolution of the Atlantic passive margin, as described in previous works, caused a renewed uplift of the basement areas, exposing and denuding older rocks. Then, the upper layers deposited through debris flows covering the first succession. Further geochronological data is needed to test if the erosional event responsible for exposure of older basement rocks and sourcing of the upper layers would correspond to the Tortonian Sea level fall, related to growth of the Antarctic ice sheet to its present size. In this case, deposition of the lower succession would have occurred during the early Miocene, and the upper succession during the Pliocene. Our results shed light in the complex evolution of the sedimentary rocks generally grouped under the Barreiras Formation, and suggest important tectonic and climatic shifts during the Neogene evolution of the Brazilian Atlantic coast. • Detrital zircon U–Pb analysis of two sections of the Barreiras Formation • Source areas dominated by late Neoprotezoic to Cambrian sources (G1-G5 plutons) • Archean-Paleoproterozoic basement exposed in the source areas upsection • Tectonic, climatic and sea-level changes were possible provenance shift drivers • Complex evolution of the sedimentary rocks of the Barreiras Formation [ABSTRACT FROM AUTHOR]

The fluid-fluxed melting of igneous protoliths provides an opportunity to assess the role of fluid for the formation and modification of continental crust during high-temperature metamorphism. In order to investigate such an anatexis in the Buncheon granitic gneiss, Yeongnam Massif, we combined field, microstructural, and geochemical studies with the U-Pb and oxygen isotopic analyses of zircon and monazite. The granitic gneisses comprise metatexitic migmatites containing leucosomes, although neither melanosomes nor peritectic phases are associated with neosomes. These migmatites underwent syn -kinematic wet melting in the presence of ca. 0.9–1.4 wt% H 2 O (estimated from the pseudosection modeling) via the reaction, plagioclase + K-feldspar + quartz + H 2 O = melt, that took place at ∼650–750 °C and 4–6 kbar. The leucosomes differ in the degree of Eu anomalies and have variable amounts of rare earth elements, Zr, Y, and Th. Such variations are attributed to the segregation and migration of melts as well as the entrainment of residual phases. Sensitive high-resolution ion microprobe (SHRIMP) U-Pb ages of zircon and monazite were determined from two granitic gneisses and three leucosomes together with an adjacent, undeformed Hongjesa granite. Zircon grains are oscillatory-zoned, except for homogeneous overgrowth rims rarely present in two leucosomes. Both zircon domains were dated at ca. 1.98–1.97 Ga and ca. 1.86 Ga, respectively, suggesting that igneous protoliths were partly recrystallized during the late Orosirian. Monazites from two gneiss samples contain submicroscopic polycrystalline inclusions of K-feldspar + quartz + apatite, reflecting the presence of former melts, and yielded a pooled 207Pb/206Pb age of 1859 ± 6 Ma (n = 30). In contrast, monazites from a leucosome are inclusion-free, and yielded the youngest age of 1840 ± 16 Ma (n = 6). This result is interpreted to represent the melt crystallization at ca. 1.84 Ga following the ca. 1.86 Ga anatexis. On the other hand, monazite from the Hongjesa granite, yielded a weighted mean 207Pb/206Pb age of 1878 ± 5 Ma (n = 11), most likely reflecting a prograde metamorphic growth. The δ18O values of ca. 1.98–1.97 Ga igneous zircon in granitic gneisses are 7.1–7.2 ‰, but those from the leucosome are reduced at 5.9–6.7 ‰. The latter is largely identical to 5.7–6.7 ‰ estimated from ca. 1.86 Ga domains of zircon in the leucosome and monazite in the granitic gneiss; in contrast, a slightly lower δ18O value of 5.46 ± 0.61 ‰ is recorded in the ca. 1.84 Ga monazite of leucosome. The relatively low δ18O values are most likely accounted for by an influx of fluid that has apparently triggered partial melting in the granitic gneiss, and the fluid itself is possibly linked to the crystallization of mafic magmas in an arc complex. Taken together, in contrast to the majority of zircons preserving the crystallization age of igneous protoliths, monazites are more susceptible to recrystallization during the fluid-present melting and permit us to decode a protracted (∼20 m.yr.) episode from partial melting to melt crystallization in the Yeongnam Massif. Such a longevity of melt-present system typifies the prolonged crustal reworking of Paleoproterozoic Korean arc situated at the eastern margin of the North China Craton. • Partial melting of granitic gneiss occurred due to an influx of external fluids. • The melting occurred at 1.86–1.84 Ga following protolith emplacement at 1.98 Ga. • The interaction with low δ18O fluids in association with the crystallization of mafic magmas. • The protracted melting typifies the crustal reworking of the Paleoproterozoic Korean arc. [ABSTRACT FROM AUTHOR]

The Southernmost Brasília Orogen surrounds the southern margins of the São Francisco Craton. It exposes a structural window with a WNW-ESE direction formed by the Archean-Paleoproterozoic basement reworked by the Campo do Meio Shear Belt. Using metamorphic modeling, geothermobarometry, and U Pb dating of zircon and monazite, this study established the pressure-temperature-time (P-T -t) evolution of the Colônia metapelite, one of the main units of the Campo do Meio Shear Belt. This revealed a clockwise path with metamorphic peak conditions at 706 ± 16 °C and 9.7 ± 0.7 kbar on a staurolite-kyanite-muscovite-garnet-biotite schist, with cooling at ∼600 °C and ∼ 6 kbar. Forward metamorphic modeling based on the whole-rock composition of this sample supports partial melting in the staurolite stability field, facilitated by water influx. Water-fluxed anatexis promoted dissolution of detrital zircon grains. These processes, occurring during prograde metamorphism, are influenced by temperature, crystal size-distribution, bulk-rock composition, and the permanence of the rock at the thermal peak. Analysis of the zircon overgrowth zones, which were linked to peak metamorphic conditions, produced an age of 605 ± 7 Ma. The monazite age of 580 ± 5 Ma was associated with later syntectonic melt crystallization. The clockwise P-T -t path of the Colônia metapelite is similar to the evolution of Neoproterozoic units from the Southernmost Brasília Orogen. However, the degree of dissolution in detrital zircon grains restricts accurate evaluation of the possible stratigraphic correlations proposed in the literature. • Staurolite stability can exceed the solidus curve in the fluid-saturated melt. • Kyanite stabilization can occur after melting into low-Al metapelites. • Water-fluxed melting promotes dissolution-recrystallization in detrital zircon. • Metamorphic ages overlap the ages of likely source areas. • Sedimentary geochronological approach for melting-bearing rocks may be unfeasible. [ABSTRACT FROM AUTHOR]

[Display omitted] • A rapid cooling/exhumation event occurred in the Changle-Nan'ao Belt during the period from 80 to 70 Ma. • The Changle–Nan'ao Belt behaved as a single tectonic unit since 70 Ma. • Rifting started in the southwestern East China Sea and propagated southwards to the northeastern and then northwestern South China Sea during the Late Cretaceous-Paleogene. The East China Sea Basin is an ideal area for studying the subduction processes linked with this section of the active West Pacific continental margin. The initial rift time associated with the opening of the East China Sea Basin remains strongly controversial. This paper provides a perspective based on the apatite and zircon fission-track analyses of the Changle–Nan'ao Belt, located on the coastal mainland of eastern China. The results reveal a period of rapid exhumation of this belt, trending from 86 Ma in the north to ∼66 Ma in the south. From ∼66 Ma until the present exhumation was very slow. The data and their thermal history modeling results imply that the initial rift time of the East China Sea Basin most likely occurred at 80 – 70 Ma. The younging trend observed from the north to the south of the study area continues along the coastal margin to the northwestern margin of the South China Sea. This suggests the presence of a diachronous rift opening from the southwestern East China Sea during the Late Cretaceous southwards, and to the northwestern South China Sea during the Late Cretaceous – Paleogene. The rapid exhumation is coincident with the rapid decrease in plate velocity of the Izanagi Plate, Pacific Plate, and Neo-Tethyan and Indian Plate during the Late Cretaceous–Paleogene. [ABSTRACT FROM AUTHOR]

• Coqen zircon xenocrysts were originated from ancient recycled continental crustal. • Zircons record the temporal evolution of magmatism and crustal thickness in Coqen. • Lhasa terrane evolutionary process is restored by these zircon xenocrysts. The Cenozoic volcanic rocks of Coqen are located in the western central Lhasa subterrane, where knowledge of the regional lithospheric architecture and related magmatic processes is still lacking. To address this issue, we used in situ U–Pb dating, Lu–Hf isotopic and mineral inclusion analysis in zircon xenocrysts among trachyandesite. These zircons from volcanic samples yielded wide U–Pb ages from 18 Ma to 2424 Ma, showing three significant age peaks at ∼ 246 Ma, 193 Ma, and the most intense one at 128 Ma, which represent three major magmatic processes that developed in the area. The earliest zircon dates suggest the age of volcanic eruption in the Coqen area was not earlier than 18 Ma. Zircon xenocrysts trace elements data point to the continental crust origin of central Lhasa subterrane. We provide the evidence for evolutive magmatism of the Lhasa terrane by calculating ΔFMQ, and show that the oxygen fugacity goes from reduced to oxidized (Cambrian to Miocene). The very low ε Hf (t) indicate a long-term magmatic event sequence, with the Zenong Group having the most vigorous magmatic activity. The old U–Pb ages and T DM C confirmed that an ancient basement of the Precambrian exist in the middle Lhasa terrane. Our work also restores the tectonic and crustal thickness evolutionary process of Coqen area even entire Lhasa terrane. In the back of a series of thickening and thinning processes, the Tibetan crust drastically thickened at ∼ 54 Ma, and gradually created what is now believed to be the thickest crust in the world. [ABSTRACT FROM AUTHOR]

The Central African Fold Belt (CAFB) in Cameroon is characterized by voluminous intrusive rocks hosting microgranular magmatic enclaves (MMEs) whose petrogenesis and tectonic implications remain unclear. Here, we present detailed geochronological and geochemical data of the host rocks and their MMEs from the Linté pluton in central Cameroon. The MMEs are finer-grained than their host syenite and both rocks are composed of alkali feldspar, plagioclase, biotite, amphibole and pyroxenes as main mineral phases. The enclaves show lower Mg#, total alkalis and transition elements contents, and are more HFSEs depleted than the host syenite. Both rocks are characterized by high-K, metaluminous I-type, alkaline to sub-alkaline and magnesian affinities. The Ti-in-zircon thermometer suggests crystallization temperatures of 615–1080 °C and 613–1008 °C for syenites and MMEs, respectively. Their zircon trace element distribution and patterns coupled with whole-rock geochemical features indicate that the Linté intrusive rocks were most likely originated from interaction of mantle-derived magma with crustal material. LA-ICP-MS U Pb zircon analyses yield emplacement age of 599 ± 3 Ma and 597 ± 4 Ma for the host syenite and MMEs, respectively, indicating coeval crystallization date. Integrated whole rock geochemistry, U Pb dating and Ti-in-zircon thermometry data indicate that the Linté syenite were probably formed from a mantle-derived ultrapotassic alkaline melt with significant crustal contribution, while MMEs are likely derived from a similar but separate melt with more fractionation and crustal contamination. The genesis of the host syenite and MMEs magmas started with break-off of the Congo plate after subduction and collision. This initiated an upwelling thermal pulse and underplating of mafic magma which led to partial melting of the Paleoproterozoic crust of the Central Cameroon. • Coeval crystallization of MME1 and host at 597 ± 4 Ma and 599 ± 3 Ma, respectively. • Genesis of syenite from a mantle-derived ultra-K alkaline melt with crustal input. • MME1 melt interacts with crust to produce MME2. • Mantle-crust interaction model is proposed. [ABSTRACT FROM AUTHOR]

The Linxia Basin is an important region for understanding the tectonism and uplift history in the northeast Tibetan Plateau, and also contains rich mammalian faunas of evolutionary significance. In this paper, we conduct a provenance study of Cenozoic sediments, relying primarily on U-Pb dating of detrital zircons, to investigate the exhumation history of surrounding terranes and to gain a better understanding of the relationship between tectonism, basin development and paleoenvironment. Samples were collected from the Maogou section in the central Linxia Basin, which has been recently dated by magnetostratigraphy. Detrital zircon populations show five U Pb age groups of 65–350 Ma, 350–600 Ma, 600–1600 Ma, 1600–2200 Ma and 2200–2600 Ma; however, U Pb age patterns varied up-section, indicating different sources at different times. Sediments from the lower part of the section (>27.8 Ma) were sourced from multiple regions, including the distal East Kunlun Shan, Qilian Shan, and Songpan–Ganzi terranes, and as well as the proximal West Qinling region. Contributions from the Songpan–Ganzi terrane increased considerably during the late Oligocene (27.8–23 Ma), as a result of strong tectonic movements of the northeastern Tibetan Plateau. During the early Miocene (23–17.2 Ma), the northern sources of the Laji Shan–Maxian Shan region supplied more sediments to the basin, indicating the uplift and exhumation of these mountain ranges. Until the middle Miocene (17.2–12.8 Ma), the Songpan-Ganzi terrane and the northern sources dominated the basin sediments, while the northern sources and the Jishi Shan region became increasingly important sources at around 11.6 Ma. This study explores the tectonosedimentary evolution of the Linxia Basin in the northeastern Tibetan Plateau, providing a reference for further research of the paleoclimate and mammalian evolution in this critical region. • Detrital zircon provenance study on sediments in the Linxia Basin. • Sediment sources supplied the central basin at the early stage. • The Songpan–Ganzi direction source largely increased in the late Oligocene. • The north source became an important early to middle Miocene source for the basin. • The Jishi Shan did not influence the Maogou section until around 11.6 Ma. [ABSTRACT FROM AUTHOR]

• U–Pb data from fast pulse LA-ICP-MS is equivalent with conventional U–Pb analysis. • Provenance of the largely unexposed Yeneena Basin revealed. • Exotic sources support a transcontinental transport system across Rodinia. Over ten thousand detrital zircon U–Pb analyses on thirty four samples were undertaken using a fast pulse laser ablation protocol from the Neoprotoerozoic rocks of the largely unexposed Yeneena and northwestern Officer Basins in Western Australia. In addition, conventional laser ablation detrital zircon U–Pb geochronology was carried out on three of the samples. A comparison of the two datasets demonstrated that no statistical significant difference was observed in the detrital zircon spectra between the two techniques. The results of the detrital zircon analyses reveal that after an intial pulse of material dominated by Archean detritus the sediment are dominated by Mesoproterozic sources. This indicates that there is little variation in source materials within and between the identified formations. The major age peaks coincide with magmatic rock ages from within Australia. The results indicate that either the Palaeoproterozoic and Mesoproterozoic terranes remained sources throughout the deposition of the Yeneena and northwestern Officer Basins during the Neoproterozoic, or that recycling of zircons occurred within a quasi-closed system for the duration of sedimentation. The remaining 10 % of grains are difficult to reconcile with magmatic suites of any significant volume within Australia. However, when considering the broader palaeogeographic context at the time the sediments are inferred to have been deposited, rocks from Dronning Maud Land and the Kalahari Craton can supply grains of appropriate ages and are consistent with the known paleocurrent directions. This work demonstrates that there is no significant disadvantage in the application of the fast pulse technique when applied to the collection of U–Pb detrital zircon datasets for the purpose of detrital zircon fingerprinting. However, there is a large upside related to the significant amount of data that can be collected for a given amount of time compared to other more conventional techniques. [ABSTRACT FROM AUTHOR]

[Display omitted] • First report of Mesoarchean (<3.1 Ga) deposition in the Sukma Group, Bastar craton. • Terrestrial detritus of Sukma Group most likely from Western Dharwar and Singhbhum cratons. • Paleoarchean nucleus of Bastar, Western Dharwar and Singhbhum cratons were proximal by ∼ 3 Ga. • Neoarchean (<2.4 Ga) Bengpal Group was therefore deposited after a significant hiatus. Records of terrestrial detritus deposited since the Mesoarchean, preserved in sedimentary basins on cratons, are useful in continental reconstruction. The southern segment of the Bastar craton comprises Paleoarchean cratonic fragments extensively reworked, and intruded by granite batholiths, during the Neoarchean and expose two major groups of supracrustal successions. The Sukma Group, occurring as amphibolite-facies remnants within Neoarchean granitoids are mostly chemogenic supracrustal rocks in contrast to the low-to unmetamorphosed Neoarchean volcano-sedimentary Bengpal Group. In order to resolve their uncertain stratigraphic relationship, detrital zircon U-Pb analyses were carried out to obtain detrital age spectra. The youngest concordant detrital zircon 207Pb/206Pb ages from the Sukma Group metapelite (CB11C) and micaceous quartzite (CH5B) samples places its maximum depositional age at < 3.10 Ga (3128 ± 6 Ma, cumulative maximum depositional age of both samples). In contrast, the micaceous quartzite (samples CB14 and CB18) from the Bengpal Group were deposited after 2.4 Ga (2350 ± 16 Ma, cumulative maximum depositional age of both samples), indicating a considerable hiatus in depositional history of these two supracrustal successions. Comparison with globally compiled age spectra from cratonic Archean-aged metasedimentary successions indicate that a most likely clastic sediment provenance to the dominantly chemogenic Sukma Group was from the Western Dharwar and Singhbhum cratons. The inferred provenance cratons are based on the presence of extensive Mesoarchean granitoid batholiths and, therefore, indicates their proximity at least till 3.0 Ga. In contrast, clastic detritus to the possibly riftogenic volcano-sedimentary Bengpal Group was largely sourced from the voluminous Neoarchean magmatism probably from within the Bastar craton. [ABSTRACT FROM AUTHOR]

• Combination of dating techniques improves accuracy of determination. • Spurious detrital zircon dates post-dating crystallization found by LA-ICP-MS. • LA-ICP-MS studies should routinely chemically abrade zircon prior to analyses. • The oldest Paleoproterozoic glacial event is dated to 2423.1 ± 1.0 Ma. • Anoxic atmospheric settings from the Koegas Subgroup are dated to 2451.5 ± 2.5 Ma. The Transvaal Supergroup, on the Kaapvaal Craton in South Africa, is widely accepted as one of the best-preserved sedimentary archives to constrain planetary-scale environmental changes during the late Archean and early Proterozoic, yet the sedimentation age for certain stratigraphic intervals remains poorly constrained. To improve the temporal control on some of the first-order global changes recorded in these rocks, we carried out U-Pb analyses of detrital zircon populations from several clastic and volcano-clastic sedimentary units of the Transvaal Supergroup. We applied the Chemical Abrasion-Isotope Dilution-Thermal Ionization Mass Spectrometry (CA-ID-TIMS) technique on detrital and volcanic zircon populations that had been previously screened using the Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) technique. We report new maximum depositional age estimates for the Pannetjie (2456.6 ± 7.0 Ma), the Heynskop (2451.5 ± 2.5 Ma), the Makganyene (2423.1 ± 1.0 Ma) and the Hekpoort formations (2248.0 ± 1.1 Ma). A ca. 2.25 Ga-old cluster of LA-ICP-MS analyses in the Makganyene Formation was identified to be spurious, since it was completely removed during the chemical abrasion. Thus, we speculate that circulation of hydrothermal fluids and associated Pb-loss from a radiation-damaged lattice during the emplacement of the much younger Hekpoort Formation or possibly the Ophthalmia Orogeny, recorded in Western Australia, may have reset the U-Pb system of this zircon population. This implies that the accurate maximum depositional age of the Makganyene Formation is ca. 2.42 Ga instead, which denotes the age of the oldest glacial event of global extent during the Paleoproterozoic. Therefore, we suggest that the combination of both dating techniques is essential to ensure accurate maximum depositional age constraints for ancient detrital sedimentary rocks. Additionally, our data provides temporal constraints on a period characterized by major fluctuations in atmospheric oxygen. Finally, and supporting the complex nature of the Paleoproterozoic, linkages between widespread glaciations and atmospheric oxygen fluctuations remain to be explored. [ABSTRACT FROM AUTHOR]

The Terreneuvian Series of the early Cambrian records the first major diversification phase of the canonical Cambrian explosion. However, a paucity of precise radio-isotopic ages for key stratigraphic horizons has resulted in a poor temporal calibration of fossil lowest occurrences (LO) and corresponding rates of evolution throughout the Terreneuvian. Here we present integrated SIMS and CA-ID-TIMS U-Pb analyses on zircons from the basal Shuijingtuo Formation in the Yangtze Gorges area, South China. The dating results provide a depositional age of 526.43 ± 0.54 Ma for the basal Shuijingtuo Formation, and compiled detrital zircon U-Pb dates from the Ediacaran-Cambrian transitional strata in the Yangtze Gorges area indicate their local provenances. The new high-precision date provides a minimum age constraint on the ZHUCE (Zhujiaqing positive carbon isotope excursion) and LOs of Watsonella crosbyi and Aldanella attleborensis in South China, and allows correlation of ZHUCE with either 5.5p or 5p/I′ in Siberia and Morocco. We construct two models of the Ediacaran-Cambrian transitional timescale based on the two alternative correlations of the ZHUCE. The first model correlates the ZHUCE with 5.5p and yields significantly diachronous LOs of W. crosbyi and A. attleborensis between the Siberian Platform and South China. In contrast, the second and our preferred model equates ZHUCE with 5p/I′ and implies relatively synchronous LOs of W. crosbyi and A. attleborensis between the Siberian Platform and South China. In the preferred model, the couplet of ZHUCE/5p/I′ and LOs of W. crosbyi and A. attleborensis serves as a reliable combination to bracket the base of Cambrian Stage 2. • The basal Shuijingtuo ash bed at Yanjiahe section is dated at 526.43 ± 0.54 Ma. • The ZHUCE is correlated to either 5.5p or 5p/I′ in Siberia and Morocco. • Potential markers for the Cambrian Stage 2 are evaluated based on the new date. [ABSTRACT FROM AUTHOR]

To decipher the geomorphic and drainage evolution between Tibet and the South China Sea (SCS), the Cenozoic source-to-sink evolution of the central northern SCS has always been a research hotspot. However, previous provenance studies mainly focus on Cenozoic deposits in the central Pearl River Mouth Basin (PRMB) and their implications on the evolution of the Pearl River and the source areas in South China, leaving the provenance characteristics of other places, especially the western and eastern PRMB, and their relationship with surrounding tectono-geomorphic evolution unknown. We obtained some new data from the western and eastern PRMB, which allows for a complete story about the Cenozoic source-to-sink evolution of the central northern SCS. Based on comparative analyses of zircon U-Pb and geochemical data of Cenozoic sediments and pre-Cenozoic bedrocks in the PRMB as well as modern river sand in surrounding potential drainage systems, considering tectonic and geomorphic evolution in/around the SCS, we find that the Cenozoic provenance of the central northern SCS varies both in time and space. Generally, most of the Eocene sediments show almost the same age spectra as their adjacent pre-Cenozoic bedrock highs/uplifts, implying that intrabasinal source-to-sink processes dominated before the latest Eocene; the Oligocene and upward deposits display similar age spectra to modern river sand in adjacent drainage systems, suggesting that extrabasinal have taken over since Oligocene; while sediments between them show more complex age spectra that vary vertically, indicating that provenance shifts from intrabasin to extrabasin occurred during Late Eocene. Geomorphic changes resulting from regional tectonic activities between Tibet and the SCS control the source-to-sink and drainage system evolution in/around the central northern SCS. The ENE-tilting axial topography and its differential evolution of the northern SCS have controlled the supply and changes of detritus from Central Vietnam eastwards to the Zhu II Depression since the Eocene. By contrast, the gradual topographic inversion of South China from W-tilting to E -tilting has resulted in the headward erosion and growth of drainage systems in South China since the latest Eocene and subsequent provenance shift and evolution in the central northern SCS. With the geomorphic and drainage evolution, the Pearl River provided detritus mainly to the central PRMB, while other smaller drainage systems fed to their adjacent area, and the South China detritus supply has become dominant in the central northern SCS since the Oligocene, in which the components from Cathaysia Block remained as the main contributor, though detritus from Yangtze Block did increase gradually. • Intrabasinal source-to-sink processes dominated in the central northern SCS in the Eocene. • Most drainage systems began providing detritus to the central northern SCS in the Late Eocene. • Extrabasinal source-to-sink processes have superseded intrabasinal ones since the Oligocene. • Surrounding tectono-geomorphic evolution drove source-to-sink changes in the central northern SCS. [ABSTRACT FROM AUTHOR]

[Display omitted] • Devonian migmatite-granite complex developed a sub-horizontal HT/LP fabric. • Structures across the crust of the Chinese Altai advocate Devonian extension. • Subduction retreat induced crustal extension and promoted metallogenic evolution. Crustal extension due to the retreat of subduction system has been assigned as an important mechanism governing the Devonian tectonic evolution of the Chinese Altai Orogen in central Asia. While the extensional regime has been repeatedly inferred from petro-structural (petrographic and structural) records preserved in the orogenic upper crust sedimentary covers and orogenic middle crust schists, such records have rarely been documented in the deep crustal migmatitic and/or magmatic rocks. This gap is filled in this study by applying combined petro-structural analysis in conjunction with zircon and monazite U-Pb geochronology on representative orogenic lower crustal migmatite-granite complexes. These complexes are characterized by the development of a sub-horizontal foliation associated with extensional melt‐filled shear bands. The foliation commonly contains garnet-sillimanite ± K-feldspar ± cordierite-bearing metamorphic assemblages that are compatible with a low-pressure/high-temperature thermal regime. In addition, such mineral assemblages are usually found to replace pre-existing middle-pressure/middle-temperature Barrovian-type ones, reflecting a tectonic switch from thickening to extension. New monazite and zircon U-Pb age data, together with regional pre-existing ages, suggest that the sub-horizontal high-temperature foliation formed during a period of 420–390 Ma. Combined with previously published data, our data reinforce that a crustal-scale extensional tectonic regime developed in response to retreating of subduction system governed the geodynamic evolution of the Chinese Altai Orogen during Devonian times. This process led to regional anatexis of the pre-existing Ordovician accretionary wedge complex, facilitated the formation of stabilized and vertically stratified continental crust, and promoted the metallogenic evolution in the region during the Devonian. [ABSTRACT FROM AUTHOR]

The eastern and southern Precambrian basement of Mexico is composed of crustal blocks linked to northern Amazonia before and during the assembly of the Rodinia supercontinent. In this paper, we examine an extensive basement block known as the Sierra de Juárez Complex (SJC) in southern Mexico by integrating fieldwork, in-situ zircon U–Pb geochronology by LA-ICPMS and whole-rock geochemistry by X-ray fluorescence. The results provide evidence for a continuous low-to high-grade metamorphic succession here re-defined as the Pochotepec suite (PS), which comprises an upper lithodeme with volcanosedimentary precursors and a lower lithodeme that includes mafic to intermediate orthogneisses and migmatites. The analytical results suggest that the PS protoliths originated in a continental-arc tectonic setting ca. 1080-1050 Ma along the northern edge of Amazonia before the consolidation of Rodinia. In addition, xenocrystic zircon U–Pb analyses indicate the presence of a recycled older crust of ca. 1200–1300 Ma. Finally, U–Pb data of recrystallized zircon rims and younger metamorphic zircon grains recorded the timing of metamorphism and anatexis of the PS during the early Tonian (954-933 Ma). The crystallization ages of two trondhjemitic leucosomes of 954 and 933 Ma strongly support the migmatization age. The Tonian metamorphic/anatectic episode of the PS differs in grade and age from the typical metamorphism related to the amalgamation of Rodinia reported in Mexico and Colombia (granulite-facies at ca. 990 Ma). Therefore, we interpret this event as produced by either post-orogenic crustal collapse or contractive tectonics. • The Pochotepec suite (PS) in southern Mexico belongs to the Sierra de Juárez Complex and consists of a Stenian – Tonian metamorphic sequence. • The Pochotepec suite originated during continental-arc magmatism along the leading edge of Amazonia during the late Stenian. • The Pochotepec suite underwent Tonian lower-to-medium-grade metamorphism and anatexis after the Rodinia assembly. • The Pochotepec suite followed a different tectonic evolution relative to the Oaxaquia-Putumayo block after the Rodinia assembly. • The Pochotepec suite correlates with the Chiapas Massif Complex in southeastern Mexico. [ABSTRACT FROM AUTHOR]

In the central region of the Precordillera, San Juan Province, Silurian silicoclastic sedimentites of the Los Espejos Formation crop out in the Jáchal River area. To the south of this region, an equivalent unit is recognized in the San Juan River area (Tambolar Formation). Both units present similar lithological characteristics, however, it has not yet been defined if they share source areas of detrital contributions. On the other hand, for the Jáchal River sector, it is proposed to establish if there were changes in the regions from where the sub-basin received sediment contributions during the Devonian, which can be seen reflected in the detrital zircon contribution patterns of the overlying unit (Talacasto Formation). The present work is part of a series of studies tending to determine the nature and provenance of the Silurian-Devonian sequences of the Central Precordillera. On this occasion, detrital zircon patterns of the detrital sources of the Los Espejos Formation are analyzed and compared with the information obtained for the Silurian Tambolar Formation (San Juan River area) and the overlying Devonian Talacasto and Punta Negra formations (Jáchal and San Juan rivers areas). To characterize and compare the studied units, different methodologies were applied, namely sedimentary petrography, heavy minerals studies, and morphological and isotopic analyses of detrital zircons. The analysis of thin sections allowed determining textural and compositional parameters. Through the predominance of detrital minerals, it was possible to establish that the studied units are composed of quartzite-type rocks coming from mature areas, with low percentages of lithic components and abundant opaque heavy minerals of the hematite group. The study of heavy minerals, especially morphological and typological parameters of detrital zircons, allowed to establish recycled and plutonic sources as main modes, as well as the changes that occurred during the basin filling dynamics for Silurian and Devonian times. On the other hand, U–Pb isotopic analysis in detrital zircons indicate that the Pampean-Brasiliano orogenic cycle composes the main source of detritus with ages between 511 and 816 Ma. In second place are the Mesoproterozoic ages, represented by the interval from 1000 to 1350 Ma. The youngest detrital ages show a maximum sedimentation age of 478.5 ± 4.4 Ma (Tremadocian), indicating that younger sources of contribution correspond to the Famatinian Orogen. The Kolmogorov-Smirnoff test revealed that the studied Silurian-Devonian units studied have similar patterns of sedimentary contributions, which suggests that the sources of provenance were common in both regions and remained active throughout the entire time interval, without significant changes. • The Los Espejos Fm evidences multiple cycles of erosion-transport-sedimentation. • The Pampean-Brasiliano orogen represents the main source of sediments. • The provenance proxies indicate a connection between the Jáchal and San Juan Rivers depocenters. • The main sources of sediments are the Western and Eastern Pampean Ranges. [ABSTRACT FROM AUTHOR]

The Guleman Ophiolite is located in the southeast of Turkey and mainly consists of harzburgites and dunites hosting economically viable chromitite bodies, and lesser amounts of cumulate and isotropic gabbro, diabase dykes, pyroxenite and locally plagiogranite. This study reports the combined whole-rock geochemical and radiogenic isotope (Sr and Nd) data for gabbro and diabase dykes, and in-situ zircon U-Pb geochronological data for plagiogranite and gabbro from the Guleman Ophiolite. Two different geochemical groups were determined based on immobile minor and trace elements, and radiogenic isotope characteristics of gabbro and diabase dykes investigated here. The first group is represented by boninites and displays highly depleted elemental patterns compared to NMORB, and spoon-shaped rare earth element profiles. Contrarily, the second group resembles back-arc basin basalts and is characterized by NMORB-like rare earth element patterns associated with negative Nb anomalies. The boninitic samples are characterized by less radiogenic 143Nd/144Nd (i) (0.51229 to 0.51267; ƐNd = −4.8 to +2.7) and more radiogenic 87Sr/86Sr (i) (0.70549 to 0.70758) isotope compositions compared to the back-arc basin basalt-like samples (143Nd/144Nd (i) = 0.51289 to 0.51296; ƐNd = +7.0 to +8.4; 87Sr/86Sr (i) = 0.70496 to 0.70629), indicating derivation from distinct and/or heterogeneous mantle source regions within a supra-subduction zone. The LA–ICP–MS zircon U-Pb analyses yielded concordant late Cretaceous ages for gabbro (82 ± 2.9 Ma) and plagiogranite (79.9 ± 0.8 Ma) samples. The overall geochemical, isotopic and geochronological data presented here suggest that the Guleman Ophiolite consists of forearc and initial back-arc spreading sections of oceanic crust, which may have been formed in an intra-oceanic subduction zone within the Berit Ocean (northern branch of the southern Neo-Tethyan ocean). Moreover, the generation of continental arc magmatism (i.e. Baskil and Esence Granitoids) was well-documented on the active margin of the Malatya-Keban Metamorphics to the north. Therefore the closure of this oceanic basin should have resulted in multiple coeval northward subduction events during the late Cretaceous. • The Guleman Ophiolite could have been formed in an intra-oceanic subduction zone. • The mafic rocks show boninitic and back arc-like geochemical signatures. • Late Cretaceous ages of 79 Ma and 82 Ma are reported for plagiogranite and gabbro. • A multiple northward subduction model is plausible for the Berit Ocean. [ABSTRACT FROM AUTHOR]

• Correlation of profiles of the Volyn LIP using zircon CA-ID-TIMS analysis. • Discovery of younger than 567 Ma felsic phase of Volyn volcanism. • Constraining ages of glaciations older and younger than basalt flows. • Constraining ages of Redkino-Kotlin boundary and Podillya Ediacaran biota. • Correlating Podillya Ediacaran with the felsic phase of Volyn volcanism. Combined single zircon crystal CA-ID-TIMS U-Pb dating, micropaleontological study, and quantitative XRD analysis were used to correlate sections of the Podillya-Moldova Ediacaran succession with sections of the Volyn Large Igneous Province (Volyn LIP). Five U-Pb zircon ages were obtained from Volyn LIP rocks, and four from three distinct Podillya bentonite horizons. Biostratigraphic determinations were made for one section in Volyn, and two sections in Podillya. It was concluded that Volyn LIP activity had two phases. A first phase of mafic and felsic magmatism was characterized by eruption of numerous basalt lava flows, and lasted from c. 580 to 567 Ma; a second phase of pyroclastic felsic magmatism, with no lavas, lasted from 567 to c. 545 Ma. The two phases can be distinguished in the quantitative mineral composition of rocks from the Kobryn 1K borehole in western Belarus. In the central area of the Volyn LIP, near Brest, rocks of the felsic phase were removed by erosion before deposition of the Kotlin subgroup. The Podillya Ediacaran succession, from the top of the Hrushka formation to the top of the Kalyus beds, (i.e. the Mohyliv-Podilsky group), hosts soft-bodied organisms. This succession corresponds to the felsic phase of the Volyn LIP. The age of the Redkino-Kotlin subgroup biostratigraphic boundary, at the base of the Nagoryany formation, is constrained at 555–545 Ma, close to the end of the Volyn LIP activity. The newly discovered glaciation in Volyn is dated as c. 567 Ma. The period of development of kaolinitic paleosols on top of the Volyn LIP effusive rocks is dated at c. 570–550 Ma. [ABSTRACT FROM AUTHOR]

The genesis of Precambrian granitic batholiths related to supercontinent assembly is controversial, especially regarding their generating processes and tectonic settings. The present study focused on the Pelotas Batholith (Magmatic-arc domain) of the Dom Feliciano Belt, which comprises the southern segment of the Mantiqueira Province in southeastern South America. New U–Pb and Lu–Hf zircon data from plutonic rocks with evidence of magma mixing and mingling, as well as assimilation of wall rocks, suggest multi-stage magmatism related to flare-up episodes of intense magmatism, potentially triggered by changes in the tectonic setting. U–Pb zircon analyses yielded crystallization ages of granodioritic gneiss xenolith at 691.5 ± 7 Ma, microgranodiorite xenolith at 645.9 ± 3.7 Ma, host monzogranite at 634.4 ± 4.4 Ma, and intrusive syenogranite at 620.1 ± 4.7 Ma, all intruded by syenogranitic pegmatite at 606.9 ± 1.7 Ma. Other analyses were performed on calc-alkaline granite (633 ± 4 Ma) and peraluminous granite (609.6 ± 2.2 Ma). The Lu–Hf data highlights a model age interval ranging from 1.7 to 1.3 Ga with εNd values between −4 and 1, except for the pegmatite sample which also includes Paleoproterozoic and Archean model ages (3.3-1.6 Ga) and εNd values between −33 and −1. Furthermore, the acquired data, together with the gathered dataset Dom Feliciano Belt granites, emphasizes a contribution from slightly juvenile to crustal sources, with model ages ranging primarily from Statherian-Orosirian to Mesoproterozoic. Signature patterns are consistent with sources from African basement rocks. • The studied magma mixing outcrop represents the Granite belt's fractal evolution. • The magmatic suites are primarily classified as I-Type and S-Type granites. • The Hf isotopes present mainly Meso-to Paleoproterozoic model ages (1.7-1.3 Ga). • The εHf values are primarily slightly negative to positive. • The U–Pb dataset shows well-defined intervals of magmatic pulses. [ABSTRACT FROM AUTHOR]

The northern shelf of South China Sea is an important passageway for the transportation of sediments from the terrigenous source to the oceanic sink, but the provenance and dispersal patterns of sediments remain largely unclear. Here we report the results of zircon grain-size analysis and U-Pb geochronology to investigate the sediment provenance and illustrate the transport and dispersal patterns of sediments on the continental shelf of the northern South China Sea. The results show that detrital zircon U-Pb ages within sediments are characterized by a major peak at ca. 150 Ma, as well as three minor age populations at ca. 240 Ma, 400–500 Ma, and 900–1000 Ma. A detailed provenance study suggests that these sediments were primarily derived from both the Pearl River catchment and the drainage systems in Taiwan Island. Our study confirms that the transportation and dispersion of sediments were largely controlled by both topography and hydrodynamics of sea. The sediments in the inner continental shelf were transported from the Pearl River drainage system and subject to the Guangdong Coastal Current, whereas the sediments in the middle and outer continental shelf were markedly influenced by the South China Sea warm current. This study elucidates the transport and dispersal patterns of detrital sediments in the marginal sea by comprehensive analyses of detrital zircon grains. • Zircon grain-size and U-Pb dating were utilized to decipher the provenance and dispersal patterns. • The sediments were primarily derived from the sources of Pearl River and Taiwan Island. • Redistribution of sediments was influenced by the shelf current as the rising of sea level. • Different mineral grain sizes settling differentially can affect sediment provenance. [ABSTRACT FROM AUTHOR]

During the late Neogene, global climate underwent a long-term transition to cooler climates that culminated in the Quaternary icehouse conditions. In the East Asian terrestrial realm, atmospheric dustiness increased, and the volume of aeolian dust deposits expanded significantly. The Neogene Red Clay deposits, located on the Chinese Loess Plateau (CLP), provide an exceptional geologic archive to investigate pre-Quaternary climates and environments. Constraining the provenance of the Red Clay is crucial for unravelling the links between late Neogene Central-East Asian climate, tectonics and desertification. However, Red Clay provenance is highly debated and data are scarce. In this study, we have used a multi-proxy approach at a high sampling resolution to study the provenance of the c. 7–2.6 Ma Baode Red Clay. Our data consist of joint detrital zircon U-Pb ages and detrital rutile trace element geochemistry of the Baode Red Clay, and of a massive rutile geochemistry dataset from 14 potential dust source areas. The data indicate that the Mio-Pliocene and Plio-Pleistocene global climate transitions were coupled with gradual dust provenance shifts. We propose these shifts indicate the intensification of East Asian winter monsoon and/or enhanced Central-East Asian drying as a response to global cooling. We also identify temporary Pliocene provenance changes that interrupt the long-term winter monsoon -controlled dust transport at c. 4 Ma and c. 3.5 Ma. Several indicators point to dust transport by the westerly jet at c. 4 Ma, possibly caused by a shift in the jet position as a response to global cooling, and/or enhanced wet deposition caused by intensified summer monsoon. Alternatively, the role of the paleo-Yellow River should be investigated further. We infer the 3.5 Ma provenance signal was caused by increased Yellow River -transported material from eroding Northeastern Tibetan Plateau and/or western CLP. Implications of our results not only shed light on the links between late Cenozoic global climate change and Central-East Asian dust cycle, but also provide detailed information to further investigate the late Neogene regional geomorphology and its effects on dust emission, transport, and deposition. Our combined rutile-zircon analysis also verifies that a multi-proxy single-grain approach that targets different types of primary source rocks is needed for reliable provenance analysis of the CLP dust. • A high resolution provenance record of the 7–2.6 Ma aeolian Baode Red Clay. • Mio-Pliocene and Plio-Pleistocene climate changes caused gradual provenance shifts. • Temporary provenance changes at c. 4 Ma and 3.5 Ma. • Joint detrital rutile and zircon analysis targets metamorphic and igneous sources. • An extensive detrital rutile dataset from 14 potential dust source areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • New data on interbedded metavolcanic rocks inform the origin of DFB complexes. • Metamorphic complexes of the DFB Central Sector show two unrelated magmatic events. • Elemental and isotope data indicate an Andean-type magmatic arc at 800–770 Ma. • New U-Pb zircon ages reveal Passo Feio metavolcanic protoliths of 580 ± 2 Ma. • The volcano-sedimentary complexes have a common late-orogenic evolution at 580 Ma. The geochemical and isotopic signatures of magmatic events preserved in deformed metavolcano-sedimentary sequences may inform about geological setting and original basin stratigraphy. This paper discusses elemental and isotopic geochemical literature data on metavolcanic rocks interleaved with highly-deformed metasedimentary rocks from the Dom Feliciano Belt central sector, southernmost Brazil: the high-grade Várzea do Capivarita, and the lower greenschist to amphibolite facies Porongos and Passo Feio complexes. We also provide new geochemical data for seven samples and two U-Pb zircon determinations. REE patterns, together with geochronological data, permit to sort the dataset into three main groups: i) Group 1 - LaN/YbN ≈ 10, Eu/Eu* = 0.38 to 0.86; ii) Group 2 - LaN/YbN = 12 to 44, no Eu anomaly, and iii) Group 3 - negative Eu anomaly (Eu/Eu* ≈ 0.70), but higher LREEs absolute values (LaN/YbN ≈ 22), and rare basic metavolcaniclastic rocks (Bmvc). New U-Pb zircon analyses of two Passo Feio acidic metavolcanic rocks yield a crystallization age of 580 ± 2 Ma (2σ). Group 1 samples account for a magmatic event at 800–770 Ma in the Várzea do Capivarita and Porongos (Cerro da Árvore sequence) complexes. They represent a magmatic association produced from subduction-related sources, with crustal contribution shown by 87Sr/86Sr (790 Ma) > 0.715 and ƐNd (790 Ma) from −5 and −11 (up to –22). Groups 2 and 3 account for a magmatic event at ca. 600 to 580 Ma in the Passo Feio and western Porongos (Capané sequence) complexes. Groups 2 and 3 rocks are interpreted to have been sourced from subduction-related enriched mantle without major crustal contamination, with 87Sr/86Sr (580 Ma) = 0.7035–0.7050 and ƐNd (580 Ma) > -10. For the basic metavolcanoclastic sample (Bmvc), the data suggest mantle-derived origin without significant contribution of subduction-related sources, possibly indicating multiple sources for this newly-described and not yet fully understood Ediacaran magmatism. Our comparative study leads to the novel conclusion of a shared tectonic evolution between the Passo Feio Complex and the western Porongos Complex at ca. 600–580 Ma. They also corroborate a shared tectonic evolution between the Porongos Complex and Várzea do Capivarita Complex at ca. 800–770 Ma, as reported by previous authors. [ABSTRACT FROM AUTHOR]

When plate tectonics emerged on Earth is one of the most fundamental questions in geosciences. Nowadays, different arguments from diverse research fields (petrology, structural geology, geochemical and numerical modeling) postulate that the lithospheric subduction began sometime in the Archean-Paleoproterozoic with different styles. This study provides robust petrologic evidence for the modern-style plate tectonics onset in the Paleoproterozoic featured by low geothermal gradients. We investigated the Salma eclogite association from the Precambrian Belomorian Province (BP) on the Fennoscandian Shield (Russia). Based on the garnet chemical annuli (major and trace elements) and therein mineral inclusions, plus comprehensive zircon isotopic-chemical analyses, we establish the prograde metamorphic history of the eclogite, leading to peak conditions of 2.2-2.3 GPa, 650-670 °C prior to 1.93 Ga. We thus, for the first time, conclude cold subduction (303 ± 16 °C/GPa) proceeded in the BP, connected with the Lapland-Kola Orogen (LKO). Such conclusions are clearly against the previously argued Archean subduction scenario and "warm" tectonic setting in the BP, and are very important for understanding the geodynamics of the early Earth. Furthermore, in the light of other scarce coeval "cold" Paleoproterozoic high pressure (HP) metamorphic rocks elsewhere, we posit that modern-style plate tectonics already operated in the form of the Columbia Supercontinent. • The Precambrian Belomorian eclogite preserves prograde metamorphic imprints and records low T/P thermal gradient. • The cold Belomorian eclogite was formed 1.9 billion years ago during oceanic subduction. • The previously argued Archean eclogitization and warm subduction are highly unlikely. • Modern-style plate tectonics onset in the form of the Columbia supercontinent is advocated. [ABSTRACT FROM AUTHOR]

The precursor basin of the Araçuaí – West Congo Orogenic System (AWCO) formed a large gulf within the São Francisco – Congo Paleocontinent (SFCP), where the diamictite-bearing Macaúbas Group was deposited during the Neoproterozoic. However, the lack of robust age constraints on the Cryogenian glaciogenic successions prevents correlation to one or both of the Cryogenian Snowball Earth glaciations. The present study introduces new field data and new U–Pb detrital zircon data from diamictite-bearing units on the southern margin of the São Francisco Craton, in the northeastern Araçuaí Orogen. This region is much closer to possible Ediacaran-Cryogenian igneous rocks of the southern São Francisco craton than other regions previously studied for the Macaúbas Group, enhancing the probability of detecting detrital minerals from those rocks, if they were involved as source areas. In the studied region, the Macaúbas Group is composed of metadiamictite with sparse clasts and schistified metagraywacke with bulk mineralogy similar to the quartz-muscovite-feldspar matrix of the metadiamictites. U–Pb (LA-MC-ICP-MS) dating of 182 detrital zircon grains from the Lower Chapada Acauã Formation forming the syn-glacial sequence yielded main age peaks at 939 ± 3 Ma, 1409 ± 10 Ma, 1822 ± 8 Ma, 2044 ± 7 Ma, 2551 ± 9 Ma and 3103 ± 19 Ma. The youngest concordant zircon grain found in this study aged 753 ± 12 Ma. U–Pb (LA-MC-ICP-MS) dating of 104 zircon crystals from a granitic clast recovered from the diamictite exhibits highly discordant data plotting in distinct Discordia lines with upper intercept ages of 2.0 Ga, 2.5 Ga, 2.6 Ga and 3.2 Ga, indicating derivation from the adjacent cratonic basement. The U–Pb age spectra suggests important contribution from the Archean and Paleoproterozoic basement of the São Francisco – Congo paleocontinent and metamorphic complexes, from the Mesoproterozoic intrusive and volcanic rocks of São Francisco Craton, and from the Tonian Salto da Divisa Suite. Despite the relative abundance of Cryogenian zircon grains in the surrounding prospective source areas, the studied rocks lack this interval age. The glaciogenic events in the Macaúbas basin system probably did not sample rocks with these age intervals due to the general characteristics of this type of deposit or because the sources were not exposed. Thus, the lower diamictite-bearing units of the Macaúbas Group in the northeastern São Francisco craton were deposited after ca. 753 Ma, but their correlation to either the Sturtian or Marinoan global glaciations remain speculative. • U–Pb detrital zircon data of Chapada Acauã Formation reveals a younger sedimentation age. • Top diamictite bearing unit of Macaúbas Group with Upper Tonian detrital contribution. • Data corroborates coevality of Upper Macaúbas basin system and Jequitinhonha Complex. [ABSTRACT FROM AUTHOR]

Combined U-Pb-Hf-O isotopic analyses of zircons are useful probes to investigate the origin and temporal evolution of long-lived magma reservoirs feeding large eruptions. This study presents a complete dataset of zircon Hf-O isotopes of the latest five Toba eruptions in the Quaternary. The new isotopic data differ slightly within and between eruptive units, with the majority of zircons having ε Hf values between −8 to −5 and δ18O values between 6 and 6.8. These Hf-O isotopic compositions of zircons were considered to inherit from an enriched and slightly heterogenous magma source. Specifically, zircons of the Oldest Toba Tuff (OTT) have rather restricted and constant Hf-O isotopes, which may crystallize from a reservoir protractedly supplied from the same magma source. Zircons of the Middle Toba Tuff (MTT) have a large range of δ18O values varying from ~6 to 8, with low ε Hf values extending to −14, indicating shallow-level crustal contamination. The largely negative correlations between ε Hf and δ18O for zircons from the MTT are indicative of contamination of high-δ18O crustal materials, whereas those of the positive correlations for zircons from the Youngest Toba Tuff (YTT) imply contamination of hydrothermally altered low-δ18O crustal materials. It is important that the Hf-O isotopes of all the zircons do not record any single batch of magma that was derived from partial melting of depleted mantle peridotites, but are consistent with an enriched and heterogenous mantle source hybridized by the subducted sediments, followed by contamination of low-δ18O or high-δ18O materials during their ascent to the surface or storage in the shallow magma reservoirs. The increase of zircon δ18O values towards eruptions in both the MTT and YTT suggests that the two eruptions might be accompanied by roof collapse that added high-δ18O materials to the magma. Thus, assimilation of high-δ18O crustal materials could be a possible trigger for the MTT and YTT eruptions. • Toba volcanic rocks were derived from an isotopically enriched and heterogenous mantle source. • Hf-O isotopes of the MTT zircon crystals exhibit characteristics of shallow-level crustal contamination. • The YTT magma reservoir was contaminated by both high- and low-δ18O crustal materials. • Assimilation of high-δ18O materials by roof collapse could be a likely eruption trigger for the MTT and YTT eruptions. [ABSTRACT FROM AUTHOR]

• The Sassandra-Cavally domain is located across the Paleoproterozoic and the Archean teranes. • Rocks consist of migmatitic gneisses, metasediments and a granitic intrusion. • U-Pb ages obtained on zircon span from the Mesoarchean to the Paleoproterozoic. • Hf compositions show mixed crustal growth processes at 3328–2812 Ma and 2213–2088 Ma. Crustal evolution in the south West African Craton is dominated by a significant input of juvenile material into the crust at ca. 2.1 Ga and it remains unclear how much of the Paleoproterozoic continental mass was influenced by the presence of pre-existing Archean crustal domains. The Sassandra-Cavally (SASCA, Côte d'Ivoire) domain is strategically located east of the Sassandra shear zone at the transition of the Paleoproterozoic and Archean terranes of the Leo-Man shield. Combined U-Pb and Lu-Hf isotopic analyses by LA-(MC-)ICP-MS were acquired on zircon grains extracted from migmatitic gneisses, metasedimentary rocks and a granitic intrusion. The migmatitic gneisses, yield Archean ages between ca. 3330 and 2810 Ma with ε Hf ranging from −9.4 to + 3.3 and a metamorphic age at 2076 ± 6 Ma. They are tentatively interpreted as orthogneisses extracted from the mantle during the Paleoarchean and reworked substantially in the Mesoarchean. Detrital zircon grains from metasedimentary units adjacent to the Archean migmatitic gneisses yield ages ranging from ca. 2213 to 2088 Ma with ε Hf ranging from + 0.0 to + 5.5, indicating derivation from juvenile Paleoproterozoic source rocks. A granite intrusion was dated within uncertainty of the metamorphic age at 2084 ± 6 Ma. It exhibits a hybrid isotopic signature with ε Hf forming two distinct clusters between −4.9 and −8.5, and between + 2.2 and + 6.5 for inherited zircon grains dated between ca. 2343 to 2100 Ma. The near continuous U-Pb age record from this early Mesoarchean event to the Neoarchean is associated with constant initial 176Hf/177Hf suggesting for an ancient lead loss event at ca. 2800 Ma or a prolonged period of zircon dissolution/precipitation and/or crystallization. This early period is followed by peaks of zircon dates highlighting crustal extraction during the Eoeburnean (ca. 2250 to 2150 Ma) and Eburnean orogenies (ca. 2140 to 2100 Ma). The absence of detrital zircon of the ages similar to those of migmatitic gneisses (∼3200–2800 Ma) in Paleoproterozoic metasediments suggests their deposition distal from the Archean terranes followed by a tectonic assemblage of the SASCA domain during the later stages of the Eburnean orogeny. [ABSTRACT FROM AUTHOR]

[Display omitted] • Transition from stable (S-type granites, - ε Nd) into stretched continental margin(I-type granitoids, + ε Nd) • Linkage of NW India, Seychelles, SE Pakistan, E-Oman indicates Tonian continent to volcanic arc transect. • Constitution of a volcanic arc at ca 1 Ga. • 130 my of cordilleran-type continental arc setting along Neoproterozoic NW Indian continent. • Episodic magmatic activity at 840 Ma, 825 Ma and 770 Ma. Here we introduce a new model for a Tonian active continental margin in the Neoproterozoic western foreland of the Delhi Fold Belt of NW India. This study gives indication for a transition from continental crust into an active arc setting prior to emplacement of the volcano-plutonic Malani Igneous Suite. Erinpura Granites (890 to 860 Ma) are exposed in a large area west of the Delhi Fold Belt in NW India. The Erinpura Granites are S-type (ε Nd −10 to −3) whereas granites, granodiorites and gabbros exposed in the westernmost basement outcrops (Bhinmal, Harsani) are I-type granitoids and show positive Nd ratios (ε Nd + 4 to + 6). These intrusions are derived from crustal melting with a lithospheric component and affinity to a subduction setting, as can also be inferred from trace element ratios. Our study places the Bhinmal granite as youngest intrusion in this setting (U-Pb analyses of zircon 794 ± 17 Ma and titanite 793 ± 19 Ma). High temperature linear solid-state fabrics in the granites indicate intrusion and deformation during crustal extension. After uplift and exhumation bimodal dykes and granites of the Malani Igneous Suite (770–750 Ma) intruded into this older crust (pre-Malani basement). An evolutionary model for a Tonian active continent margin is established by integrating data from Nagar Parkar in East Pakistan and Neoproterozoic basement inliers in East Oman. The data indicate 130 Myr of ongoing subduction (900 to 770 Ma) along the continental margin. Magmatic activity is identified as episodic with three major pulses starting at ca. 840 Ma, ca. 825 Ma and ca. 770 Ma. High temperature melting constitutes the last Tonian magmatic pulse (Malani Igneous Suite) attributed to roll-back of the subducting slab. The implications for Neoproterozoic plate tectonic reconstructions are discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Grenville-age terrane is identified in the Qilian orogen. • The Precambrian basement of the Qilian orogen is divided into four distinct mega-sequences. • ∼475 Ma metamorphism was related to the subduction of the Proto-Tethys Ocean. The Qilian orogen at the northeastern margin of the Tibetan Plateau records a complete history from continental breakup to oceanic basin evolution and back to continental collision during the Neoproterozoic to Paleozoic interval. The Qilian Ocean, as a branch of the Proto-Tethys Ocean, was connected to the Iapetus Ocean but is lesser known than its two more famous counterparts. This paper presents zircon U-Pb and biotite-muscovite 40Ar/39Ar isotope data from the Yemananshan Complex in the western Central Qilian belt to assess the age and provenance of late Mesoproterozoic-early Paleozoic successions in the Qilian orogen. The results indicate the Central Qilian belt is characterized by Late Mesoproterozoic-early Neoproterozoic orogenesis with magmatism from 1200 Ma to 900 Ma and clastic metasedimentary rocks deposited between 1050 and 920 Ma. Statistical analysis of detrital zircon data and auxiliary temporal information from the Qilian orogen affirms the notion that sedimentation occurred in four distinct megasequences: (1) 1950–1850 Ma, the oldest known strata, (2) 1250–920 Ma, during Grenvillian-Sveconorwegian orogenesis, (3) 840–760 Ma, the disintegration of Rodinia, and (4) 650–550 Ma, which is typical of the orogenic belts that sutured the Gondwana continental blocks. Metamorphic zircon and 40Ar/39Ar isotope data indicate early Paleozoic metamorphism at ca. 475 Ma, which overlaps with magmatic activity associated with arc-back-arc basin development in the Central Qilian belt, which was associated with subduction of the Proto-Tethys in eastern Gondwana. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Dantazi Complex of the North Hebei Terrane in the northern North China Craton. • Late Neoarchean diversified granitoids were derived from crust-mantle interactions. • These crust-mantle dynamic processes developed in a continuous retreat arc setting. The Dantazi Complex in the North Hebei Terrane is located in the middle segment of the northern North China Craton, and plays a crucial role for understanding the early Precambrian crustal evolution of the craton. The Dantazi Complex is composed mainly of late Neoarchean tonalites-trondhjemites-granodiorites, potassic granites, sanukitoid granodiorites-monzodiorites and quartz syenites, which were emplaced by Paleoproterozoic gabbroic stocks. SHRIMP and LA–ICP–MS zircon dating analyses have revealed that the Neoarchean diversified granitoids of the Dantazi Complex were formed in ∼2.52–2.47 Ga, and preserved ∼2.60–2.53 Ga inherited/captured zircon ages. All these rocks experienced early metamorphism and deformation at ∼2.40 Ga, later granulite facies metamorphism at ∼1.80 Ga, and alterations at ∼1.73 Ga. Whole-rock chemical characteristics and Sm–Nd–Lu–Hf isotopes indicate that (1) The ∼2.52 Ga tonalites-trondhjemites-granodiorites were derived from partial melting of juvenile mafic crust; (2) the ∼2.51 Ga sanukitoid monzodiorite-granodiorite series came from slab-mantle interaction with different melt/rock ratios; (3) The ∼2.50–2.47 Ga potassic granites were generated by intracrustal recycling of metagreywacks that sourced from the mixture between juvenile and ancient crustal materials; and (4) The ∼2.50 Ga quartz syenites were originated from fractional crystallization of mantle-derived magmas. These petrogenetic processes reveal that the subduction-related crust-mantle interaction is the key reason for the diversity of late Neoarchean granitoids in the Dantazi Complex. Regional comparison indicates that the Precambrian North Hebei Terrane show distinct structure in the chronology and lithological assemblages from other basement terranes in the trans-North China Orogen and Western Block, implying that they were formed in different crust-mantle dynamic systems. Therefore, the Precambrian North Hebei Terrane was probably an independent micro-continental block at least until the early Paleoproterozoic. In the Archean crystalline basement range of the North Hebei–West Liaoning–East Hebei, from NW to SE, the magmatic crystallization ages gradually became older, and the granitoid assemblages transformed from sodium-rich to potassium-rich, the spatio-temporal evolution of chemical composition and lithological assemblages further indicates that the North Hebei Terrane was most likely developed in an arc environment with continuous retreat subduction caused by the slab roll-back. [ABSTRACT FROM AUTHOR]

• New in situ detrital zircon analyses are reported for the Winnipeg River terrane. • Eo-Paleoarchean detrital ages and their Hf compositions suggest local sources. • The Eo-Paleoarchean data overlaps with two other terranes in the Superior Province. • These three terranes may have comprised a once contiguous proto-cratonic nucleus. Metasedimentary rocks within Archean cratons can preserve a record of early cratonic crustal evolution and later metamorphic events. However, interpreting this record is difficult where the metasedimentary rocks have undergone amphibolite-granulite facies metamorphic overprinting and migmatization. In the Western Superior Province, migmatitic metasedimentary rocks represent a dominant supracrustal component in several terranes, including, from north to south, the English River, Winnipeg River, Wabigoon and Quetico terranes. Here we present zircon U-Pb-Hf isotope data for three metasedimentary rocks and one augen gneiss from the Mystery Lake dome in the Winnipeg River plutonic-gneiss terrane using in-situ techniques and large zircon populations. The augen gneiss contains zircon that has overlapping U-Pb-Hf isotope systematics with the ca. 3250 Ma gneissic basement of the terrane. The detrital zircon grains from the metasedimentary rocks have age populations at ca. 3750 Ma, 3600 Ma, 3500 Ma, 3400 Ma, 3300–3100 Ma, 3050 Ma, 2950–2900 Ma, 2850–2800 Ma, and 2800–2745 Ma, with metamorphic zircon between approximately 2745 Ma and 2550 Ma. The paucity of exposed Eo-Paleoarchean rocks in adjacent terranes suggests that the source rocks were derived from within the Winnipeg River terrane. The age and Hf isotope systematics of Eo-Paleoarchean detrital zircons from the Winnipeg River terrane overlap with zircon data from the Hudson Bay and Minnesota River Valley terranes on the northern and southern margins of the craton, respectively. The evidence suggests all three plutonic-gneiss terranes have preserved similar Eo-Paleoarchean geological histories, supporting the hypothesis that they were derived from a contiguous proto-craton. [ABSTRACT FROM AUTHOR]

• There are abundant carbonate clasts in the terminal Cryogenian Nantuo Formation. • These clasts were thought to have derived from Mesoproterozoic Shennongjia Group. • Petrographic and C-O isotope data are inconsistent with a Shennongjia Group source. • These clasts are likely from the Wujiatai Formation or a now eroded carbonate unit. Glacial diamictites of the Cryogenian Nantuo Formation of the Yangtze Craton of South China record major environmental transitions during the Marinoan glaciation. Although the provenance of the siliciclastic materials in the Nantuo Formation have been constrained via detrital zircon analysis, the source areas for the abundant carbonate clasts within the formation have yet to be determined. Given that the Mesoproterozoic Shennongjia Group is the only major extant pre-Cryogenian sedimentary carbonate succession in South China, it has been proposed as a source of the Nantuo dolostone clasts in the northern Yangtze Craton and may have been a major supplier of Cryogenian carbonate clasts across the entire Yangtze Craton, but this speculative provenance has not been tested or formally investigated. To test this hypothesis, δ13C and δ18O values of 18 clasts collected near Yichang, Hubei Province were analyzed along with petrographic examination to determine lithology, diagenetic alteration, and relationship to the Shennongjia Group carbonates. Our data show that the δ18O and δ13C values of these clasts are distinct from and thus unlikely sourced from the Shennongjia Group. Therefore, the Shennongjia Group cannot be the sole source of Nantuo carbonate clasts. Instead, we propose the Nantuo carbonate clasts in the study area were derived from either (1) pre-Marinoan carbonate successions in South China that were lost due to erosion or (2) another craton (e.g., the Indian Craton) adjacent to the Yangtze Craton during the Cryogenian. Given that paleogeographic and detrital zircon provenance analysis suggest separation between the Yangtze Craton and the Indian Craton in the Cryogenian Period, we favor the former origin, and that the Shennongjia Group is not the exclusive source of carbonate clasts from the Nantuo Formation. [ABSTRACT FROM AUTHOR]

Introduction: The Rochechouart impact structure in the NW part of the French Massif Central (FMC) is characterized by deep erosion that, however, still allows the recognition of a complete suite of impact lithologies, the crater floor, and various target lithologies (e.g., [1]). We present the first results from a project that is aimed at U-Pb on zircon isotope analysis of a representative set of surface and core samples of impact melt rocks and basement lithologies. These results will help to constrain the age of the impact event and provide information about the dynamics of the impact melt formation process in terms of the protolith target rocks for the diverse impact melt rock types. The analysis of the basement samples will improve and complement the current understanding of the FMC evolution in the region of the impact structure. Methodology: Zircons from a reddish impact melt rock from Montoume, a yellow impact melt rock from Recoudert, an amphibolite from Exideuil, and a gray foliated gneiss from Moulin de Laurière have so far been analyzed for U-Pb isotope data with a Neptune Plus Thermo Finnigan LA-MC-ICP-MS coupled with a Photon-Machines 193 nm laser system at the Laboratory of Isotope Geochemistry at the University of Ouro Preto, Brazil. Results: The oldest ages registered in zircons from both basement rocks are Neoproterozoic. The youngest ages from zircons of the gneiss are Silurian (433 ± 15 Ma), and from zircons of the amphibolite we obtained Carboniferous ages (326 ± 5 Ma). The principal age peak recorded from the basement zircons is at ~362 Ma, registered in the amphibolite. Other minor basement age peaks are registered at ~327 and ~449 Ma for the amphibolite; and ~523 Ma and ~544 Ma for the gneiss. The impact melt rocks display a greater variety of ages, from the Neoproterozoic to the Triassic (203 ± 2 Ma) for the Recoudert sample, and from the Neoproterozoic to the Lower Jurassic (195 ± 3 Ma) for the Montoume impact melt rock. The most prominent age peak registered in these impactites is at ~388 Ma and is from the Montoume sample. The Permian ages are obtained principally from the Recoudert sample. Discussion: The basement ages obtained in this study can be broadly correlated with different events of the evolution of the FMC (e.g., [2] and referred therein). Pre-Ordovician ages are probably related to protolith ages of the metamorphic basement. The ~362 Ma age peak is slightly older than the Variscan collision period, and similar ages have been obtained elsewhere in the NW FMC [3]. The ~327 Ma age is probably related to the Carboniferous exhumation period. The most prominent basement age peaks are not registered in the zircons from the two impact melts. Furthermore, these impactites display age peaks that are not found for the basement rocks analyzed to date. This is probably a result of different target rock lithologies involved in the formation of both impact melt rock samples. The age peaks observed for the impact melt rocks possibly record the exhumation of high-grade rocks at ~388 Ma [4] and a Permian granitization phase [5]. Finally, ~204 Ma ages recorded in zircon from both impact melt rocks are in agreement with recent U-Pb estimations of the age of the impact event (204 ± 2.2 and 207 ± 3.6 Ma; [5]). The youngest ~194 Ma ages obtained for the Montoume sample are similar to ~195 Ma ages previously reported for Babaudus impact melt rock [5]. Further textural characterization of these zircons will help in the interpretation of this apparent post-impact age. Conclusions: U-Pb age data for zircon from an amphibolite and a gneiss from the basement of the Rochechouart impact structure show good agreement with known events in the evolution of the FMC. Impact melt rock samples from Montoume and Recoudert show a great diversity of ages, including age peaks not recorded in the basement lithologies analyzed to date, which probably relates to target rocks that still need to be analyzed. Furthermore, the age of the impact event and a younger Lower Jurassic age were obtained. [ABSTRACT FROM AUTHOR]

Introduction: The ~31-km-wide Hiawatha structure, located beneath Hiawatha Glacier in northwestern Greenland, has been proposed as an impact structure that may have formed after the Pleistocene inception of the Greenland Ice Sheet [1]. However, available age constraints for the Hiawatha structure have only been tentative. The bedrock under the structure is likely a continuation of the highly metamorphosed 1.95-1.75 Ga [2] bedrock exposed immediately adjacent to Hiawatha Glacier, providing a maximum constraint on the structure's age [1]. Further age estimates have been based on indirect constraints, such as estimates of erosion rates and the structure's relationship to the Greenland Ice Sheet [1]. Here we dated the structure using detrital materials sampled immediately downstream thereof. We report 40Ar/39Ar analyses of impact-related glaciofluvial sand collected in 2016 and U-Pb analyses of shocked zircon from pebble-sized glaciofluvial clasts of impact melt rock collected in 2019. Results: Of the 50 grains that underwent 40Ar/39Ar step-heating analysis, 29 developed 'U'- or 'saddle'-shaped age spectra, with 23 giving minimum apparent ages in the Paleocene. Two mini-plateaus gave Late Paleocene ages of 58.5 ± 0.3 Ma and 60.2 ± 0.5 Ma, respectively. The 62 U-Pb analysis performed on 43 zircon grains using secondary ion mass spectrometry (SIMS) defined a discordant array in concordia space, spreading between an upper intercept of ~1915 Ma and a Late Paleocene lower intercept. The ~1915 Ma age for the majority of unshocked zircon grains from the impact melt rocks agrees with known geological events and zircon ages from the bedrock adjacent to Hiawatha Glacier [2], supporting a local origin for the samples. Of the 45 analyses performed on shocked zircon grains, the youngest nine data points are statistically indistinguishable, giving a robust concordia age and a weighted mean 206Pb/238U age of 57.99 ± 0.54 Ma (MSWD = 1.18; probability = 0.30; n = 9). We consider this to be the most robust estimate for the age of the impact structure [3]. Discussion: Impact melt rocks collected less than 10 km downstream from the edge of the Hiawatha structure contain unshocked zircon with ages matching that of the bedrock adjacent to Hiawatha Glacier. Shocked zircon in these samples gives a ~58 Ma U-Pb age, which agrees with the younger of two 40Ar/39Ar mini-plateau ages from the sand sample. The samples were thus derived from a Late Paleocene impact structure somewhere upstream but sufficiently proximal that the target geology is indistinguishable geochronologically from that exposed where the samples were recovered. Given existing geomorphic evidence for an eroded complex impact structure beneath Hiawatha Glacier, we suggest this is the source of the samples and thus that the Hiawatha structure is a relatively large impact structure that formed in the Late Paleocene. The new age indicates that the Hiawatha impact structure significantly predates Pleistocene glaciation and is unrelated to either the Paleocene-Eocene Thermal Maximum or flood basalt volcanism in east Greenland. The impact was contemporaneous with the Paleocene Carbon Isotope Maximum, although the impact's exact paleoenvironmental and climatic significance await further investigation. [ABSTRACT FROM AUTHOR]

• IN-SIMS zircon analysis yields a ca. 2.1 Ga age for Chipman and Kazan dike swarms. • Geochemical data suggests an asthenospheric-source for the STZ LIP swarms. • The STZ LIP underwent contamination by Neoarchean metasomatized lithosphere. • New data indicate that STZ dike swarms may be 2.1 Ga, and extend for > 800 km. • The STZ LIP formed during incipient rifting of a coherent Rae-Hearne boundary. • The STZ was reactivated during Hudsonian orogenesis from 1.98 to 1.80 Ga. IN-SIMS (in-situ secondary ionization mass spectrometry) micro-zircon geochronology resolves the age of the Chipman and Kazan mafic dike swarms exposed along the central segment of the Snowbird Tectonic Zone (STZ), the geophysically defined feature separating the Rae and Hearne subprovinces of the western Churchill Province. Long-considered syn -kinematic with respect to Paleoproterozoic transpressional deformation, the primitive composition of the STZ Large Igneous Province (LIP) and granulite grade metamorphic overprint has made establishing crystallization ages difficult. In-situ U-Pb isotopic analysis of micro-zircon yielded scattered and discordant results, except for four zircon crystals, which yielded a weighted mean of 2113 Ma +/- 22 (n = 8 analyses; MSWD: 0.46). This age is similar to other mafic complexes in the western Churchill Province including the Griffin Gabbro sills interpreted to have formed during opening of the Manikewan Ocean. Nd isotopic analyses of Kazan dikes paired with geochemical data suggest that the Chipman and Kazan dikes were asthenospherically-derived but contaminated by a metasomatized lithospheric root. At ca. 2.1 Ga, the STZ was the site of intracratonic extension within a coherent Rae-Hearne crustal block (Snowbird LIP Phase I). Existing data suggests that subsequent tectonism led to focused dextral transpression along the trace of the dike swarm and attests to a long-lived interplay of preexisting weaknesses and deformation. [ABSTRACT FROM AUTHOR]

• Meta-mafic rocks in this study experienced multiple metamorphism of the late Neoarchean and the late Paleoproterozoic. • The garnet-bearing mineral assemblages were formed during the late Paleoproterozoic rather than the Neoarchean. • The Neoarchean metamorphic event of Jiaobei terrane occurred in garnet-absent low pressure P-T conditions. Interpretations of high-grade terranes recording more than one episode of metamorphism can often be problematic due to the difficulties in assigning the metamorphic conditions to the time of metamorphism. The Jiaobei terrane as a typical Precambrian metamorphic terrane in the North China Craton (NCC) records multiple high-grade metamorphic events. Resolving the timing and features of each metamorphic event can cast light on the above issue and also play a key role in understanding the geological evolution of the Jiaobei terrane and the NCC. This study reports paired U-Pb dating with in-situ trace elements and oxygen isotope compositions of metamorphic zircons in meta -mafic rocks from the Qixia area of Jiaobei terrane. The zircons develop core-rim structures with both of them exhibiting metamorphic features. Zircon rims, although widely developed, are mostly too thin for in-situ age dating. LA-ICPMS as well as SIMS zircon U-Pb analysis of zircon cores yielded metamorphic ages of ∼ 2500 Ma, whereas the rims yielded 207Pb/206Pb ages of 1915–1717 Ma. The rare earth elements (REE) patterns and δ18O values measured in the Paleoproterozoic metamorphic zircon rims are distinct from those measured in the Archean cores. Distinct features of the cores and rims imply that the garnet-bearing (high-pressure) mineral assemblages were formed during late Paleoproterozoic metamorphic event and absent during the Neoarchean event. These new geochronological data further confirm that the Jiaobei terrane records both the late Neoarchean metamorphism and the late Paleoproterozoic tectonic thermal event. Also, our study argues for the existence of global subduction network geological records in the NCC during Paleoproterozoic, rather than during Neoarchean. The influence of the overprinted late Paleoproterozoic metamorphism should be fully considered when estimating P-T conditions of the earlier tectonothermal event (Neoarchean metamorphism). [ABSTRACT FROM AUTHOR]

• Detrital zircon age spectra analyses suggest that the Quanji Group and the overlying Neoproterozoic rocks in the OLT may have different source provenances. • The Great Unconformity in the OLT and NCC consists of two or three discrete unconformities. • These unconformities may have been caused by multiple tectonic activities rather than a single, global synchronous one. The Great Unconformity that separates the early Cambrian sandstones from the Proterozoic metamorphosed sedimentary rocks has been recognized in many blocks on Earth. However, whether it represents a globally synchronous event or a composite of a series of diachronous events, and its formation mechanism remain largely unknown. In this study, we carry out detrital zircon U-Pb analyses for seven samples collected from the Paleoproterozoic Quanji Group and the overlying Neoproterozoic strata in the Olongbuluke terrane (OLT) of Northwest China. The results show that apart from age populations of ∼ 1.8–2.0 Ga and ∼ 2.2–2.5 Ga for all samples, additional ∼ 1.55–1.65 Ga age population occurs in sample from the Zhoujieshan Formation, and more scattered age populations ranging from ∼ 0.75 to ∼ 1.7 Ga are present in samples from the Heitupo and Hongtiegou formations. The ∼ 1.8–2.0 Ga and ∼ 2.2–2.5 Ga zircons correlate well with the magmatic and metamorphic events in the OLT basement, indicating their local provenances, while other zircons were possibly derived from the North China craton (NCC) or other adjacent blocks. Combined with published paleontological, stratigraphic, and geochronological data, the present study supports previous inference that the OLT had a close paleogeographic affinity to the NCC during late Paleoproterozoic to Neoproterozoic. New zircon U-Pb ages indicate that the Heitupo Formation was deposited later than ∼ 750 Ma, and the underlying Hongzaoshan Formation was deposited at ∼ 1.66 Ga, implying a huge break between them. Whereas the duration of the sedimentary break between the Heitupo Formation and the overlying Hongtiegou Formation is uncertain, biostratigraphic data suggest that a break of ∼ 30 Myr may exist between the late Ediacaran Zhoujieshan Formation and the overlying early Cambrian Xiaogaolu Group. The occurrences of these multiple unconformities in OLT are comparable to those in NCC, indicating that the Great Unconformity is represented by a series of lengthy denudations during the Proterozoic-early Cambrian in both the OLT and NCC, which may result from multiple tectonic activities in these two blocks. [ABSTRACT FROM AUTHOR]

[Display omitted] • Collapsed breccia zone associated with normal faulting is found in the Taihang Shan. • Allochthons in the Taihang Shan were formed by basal detachment in NW-SE extension. • Upper-crustal extensional deformation occurred in the Taihang Shan at ∼134 Ma. • The Taihang Shan experienced crustal extension like the Eastern Block during NCC destruction. Whilst geophysical exploration and petrological analyses imply that the Early Cretaceous North China Craton (NCC) destruction may have impacted the Taihang Shan in the central NCC, associated evidence indicative of contemporary upper-crustal extension is lacking. We herein investigate the formation mechanism and timing of the allochthons that consist of Mesoproterozoic to Mesozoic sedimentary rocks within the Paleoproterozoic Fuping complex in the middle Taihang Shan, based on field investigation and zircon U-Pb analysis. Our results indicate that the western boundary of the selected allochthon features wide collapsed breccias filled with synchronous Early Cretaceous (∼134 Ma) pyroclastics. These allochthons likely formed under extension along with the basement doming of the Fuping complex in response to crustal stretching in Early Cretaceous. Our results provide explicit evidence of upper-crustal extension in the Taihang Shan associated with the Early Cretaceous NCC destruction. [ABSTRACT FROM AUTHOR]

• Abundant zircon xenocrysts were captured by the late Paleozoic (<342 Ma) Maping diamondiferous kimberlites. • Xenocrystic zircon peak ages at ∼2.9 Ga, ∼2.6 Ga and ∼2.0 Ga are older than the Neoproterozoic outcrops. • Highly evolved Archean basement may exist beneath the southern Yangtze Block. • The basement underwent complex crustal growth at 2.6–2.5 Ga and reworking at 3.0–2.6 Ga. • Newly identified ∼2.0 Ga metamorphic event was probably linked to the assembly of the Nuna/Columbia supercontinent. Crustal zircon xenocrysts from mantle-derived magmatic rocks have the potential to probe the deep crust. Here we present integrated U–Pb dating and Hf-isotope analyses of zircons from a Paleozoic diamondiferous kimberlite dike in the Maping area of Zhenyuan County (southeastern Guizhou Province), with implications for the tectonothermal evolution of unexposed continental crust beneath the southern Yangtze Block, South China. All zircons (n = 236) show a wide range of U–Pb ages between Mesoarchean and middle Carboniferous. Among them, 96 zircons with 90–110% concordance yield concordant ages from 2942 ± 8 Ma to 342 ± 2 Ma, and form major age peaks at ∼2.9 Ga, ∼2.6 Ga and ∼2.0 Ga. The overwhelming majority of zircons are dominated by Mesoarchean–Paleoproterozoic U–Pb ages regardless of their concordance degrees. The zircon populations mainly consist of magmatic zircons, with minor metamorphic grains (Th/U < 0.10). The youngest magmatic zircon (Th/U = 0.43) with a well concordant 206Pb/238U age of 342 ± 2 Ma (M1-16) is interpreted as the maximum emplacement age of the Maping diamondiferous kimberlites. Most zircons with pre-eruption ages are considered to be xenocrysts, and they may be derived from the deep-seated continental crust through which kimberlite host magmas have passed. Their U–Pb ages and Hf isotopic compositions suggest the possible existence of a highly evolved Archean basement beneath the southern Yangtze Block, South China, which is much older than its known surface rocks. A lot of magmatic zircon xenocrysts reveal complex Precambrian crustal evolution in the southern Yangtze Block. These processes involved the important growth of continental crust at 2.6–2.5 Ga, and in the meantime, crustal reworking could be intermittently proceeding at 3.0–2.6 Ga. In addition, a group of xenocrystic zircons are identified to be of metamorphic origin, indicating that the proposed Archean basement beneath the southern Yangtze Block likely experienced a metamorphic event around 2.0 Ga. This geologically significant episode is consistent with the well-developed coeval metamorphism in other places of the Yangtze Block (e.g., Kongling Terrane), which has been considered to link to the assembly of the Paleoproterozoic Nuna/Columbia supercontinent. Our zircon data implies that the unexposed Archean basement beneath the southern Yangtze Block was affected by multiple thermal activities. [ABSTRACT FROM AUTHOR]

The Baoshan, Tengchong, Lhasa, South Qiangtang, and Sibumasu terranes were part of Gondwana prior to rifting and drifting from the northern margin since the Early Permian. However, paleopositions of these terranes during the late Paleozoic remain controversial, which hinders better understanding the tectonic evolution of the Paleo-Tethys and glacier distribution patterns on eastern Gondwana during the late Paleozoic ice age. As robust provenance indicators, detrital zircon U–Pb dating and Hf isotope signatures have been widely utilized in paleogeographic reconstruction. Here, we collected a total of 8209 detrital zircon U–Pb ages and 1606 zircon Hf isotopic values from Paleozoic strata of northeastern Gondwana. These data are utilized to evaluate their paleopositions relative to Australian and Indian Gondwana through semi-quantitative data analysis. Our new paleogeographic model indicates that the South Qiangtang, Baoshan, and part of Sibumasu were outboard of the northern margin of Indian Gondwana during the Paleozoic, whereas the Lhasa and Sumatra terranes were located along the northern margin of Australia. Based on provenance shifts of late Paleozoic glaciogenic sedimentary rocks in northeastern Gondwana, two main ice sheets are hypothesized to have developed during the late Paleozoic. This study further confirms the model of a multicenter glacier distribution pattern on Gondwana during the late Paleozoic ice age from a perspective of provenance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Limpopo Belt Central Zone consists of two terranes (T1, T2) of distinct origin. • T1 was connected to the Zimbabwe Craton between 3.4 and < 2.9 Ga as indicated by detrital zircons. • T2 comprises an oceanic realm < 3.05 Ga which became successively accreted to the Kaapvaal Craton. • Final closure of the oceanic realm resulted in T1-Zimbabwe-Kaapvaal Craton collision at 2.62 Ga. • Post-collisional sandstones of the Central Zone and Kaapvaal Craton have different provenances. There are ongoing debates about the nature and timing of Kaapvaal-Zimbabwe Craton accretion. A critical role in this discussion plays the Central Zone (CZ) of the Limpopo Belt, which represents a polymetamorphic gneiss terrane limited by the Kaapvaal Craton to the South and the Zimbabwe Craton to the North. Uncertainties mainly result from complex field relationships, the lack of age data, and the complexity of investigated zircon grains. In this study we present new results of combined U-Th-Pb and Lu-Hf isotope analyses of zircon grains from quartzite, granitoid, and metabasite samples from different areas of the CZ. These data indicate that the oldest lithologies are mafic rocks which were emplaced at 3.35–3.29 Ga from near-chondritic mantle source. They also reveal that quartzite precursors throughout the CZ were deposited during two major sedimentary cycles, with quartzite-I members between 3.36 and 2.64 Ga, and quartzite-II between 2.55 and 2.04 Ga, and that the detritus was supplied from distinct sources. Detrital zircon grains of quartzite-I were delivered from Eo- to Mesoarchean granite-gneiss terranes, affected by magmatism between 3.92 and 2.90 Ga, and characterized by hafnium model ages (T DM) between 4.40 and 3.30 Ga. In contrast, zircon grains of quartzite-II stem predominately from Neoarchean granitoids, which intruded between 2.73 and 2.62 Ga, and mostly show T DM of 2.88 ± 0.06 Ga (n = 8) or 3.09 ± 0.10 Ga (n = 4). Comparison with published age-εHf t data and spatial relationships suggest quartzite-I being sourced mainly from the Zimbabwe Craton, which was connected to parts of the CZ since the Paleoarchean, and quartzite-II from granitoids of an independent Neoarchean terrane (with T DM 3.1–2.9 Ga), which was derived from the same mantle source as the crust of the adjacent Pietersburg Block (northern Kaapvaal Craton). All data in combination provide evidence that the CZ of the Limpopo Belt hosts a composite terrane that comprises relics of (1) Zimbabwe Craton-related crust, and (2) a south-to-north developing accretionary system of granite-greenstone terranes younger than 3.1 Ga, which finally collided with the Zimbabwe Craton at ca. 2.62 Ga. [ABSTRACT FROM AUTHOR]

[Display omitted] • In-situ Sr-Nd-O isotopic analyses of minerals are employed to constrain the nature of primary magmas in the Weishan syenite-(carbonatite) complex. • Both lithospheric and asthenospheric mantle have contributed to the generation of the Weishan complex. • Involvement of asthenosphere-derived components may play an important role in the enrichment of REE in the Weishan complex. Carbonatite-alkaline complexes are commonly derived from the mantle. However, whether the source is lithospheric or asthenospheric mantle remains debated. In order to better understand this issue, this paper conducts a Sr-Nd-O isotopic study on the Early Cretaceous, Weishan REE-rich syenite-(carbonatite) complex, Northern China. Two types of apatite are identified from the Weishan complex, namely magmatic and xenocrystic apatite. In-situ Sr-Nd isotopic analyses on magmatic apatite yielded (87Sr/86Sr) i from 0.70690 to 0.70719, and ε Nd (t) from −7.6 to −8.8. The pristine calcite from carbonatite has similar (87Sr/86Sr) i (0.70727–0.70739) with magmatic apatite. In-situ oxygen isotopic analyses on zircon yielded δ18O VSMOW (‰) from 5.9 to 6.7 ‰. Previous studies reveal that coeval, mantle lithosphere-derived rocks in the region have more enriched Sr (87Sr/86Sr i greater than 0.709) and Nd [ε Nd (t) 〈 −1 2] isotopes than the Weishan complex; whereas the asthenosphere-derived rocks in the region are characterized by depleted Sr-Nd isotopes (87Sr/86Sr i < 0.706; ε Nd (t) greater than 0) and low δ18O VSMOW values (mostly < 5.4 ‰). It is well known that Northern China experienced destruction in the Early Mesozoic, which was accompanied with asthenosphere upwelling along trans -lithosphere faults. Considering that the Weishan complex locates adjacent to the trans -lithosphere Tanlu fault, generation of the complex may be related to asthenosphere-lithosphere interaction. Notably, the Weishan complex differs from coeval REE-barren carbonatites in that its source involved asthenosphere-derived components; hence, involvement of asthenosphere-derived components may be important for the formation of such a REE-rich complex. In general, this study highlights the importance of lithosphere-asthenosphere interaction in supplying necessary heat and materials for the generation of the Weishan complex. [ABSTRACT FROM AUTHOR]

Sedimentary basins with epiclastic and volcanoclastic components are important geotectonic components for understanding the complex evolution of orogenic systems. The age, provenance and tectonic setting of ancient basins are, however, often hard to constrain, especially in the high-grade core of ancient mountain belts where original sedimentary and stratigraphic relations have been largely obliterated by deformation and metamorphism. In this case, analytical tools such as whole-rock geochemistry and U–Pb and Lu–Hf analyses on detrital zircon grains can be deployed to unravel the provenance and tectonic setting of high-grade metasedimentary and metavolcaniclastic units. Here, we apply these analytical tools on samples from gneissic paleosomes of migmatites found in the eastern transition zone between the Neoproterozoic–Eopaleozoic Araçuaí and Ribeira orogens (southeastern Brazil). The studied paleosomes comprise peraluminous paragneiss rich in biotite, garnet and sillimanite, metaluminous hornblende-bearing gneiss free of peraluminous silicates, and intermediate terms between these compositions, all of them with geochemical characteristics pointing to sources located in magmatic arc systems. Overall, U–Pb data from detrital zircon grains bracket a maximum sedimentation age for all samples between 600 and 627 Ma, while εHf (t) : +5.7 to −18.7 and Hf T DM model ages of 1.0–2.2 Ga suggest moderately juvenile to evolved sources for the gneiss protoliths. However, despite the similarity in age range, the analyzed samples show contrasting isotope data indicating significant variability in the source areas. Sample 7 only has grains with negative εHf (−5.9 to −18.7), most of them ranging in age from 708 Ma to 758 Ma, with very few older (1021–1143 Ma) and younger (642–651 Ma) zircons grains, indicating evolved crustal sources of distinct ages (e.g., the Late Tonian – Early Cryogenian South Bahia Alkaline Province, the Early Cryogenian magmatism found in the West Congo Belt, the Stenian to Early Tonian Espinhaço and Matadi-Noqui igneous rocks, and magmatic rocks of the early Rio Doce arc). Conversely, sample 13 has twenty grains with positive εHf values and ages between 602 and 758 Ma, suggesting sourcing from (meta)igneous rocks of the Rio Negro arc and their remelting products, and forty grains with negative εHf values with ages between 591 and 646 Ma suggesting magmatic sources in the Rio Doce arc. Additionally, the two youngest spot ages (553 Ma and 571 Ma) have highly negative εHf values (−11.1 and −16.4) suggesting their origin from collisional anatexis. Similarly, sample 12 shows detrital grains within the consistent time interval (ca. 596 Ma – 798 Ma) of the Rio Negro arc and Rio Doce arcs, reinforcing that the fragments of these arcs, or zircons that were inherited from these terranes, are potential sources to the sedimentary protoliths of the paragneisses. The regional scenario together with our field and analytical data, compared with data available in the literature, suggest the sedimentary protoliths of the studied samples filled orogenic basins related to the Rio Doce magmatic arc. Most detrital zircon ages are close to the maximum depositional age, a classical signature of orogenic basins related to magmatic arcs. The studied paragneiss unit correlates with the Nova Venécia Complex, located on the intra-arc to back-arc zones of the Araçuaí orogen, and with the orogenic succession of the distal Andrelândia Group, shared by both the Araçuaí and Ribeira orogens. Furthermore, our data also suggest the juvenile Rio Negro - Serra da Prata arc system was either amalgamated with the Rio Doce arc or that fragments of these arcs were incorporated as unmelted xenoliths and xenocrystals within the Rio Doce arc rocks before ca. 614 Ma, providing key hints to unravel the evolution of the Araçuaí - Ribeira orogenic system (AROS) and its role in the Gondwana assembly. • Paragneisses from the Araçuaí-Ribeira Orogen sourced from Ediacaran arcs. • Maximum sedimentation age for all samples between 600 and 627 Ma. • Moderately juvenile to evolved sources (εHf (t) : +5.7 to −18.7, T DM = 1.0–2.2 Ga). • Elemental geochemistry coherent with graywackes from active margin settings. • Syn-orogenic basins related to the Rio Doce (G1 Supersuite) continental-margin arc. [ABSTRACT FROM AUTHOR]

The Cerro Uyarani Metamorphic Complex (CUMC) in Bolivia provides a record of complex Paleoproterozoic to Mesoproterozoic tectono-magmatic evolution, as revealed through U–Pb isotopic analysis of zircon from three litho-domains (DI – DIII). The Paleoproterozoic crystalline basement was subject to two stages of Mesoproterozoic reworking. This detailed study of zircon textures and geochronology, including determination of first Hf-isotope data, from felsic granulites, banded granulites and amphibolites reveals a first Paleoproterozoic event at 1.81–1.74 Ga in magmatic and some metamorphic zircon cores, with zircon ϵHf T values of +6.3 to −0.2. A subsequent Mesoproterozoic event can be divided into 2 cycles: a first one at 1.19–1.17 Ga is reflected by recrystallized rims and cores of zircon with ϵHf T values of −6.8 to −3.6. This cycle is here associated with migmatization of the basement, during which the Paleoproterozoic crust was differentiated into DI-leucosome rich migmatite, DII-leucosome rich migmatite, DIII – our best proxy of Paleoproterozoic crust, melanosome, and paleosome. The second cycle at ∼1.1–1.0 Ga is recorded in metamorphic rims and by newly grown metamorphic zircon with ϵHf T values of −15.1 to −2.6. This event was responsible for the transformation of the CUMC migmatitic basement into granulite facies rocks. We interpret that the CUMC was part of the southernmost portion of the Arequipa terrane from, at least, ∼1.74 Ga and that it then became attached to the Paraguá terrane and Amazon craton at 1.19–1.17 Ga. This collision generated migmatites, and then, with the arrival of Laurentia passing through the Arequipa terrane front (with CUMC at the Arequipa terrane), the conditions of metamorphism were raised to granulite facies. A younger event of lower metamorphic grade and likely associated with fluid-driven alteration is recognized in the partial retrograde transformation of mafic granulites into amphibolites. Our new U–Pb and εHf T data indicate that the Paleo-to Mesoproterozoic history of the CUMC is, thus, similar to that of the Arequipa terrane, Rio Apa terrane, the SW Amazon craton, and other Grenville-age inliers; but it was distinct from the evolution of the Sierra de Maz and Pie de Palo of the hypothetical MARA craton. • The Cerro Uyarani Metamorphic Complex (CUMC) witnessed multistage tectono-magmatic-metamorphic Paleo-to Mesoproterozoic events, similar with Arequipa terrane, Rio Apa terrane, SW of Amazon craton and Grenville inliers. • U–Pb and Hf-isotope data assign the first tectono-magmatic-metamorphic event with ages between 1.88 and 1.67 Ga. • Zircon textures indicate a second event distinguished by a first cycle of migmatization at ∼1.19 Ga and a second cycle of granulite metamorphism at 1.10–1.00 Ga; two reworking phases of Paleoproterozoic crust during the Mesoproterozoic. • U–Pb and Lu–Hf isotopic data reveals the association of the Cerro Uyarani Metamorphic Complex with the youngest events of the Grenville-Sunsas Orogeny. [ABSTRACT FROM AUTHOR]