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Magnetic susceptibility is widely applied in geology, but its use in the study of metamorphic rocks has been limited due to the complex nature of metamorphism. In this study, analyzing a partially retrogressed mafic enclave within Archean TTG gneiss from the Jiaobei Terrane, North China craton, we incorporate magnetic susceptibility with conventional metamorphic (petrographic and major element) proxies in order to investigate profiles of metamorphic retrogression. The magnetic susceptibility results show more complete retrogression in the direction parallel to the tectonic fabric and partial retrogression perpendicular to it. This geophysical observation, which is broadly consistent with the petrological observations and P--T estimates, suggests that the availability of fluids and perhaps even non-lithostatic pressure play roles in the preservation of such differential retrogression. This study thus introduces magnetic susceptibility as a novel proxy in this context, revealing its utility in rapidly and quantitatively identifying variable retrogression gradients consistent with, but with more precision than, measured metamorphic pressures. [ABSTRACT FROM AUTHOR]

The start of the Paleoproterozoic supercontinent cycle is typically taken as the initiation of orogenesis at ca. 2.1 Ga leading to the assembly of Earth's first supercontinent, Columbia. However, the dearth of ca. 2.5–2.2 Ga geological records makes it difficult to deduce tectonic factors during the onset of the Paleoproterozoic supercontinent cycle. The petrogenesis of tonalite–trondhjemite–granodiorite (TTG) provides useful proxies for tracing prevailing geodynamic regimes of early continental evolution. However, marked decreases of TTG and other magmatism occurred across the Archean–Paleoproterozoic transition and have previously precluded forming testable hypotheses. Early Paleoproterozoic TTGs have been identified in the North China Craton (NCC) and other cratons, which may represent the last major pulse of TTGs globally. Here we present low δ18O and δ30Si ca. 2.3 Ga TTGs from the NCC, together with thermodynamic modeling and compilation of stable O and Si isotopes for TTGs globally through time. The ca. 2.3 Ga TTGs were derived from the partial melting of Archean basaltic crust and give lighter average zircon δ18O (3.15 ± 0.35‰) and whole‐rock δ30Si values (−0.17 ± 0.08‰) than most Archean TTGs. Considering coeval mafic‐felsic igneous rocks, and lithospheric thinning since ca. 2.5 Ga based on estimated crustal thickness through the Neoarchean–Paleoproterozoic, we posit the onset of an intraplate rifting consistent with the anomalous low‐δ18O magmatism. Continental rifting of Archean cratons/supercratons plausibly hints at the formation of rifts driving subduction initiation as the veritable onset of the Paleoproterozoic supercontinent cycle. Plain Language Summary: The Earth's first supercontinent, Paleoproterozoic–Mesoproterozoic Columbia, likely began to form during ca. 2.1 Ga (billion years ago) orogenesis. However, the limited record of ca. 2.5–2.2 Ga magmatism makes it difficult to establish how exactly the Paleoproterozoic supercontinent cycle commenced. The tonalite–trondhjemite–granodiorite (TTG) series of felsic rocks forms the backbone of Archean cratons and can provide key constraints on the Earth's early tectonic evolution. Some early Paleoproterozoic TTGs occur in North China and other cratons, which may represent the last major TTG event globally, presenting the possibility to fulfill this role. Here we carry out zircon O and bulk‐rock Si isotopic analyses and thermodynamic modeling for these ca. 2.3 Ga TTGs, together with Si‐O‐Hf data compilation of TTGs globally through time. These ca. 2.3 Ga TTGs show lighter zircon O and bulk‐rock Si isotopes than those of Archean TTGs. They might be formed within‐plate, associated with lithospheric thinning and mantle‐crust remelting to form mafic‐felsic magmatism. We propose an intraplate rift setting for this early ca. 2.3 Ga magmatism, which drove the mobilism that led to the subsequent 2.1–1.8 Ga orogenesis and should be posited as the real start of the Paleoproterozoic supercontinent cycle. Key Points: Ca. 2.3 Ga tonalite–trondhjemite–granodiorite (TTG) in the North China Craton (NCC) shows the affinity of low‐pressure (LP) TTGs and contains low zircon δ18O and bulk‐rock δ30Si valuesCa. 2.3 Ga low δ18O and δ30Si TTG and coeval low‐δ18O magmatism herald the initiation of an intraplate rift settingSuch intraplate rifting hints at the formation of rifts driving subduction as the real onset of the Paleoproterozoic supercontinent cycle [ABSTRACT FROM AUTHOR]

Subduction‐induced metasomatism may increase heterogeneity in the subcontinental lithospheric mantle (SCLM) over time. Syenite and its relevant varieties are typically derived from the most metasomatized portions of the SCLM and thus provide a key to decipher its heterogeneity. The only circum‐cratonic syenite province in the world, the Late Triassic belt around North China craton, is unique and offers an opportunity to investigate heterogeneity of the SCLM right before its destruction in the Mesozoic. New and previous data of whole‐rock Sr‐Nd and zircon in situ Hf‐O isotopes of syenite intrusions encircling the craton indicate two distinct types of metasomatism characterized by an alteration of juvenile or ancient materials. The spatiotemporally distinct sources can be discriminated by melts from oceanic slabs subducting beneath much of North China followed by deep subduction of South China craton only in the south. This unique setting of a circum‐cratonic syenite belt proves in a single case study that subduction‐induced metasomatism may cause craton‐scale SCLM heterogeneity. Plain Language Summary: The subcontinental lithospheric mantle (SCLM), comprising the roots of cratons, is depleted, rigid, and buoyant, all of which contribute to maintaining the stability of a craton. However, the SCLM can be replenished and destroyed by melts from recycled subducting slabs, known as mantle metasomatism. SCLM heterogeneity can be caused by metasomatism by carbonate and silicate melts derived from subducted oceanic and continental plates. It can then be recorded by mantle xenoliths or mantle‐derived rocks, but such records are typically either highly localized or asynchronous with other such records. In this study, Triassic syenites of North China craton that are distributed craton‐wide and coeval provide a chance to investigate SCLM heterogeneity through whole‐rock Sr‐Nd isotopes and zircon in situ Hf‐O isotopes. We propose that the contrasting subduction systems related to the Paleo‐Asian and Paleo‐Qinling oceanic plates subducting on the northern and southern margins of North China craton, respectively, as well as the deep continental subduction of South China craton to the southeast of North China, gave rise to the observed SCLM heterogeneity during the Permo–Triassic, which provided a preconditioning for the later Mesozoic lithospheric destruction of the cratonic root. Key Points: A unique circum‐cratonic Triassic syenite belt from North China craton (NCC) reveals heterogeneity of the subcontinental lithospheric mantleDifferential subduction systems surrounding NCC during the Permo–Triassic caused the heterogeneity through mantle metasomatismEarly Mesozoic mantle metasomatism served as a preconditioning for lithospheric destruction of NCC before the effect of the Pacific Ocean [ABSTRACT FROM AUTHOR]

Granulites represent high-grade metamorphic rocks of the deep continental crust. The metamorphism and exhumation of granulites from Archean terranes provide insights into the crustal evolution of Archean cratons and shed light on the formation and reactivation of cratons. We present petrology, U–Pb geochronology (zircon, rutile, and titanite), and pressure–temperature (P–T) paths for metadiabase dikes in an Archean granulite terrane of the North China Craton. Garnet (Grt) coronae in the metadiabase dikes are developed between plagioclase (Pl) and clinopyroxene (Cpx) via the reaction Pligneous + Cpx → Pl1 + Grt ± quartz. The reaction proceeds inward within the plagioclase, progressively consuming Pligneous (XAn = 0.65–0.69) and leaving Ca-poor Pl1 (XAn = 0.46–0.53) as the residue. Geothermobarometry and P–T pseudosections suggest peak conditions for garnet formation at ~800°C and 10–13 kbar. During retrograde metamorphism, Grt broke down to Ca-rich Pl2 (XAn = 0.73–0.74), and ilmenite replaced rutile. Geothermobarometry and Zr-in-titanite temperatures constrain the P–T conditions of retrograde metamorphism at 700–750°C and 4.5–7.5 kbar. Zircon and titanite U–Pb geochronology shows that the protolith of the metadiabase dike was formed at 2.4 Ga and underwent granulite-facies metamorphism at 1.86 Ga. The intrusion of mafic dikes into the Archean granulite terrane indicates that the Archean basement was also heated and buried in the Paleoproterozoic. The metadiabase dikes and the hosting Archean basement underwent Paleoproterozoic granulite-facies metamorphism at a depth of ~40 km, followed by near-isothermal decompression and subsequent near-isobaric cooling (cooling rate of 1–3°C Myr−1) at depths of 15–25 km. Crustal shortening and thickening may have been caused by the underplating of the Khondalite series beneath the Archean basement during the amalgamation of supercontinent Columbia. The Paleoproterozoic orogeny induced a second generation of metamorphism of the Archean basement along the margin of the craton and drove the exhumation of the Archean granulite terranes to the middle crust (~15 km). [ABSTRACT FROM AUTHOR]

The Ordovician–Silurian transition experienced severe, but enigmatic, glaciation, as well as a paradoxical combination of mass extinction and species origination. Here we report a large and fast true polar wander (TPW) event that occurred 450–440 million years ago based on palaeomagnetic data from South China and compiled reliable palaeopoles from all major continents. Collectively, a ~50˚ wholesale rotation with maximum continental speeds of ~55 cm yr−1 is demonstrated. Multiple isolated continents moving rapidly, synchronously, and unidirectionally is less consistent with and plausible for relative plate motions than TPW. Palaeogeographic reconstructions constrained by TPW controlling for palaeolongitude explain the timing and migration of glacial centers across Gondwana, as well as the protracted end-Ordovician mass extinction. The global quadrature pattern of latitude change during TPW further explains why the extinction was accompanied by elevated levels of origination as some continents migrated into or remained in the amenable tropics. Palaeomagnetic data from South China and compiled reliable palaeopoles from 4 other continents reveals a ~50˚ true polar wander (TPW) event occurring 450–440 million years ago. Sweeping Gondwana across the South Pole, this TPW event induced the Ordovician glaciation and mass extinction. [ABSTRACT FROM AUTHOR]

Large‐scale strike‐slip faulting commonly occurs in active tectonic margins, but rarely, if ever, do large faults cut deep into ancient continental nuclei known as cratons. With thick mantle roots, cratons are considered to be the most tectonically stable portions of Earth's continental lithosphere, with an eminent exception being the relatively recent destruction of North China craton. Here, we show that from 240 to 165 Ma ago the roughly coeval continental collisions of South China to the south and Mongolia to the north ruptured the Tanlu fault within the then thick North China craton. A large ~450 km displacement mechanically induced by a ~16° intracratonic rotation along the Tanlu fault reconciles the offsets of geological piercing points and palaeomagnetic data of North China on either side of the fault. Shortly after the displacement of the only large young strike‐slip cratonic fault, the cratonic lithosphere of eastern North China collapsed. [ABSTRACT FROM AUTHOR]

The Cryogenian Period (717–635 Ma) experienced two low‐latitude "snowball Earth" glaciations, the Sturtian and the Marinoan of contrasting 57 and <16 Myr durations, respectively. A lack of reliable age controls on extensional tectonics and associated magmatic rocks during the Marinoan has hampered an understanding of the deglaciation. Furthermore, although deglaciation is generally assumed to have occurred once ongoing magmatism accumulated enough atmospheric CO2, as suggested by cap carbonates, specific geologic evidence linking volcanic events with deglaciation are lacking. Here, we present high‐precision zircon geochronology with chemical abrasion‐isotope‐dilution isotope ratio mass spectrometry that indicates an extensive and thick sequence of rift‐related magmatic rocks in South Qinling, Central China, erupted 2–6 Myr before the termination of the Marinoan. Climate modeling proposes a scenario explaining why the Marinoan was the shorter snowball and how volcanism may have driven the deglaciation. Plain Language Summary: Volcanic CO2 and dust emissions have been regarded as the major driver for Marinoan deglaciation. Most of CO2 outgassing is associated with seafloor spreading and subduction (arc magmatism), which are ongoing processes on geological timescales. To drastically increase CO2 emissions, there must have been many active rift zones during Marinoan glaciation. We provide age constraints on a previously little‐known major Marinoan rift‐related volcanic suite in South Qinling, which reveals volcanic activity lasting 4 Myr and ending 2 Myr before the termination of the Marinoan snowball Earth. Climate modeling provides constraints for the ice‐age duration deduced from the geological setting. Key Points: Volcanism is dated at 641–637 Ma using chemical abrasion‐isotope‐dilution isotope ratio mass spectrometry techniqueClimate modeling on the volcanism‐related CO2 emission is conductedEnhanced volcanic‐related dust and CO2 emission can shorten the Marinoan snowball Earth by 2–5 Myr [ABSTRACT FROM AUTHOR]

Paleo‐Pacific subduction generated a prolonged active continental margin along the coast of the South China Block (SCB). A Triassic magmatic gap was argued to have occurred and was ascribed to flat‐slab subduction of an oceanic plateau. We study for the first time a >330‐m‐long core of typical arc volcanics dated at ca. 218 Ma from the Meiji Atoll in the southern South China Sea (SCS). Paleomagnetism suggests 4.1°± 1.5° of post‐eruption southward drift. These observations clearly support the existence of a Triassic arc in the SCB and imply that part of the arc later split off and drifted southward during the opening of the SCS in the Oligocene. Our results better constrain the lateral extent of the proposed flat‐slab subduction along the margin of the SCB. Moreover, we provide direct evidence of how the breakaway of ribbon continents operated in active continental margins, a recurrent scenario that has been invoked for Phanerozoic tectonics and continental growth throughout Asia. [ABSTRACT FROM AUTHOR]

The striking coincidence of the Franklin large igneous province (LIP) and the Sturtian glaciation onset ca. 717 million years ago (Ma) has inspired the hypothesis that either basaltic weathering or stratospheric sulfate aerosol injection of the Franklin LIP plunged Earth into global glaciation. The cool background climate just before the Sturtian has been commonly invoked by such initiation models. Difficulty in definitively linking these concepts with geological evidence has precluded complete demonstration of a snowball trigger mechanism. Here, we report that Franklin-aged magmatism was not only present in Laurentia and Siberia, but also in South China, where the Hubei–Shaanxi Magmatic Province formed at 720 Ma, revealing widespread magmatic provinces immediately preceding the onset of the Sturtian snowball Earth. Geochronological and geochemical data suggest that the geographically widespread magmatic provinces were emplaced over a short duration (ca. 720–717 Ma) and likely related to a mantle superplume beneath supercontinent Rodinia. We propose that low-to-mid-latitude volcanism prior to the Sturtian by a few million years enhanced global weatherability and created the background cool climate for the superimposed shock of stratospheric sulfate aerosol injection of the terminal Franklin eruption. Such widespread 720–717 Ma volcanism on different continents may have driven the Sturtian snowball initiation. • A Franklin-aged magmatic province (720 Ma) has been identified in South China. • Widespread volcanism across Rodinia initiated at ca. 720 Ma and lasted until the ca. 717 Ma Sturtian onset. • This ca. 720–717 Ma volcanism extended across Rodinia from tropical to temperate latitudes. • Widely distributed, coeval volcanism is interpreted to be related to a mantle superplume beneath supercontinent Rodinia. • Such rapid and widespread volcanism may trigger the Sturtian glaciation onset. [ABSTRACT FROM AUTHOR]

The Mesozoic terrestrial Jehol Biota of northern China exceeds the biomass and biodiversity of contemporaneous Lagerstätten. From 135 to 120 Ma, biotic radiation may have responded to the peak destruction of the North China Craton. However, the direct mechanistic link between geological and biological evolution is unclear. Phosphorus (P), a bio-essential nutrient, can be supplied by weathering of volcanics in terrestrial ecosystems. The middle–late Mesozoic volcanic-sedimentary sequences of northern China are amazingly rich in terrestrial organisms. Here we demonstrate episodic increases in P delivery, biological productivity, and species abundance in these strata to reveal the coevolution of volcanism and terrestrial biotas. A massive P supply from the weathering of voluminous volcanic products of craton destruction thus supported a terrestrial environment conducive to the high prosperity of the Jehol Biota. During the nascent stage of craton destruction, such volcanic-biotic coupling can also account for the preceding Yanliao Biota with relatively fewer fossils. [ABSTRACT FROM AUTHOR]

Subduction erosion at convergent margins is a leading mechanism for the destruction (recycling and reworking) of continental crust. But because of the lack of direct evidence, it is not straightforward to identify erosive events and their intensities in fossil subduction zones. The Heilongjiang accretionary complex in northeastern China was formed during the early Mesozoic subduction of the Paleo-Pacific Ocean. We investigated amphibolites from this accretionary complex, whose protoliths (based on whole-rock trace elements and Sr-Nd-Hf isotopes) were mafic continental arc magmatic rocks (255-249 Ma; zircon core U-Pb ages) from the upper plate. Phase equilibria modeling constrained by mineral geochemistry indicates that the amphibolites and their wall rocks were first heated to low granulite facies (750-800 °C, ~7 kbar) at 251-244 Ma (zircon rim U-Pb ages) and then cooled to ~700 °C with increasing pressure (8-9 kbar) before 213-187 Ma (titanite and apatite U-Pb ages). To explain the occurrence of the lower arc crustal lithologies in the accretionary complex and their metamorphic history, we propose that the subducting plate strongly eroded the forearc crust, allowing the plate interface to advance landward and scrape the amphibolites and wall rocks formed under the old arc, which finally were exhumed along the subduction channel and became components of the complex. The case study exemplifies direct petrological evidence of strong subduction erosion occurring in an ancient orogen, thus implying that consumption of the entire forearc crust could occur within only ~50 m.y. [ABSTRACT FROM AUTHOR]

The mechanism and timing of crustal growth and differentiation on early Earth are debated. Evidence of crustal differentiation is detectable as deviations from Earth's assumed chondritic uniform reservoir (CHUR) as crust is extracted from the mantle leading to a melt-depleted reservoir. For the long-lived zircon Lu-Hf system, no incontrovertible evidence of significant mantle depletion >3.8 Ga exists. We conduct combined U-Pb and Lu-Hf isotopic analyses for the detrital zircon from the Caozhuang supracrustal sequence in North China. The zircon Hf isotopic compositions are broadly scattered along the CHUR evolution line. However, given the possibility of potential systematic biases in zircon petrogenesis and the unique tectonic setting of early Earth, we posit that magmatism controlled by the nascent forms of plate tectonics during the Eoarchean could have likely hidden the degree of ancient crust-mantle differentiation. The non-depleted zircon Hf isotopes observed in North China and globally during early Earth may in verity imply the existence of ubiquitous depleted mantle domains at that time. [ABSTRACT FROM AUTHOR]

Lead isotopes of Earth's accessible silicate rocks are generally too radiogenic for the planet to have formed from meteoritic material—a problem known as the first Pb paradox. The search for an unradiogenic reservoir to balance Earth's bulk composition has thus focused, with varying degrees of success, on inaccessible rocks in the core, mantle, and lower crust. Whether the lower continental crust balances the radiogenic depleted mantle and upper crust is debated and largely depends on how unradiogenic the lower crust, in particular the Archean lower crust, is. In this work, granulite terrain, granulite xenoliths, and lower crustal-derived granitoids from the same region of the northern North China craton (NCC) are combined to constrain the Pb isotopic compositions of the late Archean lower crust. The Hannuoba pyroxene-rich mafic granulite xenoliths are interpreted as restites left after partial melting of the late Archean lower crust to produce the Mesozoic granitoids. Both the xenoliths and granitoids have similar Pb isotopic compositions that are much more radiogenic than the granulite facies gneisses from the Huai'an terrain. The results rule out the notion that the lower crust is inherently poor in U and Th relative to Pb and suggest that the Pb isotopic compositions of the granulite facies gneisses are not representative of the Archean lower crust. This rule may be generally applicable to other regions because the Huai'an terrain is chemically and isotopically comparable with several other Archean unradiogenic granulite terrains (e.g., the Lewisian). We argue that the late Archean lower crust may not be so extremely unradiogenic in Pb isotopic compositions as commonly thought and the lower crust appears insufficiently unradiogenic to balance the accessible Earth. We also provide evidence that intracrustal differentiation via lower crustal melting could be an important mechanism causing the elevated Th/U and 208Pb/206Pb in the upper crust. [ABSTRACT FROM AUTHOR]

Tonalite–trondhjemite–granodiorite (TTG) rocks consitute the dominant felsic lithology of the Archean crust in most cratons, but their petrogenesis and geodynamic setting are still matters of great debate. Here, we report new Fe isotopic analyses for ca. 2.5 Ga diorites and TTGs with compositions typically interpreted to reflect a high-pressure affinity in eastern Hebei Province of the North China craton. Whole-rock Fe3+/∑Fe and δ 56 Fe of the trondhjemites show strong correlations with MgO and Fe 2 O 3 T, both indices of igneous differentiation, supporting the radical reinterpretation that the apparent "high pressure" signatures in the trondhjemites instead formed by amphibole-dominated fractionation at low pressure. Likewise, for the tonalites, their light Fe isotopes make them unlikely to be the melting products of enriched mafic rocks at high pressure within the garnet stability range. Thus, Fe isotopes support that "high pressure" TTGs in verity formed at lower pressure with little involvement of residual garnets. Our results thus challenge the evidence once purported to infer Archean subduction. • Fe isotopes can see through the complex process and the disturbance of accessory minerals during TTG production. • Fe isotopes support HP TTGs formed by fractional crystallization at low pressure. • No obvious difference when comparing the Fe isotope of Archean TTGs with differentiated Phanerozoic rocks. [ABSTRACT FROM AUTHOR]

• A 1800–1600 Ma hotspot track is proposed by correlating major large igneous provinces globally. • This track is consistent with that deduced from paleomagnetic apparent polar wander. • A subduction-controlled plume origin explains mantle convection at the dawn of supercontinents. • The track establishes the oldest link between bottom-up and top-down tectonic processes. The concurrence of both global orogenesis and large igneous provinces (LIPs) from 2200–1600 Ma remains enigmatic. This apparent contradiction of top-down and bottom-up geodynamics occurred during assembly of Earth's oldest-known supercontinent. We present a multidisciplinary study combining the dismembered portions of major LIP worldwide and correlate them across supercontinent Columbia to the same plume center (Xiong'er of the North China craton). The succession of LIPs is then used to trace the oldest established hotspot track associated with a pulsating plume constraining ancient plate motion. Subduction-controlled plume generation can explain mantle upwelling occurring where subducted slabs forming the supercontinent had previously sunk to the base of the mantle and advected the Xiong'er mantle plume due to return flow. Tectonic motion detected by the hotspot track can account for both those regions of the supercontinent with and without LIPs. Such historical constraints on the interaction between plumes and subduction are critical in linking bottom-up and top-down tectonic processes at the dawn of the supercontinent cycle. [ABSTRACT FROM AUTHOR]

The Statherian Period (1.8–1.6 Ga), currently the final period of the Paleoproterozoic Era, is named "stable, firm" for the interval following orogenesis (the Orosirian Period) that culminated in the assembly of likely Earth's first supercontinent, Columbia. Thus, the Paleoproterozoic–Mesoproterozoic boundary is supposed to demarcate increased continental "stability", defined as a transition from orogenesis and arc magmatism to unmetamorphosed shallow-water cover sequences and intraplate magmatism. It has become apparent, however, that (i) the assembly of Columbia appears to be highly diachronous and (ii) many stable cover sequences once mapped as Mesoproterozoic appear to pre-date 1.6 Ga quite significantly. These discrepancies have led to the recent suggestion by a large group of Precambrian geologists that the Statherian Period belongs more to the Mesoproterozoic Era and thus that the end of the Paleoproterozoic Era should be redefined at ca. 1.8 Ga. North China Craton is one such craton that has pre-1.6 Ga stable sedimentary covers, but dating the base of the basins have proven difficult and thus other indicators of continental stability must be sought. Here we present new geochronological and geochemical data from two dyke swarms at 1.70 and 1.62 Ga from western Shandong Province (Luxi area) of the North China Craton that can be used to constrain the tectonic setting at this critical interval in question. Precise U-Pb SIMS analysis yields baddeleyite 207Pb/206Pb ages of 1700 ± 5 Ma (n = 9, MSWD = 0.14) and 1620 ± 4 Ma (n = 14, MSWD = 0.56). The new dated ca. 1.62 Ga Xiaobeizhuang dyke (330° trending, >15 m wide) belongs to the coeval Taishan dyke swarm. The ca. 1.70 Ga swarm, newly discovered in the North China Craton, is referred to as Ximaiyao dyke swarm (340 – 345° trending, 0.4 – 13 m wide). Paleogeographic affinities of the North China Craton with the São Francisco Craton in supercontinent Columbia are considered in light of this newly identified swarm. Given that both dyke swarms pre-date 1.6 Ga and that their geochemistry implies intraplate magmatism, our new data support the suggestion that this time is more Mesoproterozoic than Paleoproterozoic in character. These pre-1.6 Ga intraplate dyke swarms, including the 1.78 Ga, the 1.73 Ga, and later 1.70 Ga and 1.68–1.62 Ga swarms, thus provide local support from North China Craton for redefining the base of the Mesoproterozoic Era as ca. 1.8 Ga and including the Statherian Period, consistent with the ages of platform cover sequences. • North China craton developed ca. 1.70 Ga and 1.62 Ga intraplate dyke swarms. • The 1.70 Ga dykes could match the coeval swarm in the São Francisco craton. • Intraplate magmatism from 1.78–1.62 Ga heralds the onset of the Mesoproterozoic. [ABSTRACT FROM AUTHOR]

The North China Craton (NCC) provides a world-class example for how the destruction of a cratonic root can significantly influence metal and energy resources. The Bohai Bay Basin and Ordos Basin are two super basins that developed in the eastern and western NCC, respectively. Both basins witnessed the decratonization of NCC. However, their dominant energy-producing layers are vastly different, with vast Paleozoic natural gas resources in the Ordos Basin but mostly Cenozoic oil resources in the Bohai Bay Basin. The distinct hydrocarbon evolution periods of the two basins since the late Paleozoic coincides with different stages of the NCC destruction. However, the direct association between the NCC destruction and hydrocarbon evolution has not been has not been explicitly revealed or studied in detail. In this comprehensive review, a four-stage hydrocarbons accumulation model related to NCC destruction is presented: 1) Homogeneous late Paleozoic (ca. 299–252 Ma) source and reservoir rocks formation across the entire craton due to the activation of cratonic margins; 2) divergent evolution from the early Mesozoic (ca. 252–165 Ma) caused by the initiation of westward flat subduction of the Paleo-Pacific slab, where the west NCC formed thick sedimentary strata (marked by the Yanchang Formation in the late Triassic) while east NCC experienced a depositional hiatus; 3) NCC destruction peak in the mid-late Mesozoic (ca. 165–66 Ma) that contributed to the voluminous natural gas generation in the west, resulting from the thermal perturbation of delamination or slab rollback; 4) continuous Cenozoic extension and elevated geothermal field (ca. <66 Ma) related to mantle upwelling (ca. 35–20 Ma) caused by the present-day Pacific slab subduction, resulting in thick lacustrine deposition of Cenozoic and maturation of Upper Paleozoic source rocks. We thus conclude that both differences and similarities between the two super basins of North China can be explained by the shared Paleozoic depositional conditions and the inhomogeneous Mesozoic destruction state across the craton. This entire process was initiated by the westward subduction of the paleo-Pacific plate that resulted in the change of tectonic regime of eastern China. The intense decratonization in the eastern NCC resulted in the partial destruction of the Paleozoic reservoirs, while continuous Cenozoic extension facilitated the formation of significant oil resources in the Bohai Bay Basin. This study highlights the importance of investigating the more homogeneous Paleozoic strata for undiscovered hydrocarbon resources. • Inhomogeneous North China Craton destruction on super basins formation is revealed. • Contrasting hydrocarbon enrichment models related to craton evolution is proposed. • Stable lithospheric structure benefits Paleozoic oil and gas in western craton. • Lithospheric thinning contributes to Cenozoic oil and gas in eastern craton. [ABSTRACT FROM AUTHOR]

In the paleogeographic configuration of the Neoproterozoic supercontinent of Rodinia, the Tarim craton (northwestern China), traditionally seen as a single block, is placed either on the periphery near northern Australia or India or in a central position between Australia and Laurentia. To distinguish between these possibilities, we present here new primary paleomagnetic results from ca. 900 Ma volcanics in the Aksu region of the northwestern Tarim craton. The data reveal a ~28° latitudinal difference between the North Tarim and South Tarim blocks at ca. 900 Ma and constrain the age of amalgamation of the Tarim craton to between 870 and 820 Ma. Combining paleomagnetic poles from Tarim and major cratons of Rodinia with geological evidence, a two-stage orogenic model is proposed for the assembly of Rodinia. Late Mesoproterozoic orogenesis (1.3-1.0 Ga) led to the assembly of Australia-East Antarctica, Baltica, Umkondia, South Tarim, and Cathaysia with Laurentia, forming the core of Rodinia. Thereafter, the Jiangnan-Central Tarim Ocean separating North Tarim and Yangtze from South Tarim and Cathaysia was closed before ca. 820 Ma. This second Jiangnan-Central Tarim orogeny caused nearly coeval amalgamation of the peripheral Tarim and South China cratons by the welding of North Tarim and Yangtze to South Tarim and Cathaysia, respectively. The supercontinent of Rodinia was thus assembled by two orogenic phases separated by ~200 m.y. [ABSTRACT FROM AUTHOR]

[Display omitted] [ABSTRACT FROM AUTHOR]