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The Qinling‐Dabie‐Sulu orogen is the eastern part of the Central China Orogenic Belt. Looking back on previous studies of the sedimentary record we systematically compiled the dataset of detrital zircon U–Pb ages and Hf isotopes for this orogenic belt. The dataset incorporates a comprehensive compilation of 32,449 detrital zircon U–Pb ages and 979 Hf isotopes. The findings demonstrate that distinct tectonic units within the orogenic belt exhibit unique tectonic evolution histories during various geological epochs. This dataset can be used to constrain the tectonic framework and orogenic evolution including ocean subduction, continental collision and orogen exhumation. It can be integrated with other geological datasets to improve our understanding of the Central Orogenic Belt in China, and possibly plate tectonics globally. [ABSTRACT FROM AUTHOR]

Hydroclimate is an important factor controlling landscape evolution. But establishing the impact of hydroclimate is complicated by the influences of other processes and is especially hard to prove for those in deep time from geological record. During the late Permian, voluminous basaltic sediments were derived from the erosion of the Emeishan large igneous province in western South China. They provide a unique record critical in understanding the responses of tropical basaltic erosion to hydroclimate change without impacts of orogenic uplift, lithologic variation, vegetational difference and glacial‐interglacial change. Sampled successions define a negative carbon isotope excursion capable of making regional and global stratigraphic correlations in the middle Wuchiapingian interval corresponding to the final phase of the late Paleozoic ice age. This interval is associated with a petrofacies shift and a decreasing source weathering intensity, a downward shift of erosion loci, and a reduced coastal water paleosalinity. Applying present‐day temperature dependence pattern of basaltic weathering and using land surface temperatures approximated from nearby paleo‐seawaters, denudation rates were calculated for the Emeishan basaltic province and shows an increase from ∼71 to ∼107 m/Ma. This erosional acceleration is temporally correlated with a decrease in paleosalinity and likely linked to enhanced freshwater discharge in the middle Wuchiapingian. Scaling and landscape erosion modeling suggest ∼80%–130% increase in catchment precipitation could have driven this acceleration in denudation. Our work provides a positive test for the hydroclimate forcing on landscape erosion in deep time and underlines the mechanistic linkage of sediments with erosion and climate change. Plain Language Summary: Sedimentary records provide a unique way to track source weathering and erosion in the deep geological past. During the late Permian to early Triassic voluminous basaltic sediments were eroded from the Emeishan large igneous province, which was emplaced at ca. 260 Ma in southwestern China, into the adjacent basins. These late Permian sedimentary records are studied to understand the denudation of this tropical basalt province in the final period of the late Paleozoic ice age (LPIA). Our data reveal a negative organic carbon isotope excursion, decreasing weathering intensity and deepening erosional loci in the Emeishan basaltic province, and a reduced salinity due to greater rainfall in the middle Wuchiapingian interval. Denudation rate was estimated for the Emeishan province and a correlation of high denudation rates with lowered paleosalinity was documented in the Wuchiapingian. The accelerated denudation in the Emeishan basaltic province was ascribed to ∼80%–130% increase in catchment precipitation during the final phase of the late Paleozoic ice age. This work highlights the importance of sedimentary records to understand the deep time landscape evolution. Key Points: A negative carbon isotope excursion enables middle Wuchiapingian stratigraphic correlations from South China to GondwanaA decrease in weathering intensity and a deepening of erosional exhumation are indicated for the Emeishan basaltic provinceDenudation was accelerated due to ∼80%–130% increase in precipitation during the late Permian in SW China [ABSTRACT FROM AUTHOR]

Improvements in analytical technique and data processing lead to a large deposit of detrital zircon U–Pb and Hf isotopic data in published journal articles, thesis and reports. With the support of Deep‐time Digital Earth Big Science Program, OneSediment Project conducted a team‐working effort to assemble the detrital zircon U–Pb and Hf isotopic data for mainland China and adjacent regions. Entity‐relationship diagram was constructed for detrital zircon data to determine what information need to be collected. Researchers and students from 13 institutions were organized together to fulfil this task and generated 13 detrital zircon datasets. The assembled datasets totally include 6635 samples and 560,596 analyses. The samples were checked in terms of lithology and stratigraphy according to the latest stratigraphic framework. Collected detrital zircon U–Pb and Hf isotopic data were recalculated for the best U–Pb age and εHf(t) values. They can be used to track crustal growth, tectonic evolution, provenance analysis and palaeogeographical change in regional and, when combined with other dataset, global scales. [ABSTRACT FROM AUTHOR]

We analyzed the major and rare earth element compositions of siliceous deposits from the Upper Devonian Liujiang Formation, Lower Carboniferous Luzhai Formation, Lower–Middle Permian Sidazhai Formation and Tapi Formation, which are widely distributed as bedded cherts in the interplatform basinal successions of the Youjiang Basin. The Liujiang Formation and Luzhai Formation cherts generally have high Al/(Al+Fe+Mn) values (0.38–0.94) and are non-hydrothermal cherts. These cherts are generally characterized by moderately negative Ce anomalies and high Y/Ho values relatived to PAAS, indicating that the Youjiang Basin might have evolved into an open rift basin during the Late Devonian–Early Carboniferous. The Sidazhai Formation cherts from Ziyun generally have high Al/(Al+Fe+Mn) values (0.60–0.78), suggesting negligible contribution from a hydrothermal component. The Sidazhai Formation cherts from Hechi and the Tapi Formation cherts from Malipo generally have low Al/(Al+Fe+Mn) values (0.09–0.41), indicating an intense hydrothermal input. Relatived to the Sidazhai Formation cherts, the Tapi Formation cherts have higher Ce/Ce* values (0.68±0.19) and lower Y/Ho values (41.83±13.27), which may be affected by the terrigenous input from the Vietnam Block. The Sidazhai Formation cherts from Ziyun and Hechi exhibit negative Ce anomalies (0.43±0.12, 0.33±0.17, respectively) with high Y/Ho values (57.44±16.20, 46.02±4.27, respectively), resembling the geochemical characteristics of open-ocean basin cherts. These cherts were deposited on a passive continental margin adjacent to the Babu branch ocean, which may have contributed to upwelling. Detailed spatial studies on geochemical characteristics of the Late Paleozoic cherts can unravel the evolution of the Youjiang Basin.

The concentrations of redox-sensitive trace elements, such as uranium (U), vanadium (V), molybdenum (Mo), cobalt (Co), chromium (Cr) and rare earth elements (REE+Y) were determined in a given carbonate succession in the Gaoyuzhuang Formation (~1.56 Ga), which spans depths from outer shelf to intertidal, to explore the Early Mesoproterozoic ocean redox conditions. The values of the Zr-normalized redox-sensitive trace element concentrations and some relevant ratios show obvious changes from bottom to top in the succession. Samples from the outer shelf setting (M1 interval) demonstrate significantly enhanced values in Zr-normalized redox-sensitive trace element concentrations and relevant ratios (the peaks of Mo/U, V/Cr and Ni/Co ratios larger than 8, 4.25, and 7, respectively). Authigenic framboidal pyrites were also found within oncolite-like carbonate concretions and surrounding host rocks in this interval. These all indicate a euxinic state in the outer shelf environment. Less enrichment of Zr-normalized redox-sensitive elemental abundances and a mild decrease in the values of geochemical ratios were present in the inner shelf environment (M2 interval) (the V/Cr and Ni/Co ratios fall into a range of 2.5-4.25 and 4-5, respectively), suggesting dysoxic conditions dominant in the inner shelf setting. Samples from the shallower subtidal and intertidal settings (M3 and M4 intervals) are mostly invariable with much lower values of Zr-normalized redox-sensitive elements and relevant ratios, with the V/Cr and Ni/Co ratios typically near or less than 2 and 5 respectively, indicative of oxic conditions in the high-energy subtidal/intertidal zones. A remarkable negative Ce anomaly exhibited in the shale-normalized REE+Y diagram in the M4 interval may provide evidence in support of the hypothesis. Taken together, our results suggest a relatively shallow chemocline in the Early Mesoproterozoic ocean: the transitions between euxinic, dysoxic and oxic may occur in quiet-water outer shelf and highenergy subtidal zone, respectively. The presence of euxinic ocean bottom waters is compatible with low concentrations of seawater sulfate and reduced levels of atmospheric oxygen during this period. The extreme environmental conditions induced by these anoxic oceans could have been responsible for the delayed oxygenation of the biosphere and hindered the evolution of multicellular life.

In order to study the effect of device structures and silicon wafer positions on light-induced degradation (LID) and regeneration, five groups of industrial PERC and Al-BSF solar cells were fabricated by using silicon wafers from different positions of a B-doped Czochralski silicon (Cz-Si) ingot. Then, the cells were subjected to a dark annealing (200 °C, 30 min), the first LID (45 °C, 1 sun, 12 h), an electrical injection regeneration (175 °C, 18 A, 30 min) and the second LID (45 °C, 1 sun, 12 h) in order, and the variations of performance of the cells with processing time were measured. It was found that after the electrical injection regeneration, the efficiency losses of PERC cells decreased from 1.28–1.76%absolute in the first LID to 0.09–0.16%absolute in the second LID, while those of Al-BSF cells decreased from 0.3–0.66%absolute in the first LID to 0 in the second LID. The efficiency losses of PERC cells during the first LID were caused by the co-action of B-O-defect-induced LID (BO-LID) and dissociation of Fe-B pairs, and the latter contributed 5.81–9.56% of the efficiency loss, while those of Al-BSF cells during the first LID were almost contributed by BO-LID solely. For both kinds of cells, the cells made from the silicon wafers from middle of the ingot had the best performance throughout the experiment. In addition, the LID and regeneration treatments only affected the spectral response of the cells in the wavelength larger than 700 nm. [ABSTRACT FROM AUTHOR]

In this paper, five groups of industrial aluminium back-surface-field (Al-BSF) solar cells were made from silicon wafers from different locations of a B-doped Czochralski silicon ingot. Then, we performed the first LID (45 °C, 1 sun, 12 h), regeneration (100 °C, 1 sun, 24 h), and second LID (45 °C, 1 sun, 12 h) treatments on the cells, and measured the in-situ changes of their I-V characteristic parameters by using an I-V tester during the experiment. The cells were also characterized by Suns-Voc measurement, full-area light beam induced current scanning, and external quantum efficiency measurement at the four breakpoints of treatments (before and after the first LID, after regeneration and the second LID). It was found that the LID and regeneration of the Al-BSF solar cells can be explained by the LID and regeneration reaction of B-O defects and the LID caused by dissociation of Fe-B pairs. After regeneration, the relative decay rate of efficiency decreased from 2.75–3.8% during the first LID to 0.42–1.23% during the second LID, indicating that regeneration treatment (100 °C, 1 sun, 24 h) can improve the anti-LID ability of Al-BSF solar cells. [ABSTRACT FROM AUTHOR]

[1] The Huangshi foreland basin developed on the southern margin of the Dabie Mountains as a result of tectonic loading during Triassic collisional suturing between the North China and South China cratons. Modal and detrital zircon data for Jurassic samples within the basin suggest a multicomponent source with input from both the South China Craton and Dabie Orogen. Samples are predominantly quartz arenites derived, on the basis of framework compositions, from a recycled orogen source. Detrital zircons range in age from Archean to Triassic with a dominant component in the late Paleoproterozoic between 1.9-1.7 Ga and subsidiary components at 2.6-2.2 Ga, 0.8-0.7 Ga, 0.5-0.4 Ga, and 0.33-0.2 Ga. Age data integrated with cathodoluminescence and trace element data for the zircons indicate that the Archean and Proterozoic detritus was derived from igneous and metamorphic sources that overlap with time-equivalent pulses of such activity within the South China Craton. Phanerozoic zircon ages overlap the times of the Ordovician, Carboniferous and Triassic high-pressure metamorphism in the Dabie Mountains. The provenance record, integrated with paleocurrent and regional relations, enables a paleogeographic reconstruction in which the Huangshi Basin was fed by a major axial flowing trunk river system carrying detritus from eastern and southern sources within the South China Craton and was also fed by short south flowing tributaries supplying some detritus from the evolving Dabie Orogen. The dominance of cratonic-derived detritus within the provenance record of the Huangshi Basin contrasts with that of the Hefei foreland basin that lies to the north of the Dabie Mountains, which is dominated by Neoproterozoic - Mesozoic detritus derived directly from the Dabie Mountains and lacks any significant older Paleoproterozoic or Archean components. Easterly extensions of the Dabie-Sulu collisional suture and of the resultant Huangshi Basin occur in Korea and Japan over an along strike length of some 2000 km. Citation: Yang, J., P. A. Cawood, and Y. Du (2010), Detrital record of mountain building: Provenance of Jurassic foreland basin to the Dabie Mountains, Tectonics, 29, TC4011, doi: 10.1029/2009TC002600.

The 87Sr/86Sr minimum of the Capitanian seawater is one of the most significant features in the Phanerozoic seawater 87Sr/86Sr history. In order to assess possible contribution of the Emeishan large igneous provinces (LIPs) to strontium isotope evolution of the Capitanian seawater, 87Sr/86Sr ratios were measured from the Capitanian limestones which are locally interlayered with the Emeishan basalts. The limestones underlying the Emeishan basalts have high 87Sr/86Sr ratios (0.7070–0.7074). However, extremely low 87Sr/86Sr ratios (0.7068–0.7070) were identified in the late Capitanian Jinogondolella prexuanhanensis–J. xuanhanensis zones, which correspond to the eruption time of the Emeishan LIP. The temporal coincidence of these two phenomena supports the idea of a potential linkage between Capitanian 87Sr/86Sr minimum and eruption of this igneous province. The strong submarine hydrothermal activity and erosion of the Emeishan LIP could have released large amounts of non-radiogenic Sr to the oceans and play an important role in strontium isotope evolution of the seawater. [ABSTRACT FROM AUTHOR]

The last glaciation during the late Paleozoic ice age commenced at around the Guadalupian–Lopingian (G–L) boundary and is synchronous with the emplacement of the Emeishan large igneous province. Using CA-TIMS zircon U–Pb dating, we obtained an age of 259.51 ± 0.21 Ma for the uppermost tuff from the Puan volcanic sequence in the eastern Emeishan large igneous province, constraining the timing of Emeishan volcanism and providing another candidate age for the G–L boundary. In addition, we determined an age of 259.69 ± 0.72 Ma for a basal claystone in the immediately overlying Longtan Formation from a drill core section in southwest South China. These ages, along with source weathering trends of mudstones from the lower Longtan Formation, and compiled paleotemperature records, indicate an earliest Wuchiapingian cooling coinciding with the onset of the last Permian glaciation. This global cooling is associated with positive shifts in both organic and carbonate carbon isotopic records and likely a decrease in atmospheric p CO 2 . A hypothesised causal linkage is proposed in which the rapid post-eruptive basaltic weathering of the Emeishan province in an equatorial humid belt may accelerate the atmospheric CO 2 consumption and lead to climate cooling. Our work supports the long-term climate cooling effects of large igneous provinces. [ABSTRACT FROM AUTHOR]

The article focuses on the significance of Deep-time Digital Earth (DDE) in the field of sedimentology for thematic databases.

The article focuses on the Deep-time Digital Earth Program (DDE) used to collect sedimentary data of the Earth.

The construction of databases of detrital zircon is important for Earth science research. A total of 27,915 U–Pb ages and 4,968 Hf isotopic compositions of detrital zircons from the upper Paleozoic–Mesozoic strata of the North China Block were compiled from articles in the Web of Science and the China National Knowledge Infrastructure. This dataset yields five age groups, at 3.9–1.0 Ga, 1,000–540 Ma, 540–360 Ma, 360–240 Ma and 240–95 Ma. The 3.9–1.0 Ga group has two peaks at ~2.5 and ~ 1.85 Ga. The 1,000–540 Ma and 540–380 Ma groups have three peaks at ~920 Ma, 780–750 Ma and ~ 440 Ma. Detrital zircon grains with ages of 360–240 Ma have multiple age peaks at ~380, ~320, ~280 and ~250 Ma. The group with ages of 240–95 Ma yields four peak ages at ~220, ~180, ~160 and ~120 Ma. Corresponding εHf(t) values range from −81.3 to +41.9, with two‐stage Hf model ages (TDM2) of 4,335–204 Ma. This dataset provides a comprehensive and systematic archive of detrital zircon data for Paleozoic–Mesozoic successions in the North China Block, which can be used to track tectono‐sedimentary and crustal evolution. In using this dataset, two issues need to be considered. First, the number of detrital zircon analyses from each sample varies markedly, which may influence the interpretation of the dataset. Second, there may be large uncertainties in the stratigraphic ages assigned to the samples. [ABSTRACT FROM AUTHOR]

The Early Paleozoic Lian-Shao Basin, South China, is a syn-orogenic basin that developed on the northern margin of Gondwana in response to the Kwangsian orogeny. U–Pb detrital zircon age patterns from Middle Ordovician to Lower Silurian sandstones around the Jiangnan Uplift within the basin provide evidence for exhumation and erosion of the basin basement. The majority of the samples from both east and west of the Jiangnan Uplift display similar age distributions with a dominant peak between 1000 and 900 Ma and subordinate peaks at ~ 2500 Ma, ~ 1700 Ma and 600–500 Ma. However, the zircon age spectrum of one sample from the west side of the Uplift is distinct with a main peak at 880 Ma and lacking grains younger than 650 Ma. Combined geochronological and paleocurrent data suggest that detritus within the syn-orogenic basins was derived from the northern segment of East Gondwana but with additional input of detritus from the Jiangnan Uplift by the late Early Silurian. This information together with analysis of time equivalent strata along strike to the northeast suggests that the Jiangnan Uplift was not a continuous barrier to sediment transport from the southeast but represented part of a discontinuous series of islands supplying local detritus that was mixed with sediment transported from northern Gondwana. [ABSTRACT FROM AUTHOR]

Northeast trending Yong'an Basin, southeast South China Craton, preserves a Permian-Jurassic, marine to continental, siliciclastic-dominated, retroarc foreland basin succession. Modal and detrital zircon data, along with published paleocurrent data, sedimentary facies, and euhedral to subhedral detrital zircon shapes, indicate derivation from multicomponent, nearby sources with input from both the interior of the craton to the northwest and from an inferred arc accretionary complex to the southeast. The detrital zircon U-Pb age spectra range in age from Archean to early Mesozoic, with major age groups at 2000-1700 Ma, 1200-900 Ma, 400-340 Ma, and 300-240 Ma. In addition, Early Jurassic strata include zircon detritus with ages of 200-170 Ma. Regional geological relations suggest that Precambrian and Early Paleozoic detritus was derived from the inland Wuyi Mountain region and Yunkai Massif of the South China Craton. Sources for Middle Paleozoic to early Mesozoic detrital zircons include input from beyond the currently exposed China mainland. Paleogeographic reconstruction in East Asia suggests derivation from an active convergent plate margin along the southeastern rim of the craton that incorporated part of Southwest Japan and is related to the subduction of the Paleo-Pacific Ocean. Integration of the geologic and provenance records of the Yong'an Basin with the time equivalent Yongjiang and Shiwandashan basins that lie to the southwest and south, respectively, provides an integrated record of the subduction of the Paleo-Pacific Ocean along the southeast margin of the South China Craton and termination of subduction of the Paleo-Tethys beneath its southwest margin in Permo-Triassic. [ABSTRACT FROM AUTHOR]

Highlights: [•] The provenance of the Jiyuan basin was established by the detrital zircon U-Pb data. [•] The unroofing pattern of Qinling orogen was established. [•] Comparison of the uplift-denudation of Qinling-Dabie orogen is discussed. [ABSTRACT FROM AUTHOR]

Weathering of basalt in tropical environments is sensitive to climate change and considered to play a significant role in regulating climate evolution. Though extensively studied on the modern Earth and hypothesized for the geological past, basalt weathering is difficult to directly track in geological archives. We here focus on the basaltic sediments derived from the Emeishan large igneous province (LIP) in South China and determined their organic carbon content and isotope, mineral and geochemical compositions. Based on the newly obtained high-precision zircon U-Pb age of 251.79 ± 0.12/0.13/0.36 Ma, we establish temporal variations of weathering intensity for the Emeishan LIP basaltic landscapes in the tropical latitudes through the Permo-Triassic rapid climate warming periods. Analysis of weathering trends indicates a significant decrease in weathering intensity across the Permo-Triassic transition. This decrease in intensity is anomalous considering its coincidence with the climate warming at the Permo-Triassic transition, which tends to elevate chemical weathering rate of basalts and produce sediments with high chemical weathering intensity. Combining these weathering trends with present-day basalt weathering-temperature relationship and reported paleo-temperatures, total erosion rate is quantitatively estimated to increase from 282 ± 43 t/km2/yr in the latest Permian to > 1618 ± 187 t/km2/yr in the Early Triassic. This massive erosion in the Early Triassic is plausibly related to amplified extreme precipitation associated with intensification of the hydrological cycle in the Early Triassic hothouse climate. This study underlines the weathering responses of tropical landscapes to rapid climate warming. • One lowest Triassic claystone layer from South China is dated by CA-TIMS method. • Permo-Triassic weathering trends are reconstructed for the Emeishan basaltic province. • Permo-Triassic denudation rate is quantitatively estimated for the Emeishan basaltic province. • Early Triassic accelerated denudation is related to the intensified hydrological cycle. [ABSTRACT FROM AUTHOR]

Abstract: Sandstone petrology, geochemistry, and detrital zircon U–Pb ages and trace elements are integrated to investigate the provenance of Middle Triassic strata from the Youjiang Basin, SW China. Variations in abundance of volcanic lithic fragments and ratios of Th/U, Zr/Sc and Th/Sc suggest that sandstones from the southwestern portion of the basin display less sedimentary recycling and have a lower felsic average source composition than time-equivalent strata from the central, eastern and northern portions of the basin. All sandstones exhibit an overall similar detrital zircon U–Pb age distribution pattern with major age groups at 1200–900Ma, 480–420Ma and 300–240Ma together with some Devonian–Carboniferous and Neoproterozoic grains. Combined with the compiled paleocurrents, the detrital zircon ages suggest multiple-sourced components. Pre-Devonian detrital zircons were likely derived from the recycled late Neoproterozoic–early Paleozoic clastic rocks and from magmatic and metamorphic rocks related to the early Paleozoic orogeny in the southeastern segment of the South China Craton. Late Paleozoic–Triassic detrital zircons together with the presence of well preserved volcanic lithic fragments were considered to indicate first-cycled detrital input from a subduction–collisional mountain belt to the southwest of the craton. These provenance data argue for an Indosinian mountain building event following the closure of a Paleo-Tethys branch ocean rather than for a thermotectonic reactivation event as recently proposed for the Indosinian orogeny in the southwestern China. In association with this orogeny the Youjiang Basin evolved into a foreland basin. [Copyright &y& Elsevier]

• An earliest Jurassic provenance change has been recognized in the Zigui Basin in central China. • Late Triassic sediments in the Zigui basin were mainly derived from the South China block. • Early Jurassic sandstones in the Zigui basin denote a volcanic source in the Qingling orogen. • Provenance change was ascribed to the collisional orogensis in the Qinling orogen. The Qinling mountains are situated in central China and mark the collisional assembly between the North and South China blocks. To understand the early Mesozoic evolution of the Qinling orogenic belt, we present new paleocurrent data, sandstone petrology and detrital zircon U-Pb ages for Upper Triassic-Lower Jurassic sedimentary successions in the Zigui Basin in the northern margin of the South China block. The deltaic sandstones in the Upper Triassic Jiuligang Formation have high concentrations of quartz grains and the basal alluvial conglomerates of the Lower Jurassic Tongzhuyuan Formation contain abundant chert gravels with sandy matrixs rich in quartz grains. Both the Upper Triassic sandstones and Lower Jurassic conglomerate have two major detrital zircon U-Pb age groups of 2100–1700 Ma and 950–700 Ma with very few Phanerozoic ages. The overlying fluvial sandstones of the Tongzhuyuan Formation display relative enrichment in volcanic and metamorphic rock fragments. They are characterized by primary zircon U-Pb age groups of 250–200 Ma and 950–700 Ma. Consistent with the northwestward paleocurrents, zircon grains of 2100–1700 Ma and 900–700 Ma were likely derived directly or recycled from the Paleoproterozoic and Neoproterozoic basement of the South China Block, with the latter also possibly sourced from the Qinling orogen. The 250–200 Ma age group is understood to be associated with volcanic rock fragments and, considering the southward paleocurrents, indicates a volcanic source within the Qinling orogen. Along with the increased low-grade metamorphic rock fragments in sandstones, this significant provenance change in the Early Jurassic indicates the initial massive erosion and rapid southward propagation of the south Qinling orogen. [ABSTRACT FROM AUTHOR]

• Three tuffaceous layers from North China are dated by CA-TIMS method. • Permo-Carboniferous weathering trends are reconstructed for the southern North China. • A rapid climate warming is documented at the Permo-Carboniferous transition. • The climate fluctuation is causally linked to the Skagerrak-Centered large igneous province. Tracking climate change and its relationships with chemical weathering and massive volcanic activity in deep-time greatly improves our understanding of the Earth's climate system. The Permo-Carboniferous period is a critical time interval with million year-scale glacial-deglacial cycles and massive basaltic volcanism, such as the Skagerrak-Centered (also named Skagerrak or Jutland) large igneous province. To explore the volcanism-climate interactions in this period, we obtained high precision CA-TIMS U-Pb zircon ages for three tuffaceous layers from a cored upper Pennsylvanian-lower Permian marginal marine succession in southern North China. These ages calibrate the Permo-Carboniferous biostratigraphy between ∼301–296 Ma in North China. From this dated core succession, mudrock samples and their calculated weathering index values were screened to constrain the weathering trends for the source landscapes and demonstrate a rapid increase with a subsequent decrease in source chemical weathering intensity during the period of ∼299 to 296.5 Ma. These trends coincide with the southern Gondwana glacial records, low latitude temperature changes, relative sea-level variations, and shifts in atmospheric p CO 2 that together document an earliest Permian climate warming-cooling perturbation with a temperature maximum at ∼298 Ma. This climate warming in the Permo-Carboniferous icehouse correlates with the emplacement of the Skagerrak-Centered large igneous province, which likely released voluminous CO 2 that led to climate warming during the Permo-Carboniferous transition. The immediately following cooling could possibly result from the rapid post-eruptional weathering of the massive basaltic rocks of this province in tropical latitudes, which would have sequestered atmospheric CO 2 and promoted return to cooler icehouse conditions. This study supports the assertation that massive basaltic volcanism could first cause rapid climate warming and then may have an overall net cooling effect as previously suggested for the Deccan Traps and the Central Atlantic Magmatic Province. [ABSTRACT FROM AUTHOR]

The article focuses on findings of a study on Zircon U-Pb Age of the Babu Ophiolites in Southeast Yunnan, China and Constrains of Plate Subduction Time. It states that mafic and ultramafic rocks have been inferred to be part of the Emeishan large igneous province (LIP) by some researchers, and mentions that Zircon grains from sample TGZl as euhedral or prismatic. It notes that mafic and ultramafic rocks in Malipo do not belong to part of the Emeishan LIP.

Abstract: Unconformity bound Permo-Triassic successions in the Qinfang Basin, South China Craton, reflect tectonic processes associated with tectonothermal activity along the margins of the craton. The provenance record of these successions, based on modal analysis, geochemical composition, detrital zircon U–Pb ages, and paleocurrent data indicate derivation from the adjoining Precambrian Yunkai massif and surrounding Paleozoic sedimentary units. The quartz dominated nature of the siliciclastic units, along with their high Th/Sc and Zr/Sc ratios indicate a recycled orogen source. Detrital zircons from Late Permian to Early Triassic samples display major age groups at 1100–800Ma, 650–500Ma, 480–420Ma, with subordinate age groups at 2800–2400Ma, 1900–1600Ma and 1400–1200Ma. Late Triassic sandstones show a similar detrital zircon age pattern as well as a 300–250Ma age group. Integration of this provenance data with regional geological information suggests that the unconformity at the base of the Permian succession is related to subduction of the Paleo-Tethys ocean to the south of the craton, whereas the major driver for Triassic tectonic activity corresponds with terrane accretion and the termination of Paleo-Tethys Ocean subduction along the southwest margin of the craton. [Copyright &y& Elsevier]

Abstract: Devonian strata in the North Qilian Belt of the Qilian Orogen accumulated in a foreland basin formed through collision between the North China Craton and the Central Qilian Belt. U–Pb age data for 393 detrital zircons from four sandstone samples from the Lower to Middle Devonian Laojunshan Formation and Upper Devonian Shaliushui Formation range in age from 3.6Ga to 0.4Ga and indicate input from a multi-component source. Detrital zircons older than the early Mesoproterozoic (1.4Ga) were likely derived from the North China Craton, whereas late Mesoproterozoic to Neoproterozoic zircons were derived from the Central Qilian Belt. Early Paleozoic zircons were derived from the North Qilian continental arc and associated ophiolites. The occurrence of Neoproterozoic zircons indicates that their source, the Central Qilian Belt, was likely once part of the Yangtze Block of the South China Craton prior to its separation from the craton in the late Neoproterozoic. [ABSTRACT FROM AUTHOR]