The extensive Paleoproterozoic iron formations (IFs) distributed across the North China Craton serve as ideal proxies for understanding the redox variations in paleo-oceans before and after the Great Oxidation Event (GOE). Here, we present a comprehensive analysis of the lithofacies, mineralogy, and geochemical characteristics of the granular iron formation (GIF) within the Paleoproterozic Wuzhiling Formation of the Songshan Group in the southern North China Craton. Our findings reveal that the GIF represents a chemical sedimentary rock, precipitated within a water column characterized by layered oxygen-depleted to suboxic conditions. The protolith sediments of the GIF in the Wuzhiling Formation are hypothesized to have comprised quartz-coated hematite microparticles, along with precursor deposits of aragonite and hexagonal iron oxides, commonly referred to as green rust. Mineralogically, the GIF is predominantly composed of quartz and hematite, with the iron content attributed to the weathering processes of continental crustal materials, the influence of low-temperature hydrothermal fluids, and the incorporation of iron from seawater. During the GOE, a pivotal transition in Earth's history, the (Pr/Yb) ratios normalized to PAAS (Post-Archean Australian Shale) standards exhibit increased dispersion, accompanied by a gradual decrease in the Y/Ho ratios. These geochemical shifts suggest a pronounced alteration in the ancient marine environment, transitioning from a monolithic reducing state to a more complex redox stratification within the seawater after the GOE. In summary, this study contributes to the reconstruction of paleo-ocean redox conditions around the GOE, providing evidence for the re-establishment of Precambrian paleoenvironmental conditions.

Abstract U–Pb dating of detrital zircon is widely used in geology to identify the source of sediments and constrain palaeogeography and tectonic history. We collected the detrital zircon from the Paleoproterozoic to early Palaeozoic strata to understand the North China Craton's geological chronological characteristics. After screening and sorting out data information, we managed and analysed 84 papers from 2006 to 2022. Three hundred seventy‐nine samples comprising 29,431 pieces of U–Pb ages of detrital zircons gathered from the Proterozoic to Ordovician sedimentary rocks in North China Craton (NCC). Detrital zircons within five areas in the NCC, i. e., Xuhuai Basin, Zhaertai‐Bayan Obo‐Huade Basin, Yanliao Basin, Xiong'er Basin and Alxa Block, are discussed in detail. Meanwhile, we collected 2,588 pieces of Lu‐Hf detrital zircon data in the study. This Database can be helpful in understanding and explaining the tectonic evolution of the NCC from the Paleoproterozoic to the Early Palaeozoic.

The Xiong'er volcanic-sedimentary succession in the southern North China Craton (NCC) documents crucial data regarding the geological evolution of the supercontinent Columbia (Nuna). Previous researches largely focused on the volcanic rocks in the Xiong'er succession, while the paleo-tectonic significance of its sedimentary rocks has not been explored. LA-ICP-MS detrital zircon U-Pb dating and whole-rock geochemistry of the interlayered sedimentary units within the succession are conducted to ascertain the provenance and tectonic driver of the basin infill. New chronological constraint suggests the deposition of the succession persisted until ca. 1710 Ma, temporally aligned with the initial deposition of the overlying Ruyang Group. Normalized rare earth elements (REE) and classification diagrams indicate derivation predominantly from felsic sources with supplementary input from mafic sources. Detrital zircon U-Pb ages indicate a major 2.5 Ga provenance from the proximal latest Archean and Paleoproterozoic metamorphic complexes and a subordinate ca. 2.3 similar to 1.8 Ga provenance from adjacent regions. Notably, an elevated ca. 1.8 similar to 1.7 Ga detrital zircon peak in the uppermost section of the succession implies contributions from coeval granites and volcanogenic rocks. Integrating these observations with the stratigraphic progression, the Xiong'er succession is interpreted as a magma-rich syn-rift basin infill and we hypothesize the existence of a "breakup unconformity" separating the syn-rift Xiong'er Group from the overlying post-rift Ruyang Group.

Large igneous provinces (LIPs) are mostly eroded in deep time; nevertheless, their plumbing systems remained in the crust and weathered materials may be traced in basins. Vestiges of the early Neoproterozoic LIPs are investigated in the North China craton. Two large doleritic sills are dated at ca. 940 Ma and ca. 890 Ma in the Pyongnam basin in Korean peninsula, which are comparable with those coeval ones in the other two basins of the Xuhuai rift. Both of them are featured by ocean island basalt-akin trace element patterns. The ca. 890 Ma sills show stronger depletion in mobile elements, and slightly higher differentiated light and heavy rare earth elements than the ca. 940 Ma sills. They are also chemically affinitive with the ca. 920 Ma Dashigou LIP, but with slightly higher MgO and total alkalis and more differentiated light and heavy rare earth elements. This may indicate a similar (plume) source with probably lower degrees of partial melting in the source region(s) in the magma chamber than the 920 Ma one. Together with the Dashigou, they comprise a cluster of LIPs from the same plume with sequential peaks at ca. 940 Ma, 920 Ma and 890 Ma. Ages of sills and the youngest detrital zircons constrain the sediments to be within 1160-940 Ma for the 940 Ma sill-hosting lower-middle section (e.g., Jikhyon-Mukchon groups) and 940-890 Ma for the 940 Ma-sill free upper section (e.g., Myoraksan Group). A synthetic dataset of all the three basins of the Xuhuai rift reveals a similar depositional age and a similar major provenance (940-900 Ma) for the black-greenish shale-featured formations (e.g., Socheong-XingmincunJinshanzhai formations), which are right above the carbonates with negative inorganic carbon (Majiatun) excursion across much of the Xuhuai rift. The significant 940-900 Ma provenance is featured by zircons resemble those from the local LIPs. It is possible that the provenance was the relevant extrusive rocks of the 940-890 Ma LIPs. This further implies that the ca. 940-920 Ma Majiatun excursion is concurrent with the LIP cluster and is possibly a result of instant turbulence of carbon cycle by the LIPs.

The Meso- to Neoproterozoic Eras were characterized by environmental, evolutionary, and lithospheric stability in the North China Craton (NCC). It is controversial that huge uplift(s) occurred in the North China Craton during this period. The southern NCC developed early terrestrial deposition in the late-Paleoproterozoic and glacial sequence in the late Neoproterozoic record integrated geological history of the NCC in the intervening interval. Geochemistry compositions of mid-Mesoproterozoic carbonaceous slates (ca. 1330 Ma) show similar provenances to the underlying Mesoproterozoic sedimentary rocks in the southern NCC. Detrital zircons from the mid-Mesoproterozoic strata yield U-Pb ages from ca. 2450 to 1850 Ma with minor ages of 2950 and 2750 Ma. U-Pb ages of detrital zircons from the Neoproterozoic strata yield from ca. 1700 to 1000 Ma besides peak ages of 2600, 2400, and 1950 Ma. The early Paleozoic sedimentary rocks also display peak ages between ca. 1850 and 1000 Ma along with peaks at ca. 2500 and 2300 Ma. These detrital zircon ages are quite different from those of the Mesoproterozoic sedimentary rocks in the NCC. According to paleogeography study, the late-Paleoproterozoic to the early Mesoproterozoic clastic sequences are controlled by Xiong'er volcanic event in the southern NCC and carbonate platform developed later. The Mesoproterozoic sequences are overlain disconformably by the Neoproterozoic strata. In combination with compiled magmatic and detrital zircon ages, a sedimentary gap spanned at least 300 Ma from mid-Mesoproterozoic to Neoproterozoic in the southern NCC. Thus, the disconformity between the Mesoproterozoic and Neoproterozoic sedimentary sequences in the southern NCC should represent a huge sedimentary hiatus. Both the variable provenances and huge sedimentary hiatus between the Mesoproterozoic and Neoproterozoic sedimentary sequences support that the NCC might not split from relict landmass of Columbia Supercontinent before Neoproterozoic. The relict landmass was involved in aggregation of the Rodinia supercontinent. [GRAPHICS] .

The early Neoproterozoic sediments in the southern–southeastern (S-SE) North China Craton (NCC) are critical in paleogeographic reconstruction. We present new detrital zircon U–Pb–Hf data of five sandstone samples from the Sangwon Supergroup in SE-NCC and the Wufoshan Group in S-NCC. We integrate published zircon U–Pb data to appraise their provenance. The new dataset constrains the maximum depositional age of the Sangwon Supergroup to be ca. 1.0 Ga. The similar provenance transition and the comparable sequence stratigraphy imply that the Wufoshan Group could be an extension of the Xuhuai–Dalian–Pyongnam basins in the SE NCC with a maximum depositional age of ca. 1.0 Ga. The zircon age spectra of the successions show four major populations at ca. 2.5 Ga, ca. 2.0–1.8 Ga, ca. 1.6–1.4 Ga, ca. 1.3–1.0 Ga, with rare >2.5 Ga grains. The Archean–Paleoproterozoic grains could be derived from the NCC, which is confirmed by their εHf(t) values. After a review of the possible paleocontinental reconstructions, we suggest that the ca. 1.6–1.0 Ga grains with different εHf(t) values (mostly positive) were from the southwestern Congo craton, supporting a NCC–SW Congo/SE NCC-S São Francisco connection at ca. 0.9 Ga.

Abstract The North China craton is encircled by four successive triple-conjugated rifts, which are respectively the centres of large igneous provinces (LIPs) of bimodal compositions, i.e. Xiong'er rift (south, c. 1.78 Ga Taihang LIP), Yanliao rift (north, c. 1.32 Ga Yanliao LIP), Xuhuai rift (east, c. 1.23 Ga Licheng and c. 0.92 Ga Dashigou LIPs) and Langshan rift (west, c. 0.82 Ga Qianlishan LIP). These rifts are genetically related to their contemporaneous LIPs based on their consistent geometry. Spatial migration of these rifts and LIPs indicates their propagation from along one marginal side to the opposite side of the craton, which may have resulted in the sequential breakup of the proto-North China craton from one side to the other during 1.8–0.8 Ga. However, the observation that the lithosphere under the LIP-associated rift regions is less destroyed (decratonized) in the Mesozoic indicates a possible role of LIPs in strengthening intracratonic steady state. This study shows that LIPs may change craton stability in either direction.

The late Paleoproterozoic Dagushi Formation comprises a fluvial-lacustrine succession and represents the initial fill of the Xiong'er Basin in the southern North China Craton. Employing integrated outcrop surveys and detrital zircon U-Pb-Hf dating, this study examines the provenance and depositional setting of the Dagushi Formation. Five major depositional facies, including braided channel, distributary channel, subaqueous stream/mouth bar, pro-delta and shallow lake, were identified, based on lithofacies and associations. They were interpreted as representing a braided river delta-lacustrine system. The ages of the last metamorphic event of the basement, covering volcanics and the youngest zircon together constrain a depositional age of ca. 1.79 Ga for the Dagushi Formation. Zircon age distributions reveal a provenance change from ca. 2.7-2.5 Ga rocks in the lower part, to ca. 2.3-1.9 Ga sources in the middle-upper part of the Dagushi Formation. Considering the vertical sedimentology, this provenance change could be induced by the rising water-level caused by a tectonic subsidence. The ca. 2.7-2.5 Ga zircons are suggested to be locally sourced from the late Neoarchean-Paleoproterozoic metamorphic basement. The northeast Zhongtiao Mts area (current co-ordinates) is supposed to have appeared as a paleo-uplift and served as a source area for the Paleoproterozoic grains. The Dagushi Formation records an early 'underfilled' stage of the Xiong'er Rift.

The evolution of oxygen-increasing is one of the most significant events in the history of the Earth. It is controversial if there are variable oxygen levels in Proterozoic. Fine-grained sedimentary rocks, which record the redox state of the ocean sensitively, can be used in constraining the oxygen levels. A series of shales in the North China Craton ( NCC ) were deposited in extension environments after 1800Ma. Variegated shales, from the black shales in a shelf-neritic environment ( ca. 1648Ma) , were carried out in mineralogy and geochemistry study. Scanning electron microscope and X-ray diffraction ( XRD) show purplish-red and dark-green flaky shales mainly consist of illite, quartz and K-feldspar. Hematite distributes in biotite and chlorite and indicates its alteration genesis. Illite occurs as fibrous within intergranular pore among detrital K-feldspar, quartz and muscovite. Illite consists of 1M polytype suggesting very low- to low-grade metamorphism. The Chemical Index of Alteration ( CIA) indicates intense weathering during the deposition of the shales. Compared with Post-Archean Australian Shales ( PAAS) , there is a slight enrichment in HREE, depletion in LREE and positive Eu anomalies. It is noted that enrichment of total iron has not been observed in the shales more than that of the PAAS and North America Shales ( NASC) and, by extension, implying no anoxia. Transition trace elements ( V, Cr, Co and Ni) show oxidized water column. It is reasonable to infer that neritic-shelf seawater has been oxidized in combination with a stratified model of the Mesoproterozoic Ocean. Meanwhile, contemporaneous clay and shale deposits also indicate intense weathering worldwide and it could be related to variable oxygen contents.

Various types of igneous suites occurred between 930 Ma and 890 Ma in the North China craton are known to represent a large igneous province (UP). However, the magma plumbing system of this LIP and its potential consequence to a breakup event are poorly understood. We report morphology, aystal size distribution of plagioclase, and whole-rock and mineral geochemistry profiles of this LIP represented by the two decoupled mafic sill complexes (Niutishan and Pingshan) in the Xuhuai basin. In terms of petrography and whole-rock geochemistry, unlike the lower-level doleritic Niutishan sill, the Pingshan sill is subdivided into an upper and a lower sequence that meets at a Sandwich Horizon but lacks stratification. The significant En reversals present an almost M-shaped profile that differs from a C-shaped profile as previously revealed in the Niutishan sill. Quantitative textural analyses show relatively strong plagioclase orientation in the lower sequence of the Pingshan sill, which is attributed to magma flow. The Pingshan sill is interpreted to have been constructed as multiple magma injections from crustal magma chambers based on the crystal size distribution and the varied crystallization pressure (5.1-7.5 kbar) of dinopyroxene crystals. Similar to the far-field radiating Dashigou dyke swarm (c. 925 Ma), the Niutishan sill is enriched in incompatible elements, which may represent the initiation of the Xuhuai rifting. However, the depleted features of the diamond-bearing Pingshan sill and the other coeval doleritic sills (916-890 Ma) were probably related to the subsequent process switched from continental rifting to lithospheric rupture in the divergent stage of the Wilson cycle. The occurrence of the intrusive rocks evolving from an early radiating dyke swarm to later sill complexes indicates a time-transgressive change from radial to planar patterns, implying that it was the upwelling asthenospheric plume material, instead of plate boundary processes, governed the initial and early evolution of this intracontinental rift. (C) 2020 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

华北克拉通南缘中元古代早期发育陆源碎屑-碳酸盐岩沉积,豫西地区兵马沟组作为其早期陆源碎屑充填沉积,对于探讨中元古代早期华北克拉通南缘沉积环境演化有重要意义.在野外地质剖面实测基础上,结合岩性及粒度特征划分沉积相,探讨渑池地区兵马沟组沉积环境演化,为华北克拉通南缘中元古代早期沉积环境演化提供约束.豫西渑池地区兵马沟组剖面自下而上主要岩性为含砾砂岩-粉砂岩、泥岩-含砾砂岩,垂向上沉积物粒度特征具粗-细-粗的变化,概率累计曲线揭示其水动力条件先减小后变大,兵马沟组下段为河控三角洲的三角洲平原-三角洲前缘-前三角洲-三角洲前缘亚相,上段为滨海相的临滨-前滨亚相,其代表华北克拉通南缘构造活跃期-稳定盖层沉积期之间初期海进-海退旋回;中元古代早期,华北克拉通南缘表现为北东高南西低的古地形特征,兵马沟组是该时期熊耳群或华北克拉通古老基底遭受快速剥蚀的产物;对比不同地区的兵马沟组沉积特征,其在区域上的沉积差异可能是沉积时间及古地形差异性造成的.渑池地区兵马沟组在该时期仍受华北克拉通熊耳裂谷活动的影响,兵马沟组记录了裂谷盆地充填早期的演化过程,对研究华北克拉通南缘中元古代早期大地构造演化具有重要意义.

The late Mesoproterozoic to Neoproterozoic sedimentary rocks in the southeast North China Craton (NCC) are significant in paleogeographic reconstruction. An integrated approach of field investigation, detrital zircon U-Pb dating, and Lu-Hf isotope analysis reveals essential information on the tectonic-sedimentary evolution of the Xuhuai Basin. New age constraints show that the Xuhuai Basin comprises a lower (Huaihe Group, 1.1-0.9 Ga) and an upper (Langan Group, < 0.82 Ga) successions, with an unconformity between them. The depositional age of the middle to upper part of the Huaihe Group (the Niyuan-Wangshan formations) is limited to 0.97-0.89 Ga. A comparison of regional basin formations suggests that the Xuhuai, Jiaolai, Dalian, and Pyongnam basins belong to the same rift system (the Xuhuai rift system). There was a distinct provenance change from similar to 2.7-2.5 Ga, similar to 2.1 Ga and similar to 1.9 Ga rocks (zircon ages) in the lower part, to 1.8-1.0 Ga in the middle-upper part of the Huaihe Group, and back to similar to 2.7-2.5 Ga, similar to 2.1 Ga and similar to 1.9 Ga rocks in the Langan Group. The similar to 2.7-2.5 Ga, similar to 2.1 Ga, similar to 1.9Ga, and similar to 1.8-1.4 Ga provenances could be from the NCC, while the 1.2-1.0 Ga provenances were possibly from the Grenvillian orogens which could be far or close neighbors of the NCC before 0.9 Ga. While both the 1.4-1.3 Ga and 1.2-1.0 Ga provenances possibly support a North China-Sao Francisco-Congo connection hypothesis, in which the Early Neoproterozoic basins such as the Xuhuai rift basins along the southeastern margin of the NCC, the coeval basins along the eastern and western margins of the Sao Francisco Craton and the west Congo Craton comprise a correlated rift system during 1.1-0.9 Ga.

The architecture of the Archean crust is crucial in understanding the geodynamics of cratonization. The Dharwar Craton in the Indian peninsula is well known for its continuous change of metamorphic grades from granulite facies in the south to amphibolite facies in the middle and greenschist facies in the north. Here the genetic relationship of different units is re-analyzed to decipher the crustal architecture of the craton. The major lithologic unit - the granitoids can be subdivided into TTG, charnockite, Closepet granite and anatectic granites/migmatites. The charnockite near Salem has two types of occurrence: one is massive, garnet-free and plutonic, crystallized at similar to 2560 Ma, and the other is gneissic, garnet-bearing and incipient, metamorphosed at similar to 2490 Ma. Both types are compositionally close to tonalite-granodiorite, and generally show positive Eu-anomalies. A large proportion of zircons of both types show positive epsilon Hf-t values (varying from -3 to + 9), indicating a relatively juvenile parent ( < 2800 Ma). The garnet-bearing charnockite was probably transformed in situ from the lower crust at granulite facies; whereas the garnet-free charnockite represents exotic magmas originated from the lower crust. The Closepet granite is potassium-rich and high in Mg#, and shows negative Eu-anomalies. It was emplaced at 2520-2510 Ma (simultaneous with the garnet-bearing charnockite), and the igneous zircons show negative epsilon Hf-t values ( - 9 to + 1). It likely originated from relatively ancient ( > 2900 Ma) crust at medium-pressure (in the middle crustal level) with significant mantle contribution. The genetic relationship of different units, the spatial age difference of greenstone belts and the spatial variation of metamorphic grade in the Dharwar craton suggest a trinity of Archean crustal architecture ('sandwich' structure), with 2700-2500 Madominated uppercrust, 3400-2900 Ma-dominated middle crust, and similar to 2560 to 2500 Ma anatectic lower crust. This 'sandwich' structure possibly indicates vertical growth of the crust in the Archean. The whole craton was tilted at similar to 2500 Ma with the southern end uplifted the most by an intra-cratonic process, and then it was shaped by later orogenic events resulting in the formation of the dominantly N-S trending structures in the basement.

Xiong'er volcanism and the accompanying sedimentation that occurred along the southern margin of the North China Craton (NCC) are thought to be related to the breakup or outgrowth of the Columbia supercontinent. A series of conglomerates, pebbly sandstones, coarse- to fine-grained sandstones, siltstones, and argillaceous rocks that comprise the Bingmagou Formation unconformably overlie the Paleoproterozoic Xiong'er volcanic rocks, which themselves are unconformably overlain by Mesoproterozoic sediments (Wufoshan and Ruyang Groups) within the southern margin of the NCC. The Bingmagou Formation is considered to be one of the oldest known clastic deposits, providing information on tectonic evolution subsequent to the Xiong'er volcanism. These rocks comprise a fan delta facies sequence and can be divided into fan delta plain, fan delta front, and pro-fan delta subfacies. Detrital zircons from the formation reveal the presence of two major age peaks at ca. 2700 Ma and 2500 Ma, and one minor age peak at ca. 2100 Ma; indicative of an NCC basement provenance. Samples from the Ma'anshan Formation (Wufoshan Group) yield a major age peak at ca. 1850 Ma, a minor peak at ca. 2500 Ma, and include several younger ages between ca. 1698 Ma and 1798 Ma. These ages are indicative of progressive evolution of provenance between the Bingmagou Formation and the overlying Ma'anshan Formation. The geochemistry of Bingmagou Formation sediments is indicative of felsic source rocks with arc-like affinities, which is markedly distinct from the upper groups. Sedimentary facies, regional unconformities, and detrital zircon data may indicate an uplift in the source area.

Two mafic dyke swarms are identified from the Qianli-Helan Mts, one dominated with N-E-trending dykes, namely the Qianlishan swarm, intruded the Paleoproterozoic basement but was unconformably covered by the Precambrian Huangqikou Fm., while another with mostly N-W-trending ones, namely the Helanshan swarm, intruded both the basement and the Huangqikou-Wangquankou Fms. but was covered by the Carboniferous strata. Baddeleyites liberated from one Qianlishan dyke give a SIMS Pb-207/Pb-206 age of 813 +/- 7Ma (MSWD = 0. 63, n = 6), representing the timing of emplacement. Zircons from one Helanshan dyke, however, give the youngest Pb-206/U-238 ages of similar to 370Ma, representing an age of or slightly older than its intrusion. The Qianlishan dykes are tholeiitic, with high TiO2 (2. 7% similar to 3. 7%) and Fe2O3T (13.4% similar to 17. 0%) contents; whereas the Helanshan dykes are (weak) alkaline basalt with low TiO2 (1. 0% similar to 1. 5%) and Fe2O3T (5. 5% similar to 12. 4%) contents. Both swarms show enriched light rare earth elements and large ion lithophile elements but depleted high field strength elements, which are more prominent for the Helanshan swarm than the Qianlishan (e.g., (La/Yb)(N) are 2. 0 similar to 5. 5 for the Helanshan but 1. 9 similar to 2. 4 for the Qianlishan dykes). These features indicate that the parental magmas were probably both from a metasomatized lithospheric mantle or/and they were contaminated by the crust. The unconformable relationship of the Huangqikou, Wangquankou and Zhengmuguan Fms. related to the Qianlishan dykes and their relationship with the Cambrian strata indicate that these strata deposited during 810 similar to 541Ma. The basement of the Qianli-Helan Mts region belongs to the western North China Craton. It borders the Alxa block to the west, whose relationship with the craton is in debating. Based on the similarity of basement and the coeval and chemically similar igneous associations in the two regions (e.g., the 830 similar to 810Ma Langshan Group bimodal volcanics and Jinchuan mafic-ultramafic intrusions in the Alxa block), it is preferred here that the Alxa block was also a part of the craton as the basement of the Qianli-Helan Mts region, and both regions experienced extension rifting event during the Middle Neoproterozoic.

Recently,an Early Neoproterozoic North China-S(a)o Francisco connection model has been proposed;however,it awaits further evidence.In this paper,Precambrian geological records of the two cratons have been summarized and compared,aiming to provide clues to evaluate the above model.Major crustal events peaked at ～ 2.7 Ga in both cratons;however,there were distinct ～ 2.5 Ga crustal growth and reworking events in the North China Craton,which are seemly absent in the S(a)o Francisco Craton.There are only a few 2.4 ～ 2.2 Ga volcanics and plutons in the North China Craton,comparing with widespread rifting-related volcanicsedimentary formations and plutons at ～ 2.1 Ga and arc-related igneous series and ultra-high temperature metamorphism at ～2.0～1.9 Ga,which resulted in the amalgamation of the eastern North China Craton and the western North China Craton to form the unified North China paleocontinent.As for the S（a）o Francisco Craton,there is a long-lived magmatism event along both the northern and southern margins of the block during 2.4 ～ 2.0 Ga,including ～ 2.0 Ga ultra-high temperature metamorphism.It is likely that both cratons have experienced ～ 2.0 ～ 1.9 Ga arc-events except that the peak metamorphism is slightly earlier in the S(a)o Francisco Craton than that in the North China Craton.There are several generations of 1.8 ～ 0.8 Ga major dyke swarms in both cratons,and some of these are coeval,e.g.,～ 1.75 Ga,～ 1.7 Ga,and ～ 0.92 Ga dyke swarms;however,there are ～ 1.3 ～ 1.2 Ga sills/dyke swarms in the North China Craton but ～1.5 Ga dyke swarms in the S~o Francisco Craton.There are 1.8～0.8 Ga (volanic-) sedimentary formations in both cratons:they comprise of quartz-sandstone-dominated clastic rocks with minor carbonates for 1.8 ～ 1.6 Ga and 1.4 ～ 1.2 Ga sequences,and clastic sediments and carbonates for 1.0～0.8 Ga sequences;however few 1.2 ～ 1.0 Ga records or sequence (s) have been confirmed.There is a 1.6～ 1.4 Ga carbonate-dominated sequence in the North China Craton but a clastic sediments-dominated suite in the S(a)o Francisco Craton.It needs to be mentioned that there are plenty of ～ 1.5 Ga detrital zircons in the Neoproterozoic strata in the North China Craton,of which rare coeval igneous rocks have been reported,comparing with a distinct igneous event peak in the S(a)o Francisco Craton.Both cratons developed Archean-Paleoproteorzoic banded iron formation-related iron deposits,Paleoproterozoic graphite ore deposits,and M eso-Neoproterozoic volcanic-sediments-related sulphide lead-zinc ore deposits.Paleoproteroizc boron and magnesite deposits,and Mesoproterozoic carbonatite-related rare earth element ore deposits were developed in the North China Craton,but not in the S(a)o Francisco Craton;on the other hand,greenstone belt-type gold and nickel deposits,as well as emerald gem deposits are important in the S(a)o Francisco Craton but not in the North China Craton.During ～ 0.7 ～ 0.5 Ga,the S(a)o Francisco Craton was surrounded by the Pan-Africa orogenic;whereas it seems absent in the North China Craton.During Phanerozoic,the S(a)o Francisco Craton was stable,except that its broke away from the Congo Craton during the Mesozoic;while the North China Craton has experienced strong tectno-magmatic event during Mesozoic.More work based on detailed geological comparison and paleo-magnetic poles is needed to confirm their neighbourhood,focusing especially on the ～ 2.0 ～ 1.9 Ga igneousmetamoprhic (orogenic) event,the ～ 1.8 ～ 1.7 Ga igneous-sedimentation (rifting) event,and the ～ 0.9 Ga igneous-sedimentation (rifting) event.Nevertheless,if the two blocks were neighbours,the eastsouthern margin of the North China Craton and the southern margin of the S(a)o Francisco Craton are possible linking positions for their similar and continous geology.

The Niutishan sill, one of the similar to 900 Ma mafic sills in Xuzhou (Jiangsu province, North China), has a thickness of similar to 30 m. We have identified chemical parameters that define three differentiated interlayers from thirty-eight samples in a similar to 22 m profile. The sill reveals a succession consisting of an upper border zone of fine-grained dolerite (UZ), a middle zone of quartz-bearing gabbro (MZ), a coarse-grained apatite-enriched gabbro (LZc), a layer of Fe-Ti oxide-enriched gabbro (LZb) and a deeper medium-grained massive gabbro (LZa) at the bottom of the lower zone, capped by an uppermost chilled margin (CM) of plagioclase-clinopyroxene-porphyritic dolerite. Its significantly differentiated interlayers offer an opportunity to investigate the petrogenesis of high-Fe-Ti gabbro. The chilled margin composition suggests a highly evolved ferro-basaltic parental magma (whole-rock Mg#: 39, with similar to 2.9 wt% TiO2 and similar to 14.2 wt% FeOt), which likely represents a residual magma derived from a deep-seated magma chamber after significant removal of olivine. The internal compositional variation was controlled by fractional crystallisation with successive presence of plagioclase and Fe-poor clinopyroxene, followed by Fe-Ti oxides plus Fe-rich clinopyroxene, and finally apatite and albite-oligoclase. This sequence is consistent with the result of thermodynamic modelling of MELTS at a low H2O content of similar to-0.2 wt% and in a temperature range from 1200 to 780 degrees C and at a pressure of 70 MPa. The saturation of clinopyroxene before Fe-Ti oxides in liquids is interpreted to imply low-fO(2) and water-unsaturated conditions, which led the residual magma to an Fe-Ti-enriched trend. After the saturation and mechanical settling of clinopyroxene primocrysts from the parental magma, large amounts of Fe-Ti oxides crystallised from the evolved Fe-Ti-rich melt. Further crystallisation and solidification of the crystal mush led to the formation of the major Fe-Ti oxide-rich layer and expelled interstitial melt upward to mix with the more evolved residual melts, leading to the saturation of apatite. Meanwhile, the residual melts gradually tended to Si enrichment, which matches the observed compositions (enriched incompatible elements) of naturally occurring quartz- gabbro in the MZ. As a result, viscosity would increase, trapping highly evolved melts and impeding liquid separation, as exhibited by the silicic mesostasis of graphic intergrowths of quartz and alkali feldspar, and occasionally calcite. This sill is also characterized by considerable amounts of titanite at the bottoms of the UZ and LZ, which was likely formed during the late evolutionary stages as products of reaction between the primary Ti-rich minerals and a late igneous fluid/melt at temperature near 584 degrees C. The F-rich and Cl-poor apatite (X-F > 0.95) and Ti-rich magnetite (7.2-9.7 wt% Ti) from Fe-Ti (P)-rich layers indicate a magmatic origin from high-temperature Fe-Ti-rich melts. It is thus concluded that the significantly differentiated Niutishan sill was formed by the combined processes of fractionation, accumulation and compaction under water-unsaturated and low-fO(2) conditions, which most likely occurred in an intra-continental rather than a subduction-related environment. Further synthetic analysis suggests conclusion that this magmatism may record a break-up event. (C) 2018 Elsevier B.V. All rights reserved.

In this article, the geochemical data of a ~900 Ma mafic sill from Xuzhou, North China are reported. These datasets include 37 whole-rock major and trace element data, and 21 major element data on plagioclase, 20 major element data on clinopyroxene crystals, 10 major element data on apatite crystals, 7 major element data of preserved coexisting titano-magnetite and ilmenite grains, 36 major element data on different types of ilmenite crystals, 13 major element and 11 trace element data on titanite. These data are associated with Su et al. “Petrogenesis of a ~900 Ma mafic sill from Xuzhou, North China: Implications for the genesis of Fe-Ti-rich rocks” (Su et al., 2018), and in which their characters and variations were interpreted and discussed.