Precambrian Research最新文献

{"title":"Synthesis of structure and tectonic evolution of Meso-Neoproterozoic Vindhyan Basin, India using geophysical and geological data: A plate tectonic perspective","authors":"V. Vijaya Rao ,&nbsp;K. Laxminarayana ,&nbsp;Biswajit Mandal ,&nbsp;P. Karuppannan ,&nbsp;Prakash Kumar","doi":"10.1016/j.precamres.2025.107787","DOIUrl":"10.1016/j.precamres.2025.107787","url":null,"abstract":"<div><div>The Origin of the Mesoproterozoic intracratonic basins is not well understood compared with the Phanerozoic basins of the world. The present investigation attempts to comprehend the evolution of one such basin of Indian origin and relates its tectonic events with the amalgamation and fragmentation of supercontinents. The Vindhyan basin, India, is one of the largest Meso-Neoproterozoic basins in the world and has probable hydrocarbon potential. It is mostly undeformed and unmetamorphosed, except at the margins. Seismic reflection and refraction, gravity, and well data are integrated with geology, geochemistry, and geochronological data to understand the tectonic evolution of the region. A basement ridge identified in the study divides the basin into two parts: the Chambal valley in NW and Son-valley in SE, which contain 5.8 km and 4.5 km thick Proterozoic sediments. A collisional suture and an arc signature are identified at the Narmada-Son Lineament zone. We suggest a dual-stage foreland basin system has evolved due to the subduction of the leading edge of the Bundelkhand Craton beneath the Mewar and Bastar Cratons around 1.8 Ga. Subsequent collisions of these cratons resulted in the evolution of Aravalli and Satpura orogens. Nature of basin boundary faults, crustal-scale Great Boundary Thrust in NW, and the Narmada-Son lineament in SE, formed during the collision processes are discussed. Far-field plate boundary forces developed due to subduction-collision processes likely influenced the evolution of the basins subsequent to foreland setup. Presence of the Vindhyan Sea and tilting of the continental block to northeast during 1200–800 Ma resulted in common Upper Vindhyan sedimentation in the Chambal- and Son-Valley Basin, including the Ganga Basin in NE. Present study suggests extension of the Vindhyan Basin beneath the Ganga basin. We propose an evolutionary model in a plate tectonic framework that explains several aspects of the basin, including the formation of basin-central ridge during Proterozoic subduction process. The 2.5 Ga and 2.2 Ga events of the region are cotemporaneous with the assembly and breakup of Neoarchean supercontinent Kenorland. Timings of Lower and Upper Vindhyan sedimentation and termination broadly coincide with the assembly and breakup of Paleo- and Mesoproterozoic supercontinents Columbia and Rodinia.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107787"},"PeriodicalIF":3.2,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The significance of Archean sanukitoids in the cratonization process: The example of the Barlow pluton, between the Abitibi and Opatica subprovinces, Superior Craton, Quebec","authors":"Esther M.-A. Bou ,&nbsp;Dominique Genna ,&nbsp;Michel Jébrak ,&nbsp;Lucie Mathieu ,&nbsp;Jeffrey H. Marsh","doi":"10.1016/j.precamres.2025.107789","DOIUrl":"10.1016/j.precamres.2025.107789","url":null,"abstract":"<div><div>Much debate surrounds Archean crustal growth and its evolution, as well as processes leading to the stabilization of the crust (cratonization). The Barlow pluton is a late-tectonic granitoid that intrudes into the boundary between the Abitibi greenstone belt and the Opatica plutonic belt (Québec, Canada), two subprovinces that make up the southeastern part of the Superior Craton. The Barlow pluton and the Maaskitkuu tonalite, one of its host rocks, are useful to improve the understanding of tectonic and magmatic processes along the margins of subprovinces in Archean cratons. Here, whole-rock analyses, dating (U-Pb on zircon) and barometry on amphibole are used to define the petrogenesis of these two plutons. The older Maaskitkuu tonalite (ca. 2705 <!--> <!-->Ma) belongs to a Tonalite-Trondhjemite-Granodiorite (TTG) intrusive suite and has a high Sr/Y ratio. The Barlow pluton (ca. 2696 <!--> <!-->Ma) belongs to the sanukitoid group. The Maaskitkuu tonalite emplaced 10 km deeper than the Barlow pluton, pointing to the exhumation of 10 km of rocks in about 11 Ma, corresponding to an exhumation rate of 1.37 mm/yr. When combined with previous structural and seismic studies, the observations support an imbrication of terranes farther to the north and the south to explain the arrangement of both subprovinces, marked by a transcrustal structure. This structure allows melts from the lower crust and the metasomatized mantle to ascend toward the upper crust promoting the cratonization.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107789"},"PeriodicalIF":3.2,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detrital zircon record of shutdown and migration of Cadomian volcanic arcs in the Bohemian Massif, with implications for Ediacaran to early Cambrian plate kinematics","authors":"Jiří Žák ,&nbsp;Martin Svojtka ,&nbsp;R. Damian Nance ,&nbsp;J. Brendan Murphy","doi":"10.1016/j.precamres.2025.107786","DOIUrl":"10.1016/j.precamres.2025.107786","url":null,"abstract":"<div><div>This paper presents new U–Pb detrital zircon ages that constrain the age of deposition of a Cadomian intra-arc succession (Štěchovice Group in the Bohemian Massif) overlying one of the best preserved volcanic arcs (Davle volcanic complex) of the Avalonian–Cadomian belt, which rimmed the northern margin of Gondwana in the Neoproterozoic to Cambrian. The record of this active margin is well preserved, but how subduction terminated along it remains a matter of debate. Our new data from the Štěchovice Group suggest abrupt arc termination in this region followed by turbidite deposition in a short-lived basin at around 570 Ma. However, the ages of voluminous arc-derived graywackes in a neighbouring accretionary wedge suggest arc magmatism continued until ca. 527 Ma. Regional gravity highs inboard of the Davle volcanic arc indicate the presence of unexposed dense rocks that may represent the missing, post-570 Ma Cadomian arc. If so, the arc axis migrated landward, consistent with the presence of intrusive boninites within the older Davle arc, which would have then occupied a fore-arc position and must have been eroded and submerged prior to the deposition of Štěchovice Group. We suggest that the inferred arc migration beginning at around 570 Ma occurred in response to slab flattening due to the arrival of hotter oceanic lithosphere, perhaps in the form of a spreading ridge that migrated eastwards along the Avalonian–Cadomian active margin leaving a dextral transform margin in its wake. Such a ridge is thought to have first impinged on Avalonia to the west at around 600 Ma and later caused arc extinction in the Armorican Massif and Saxothuringian unit at around 570 Ma, with arc migration in the Bohemian Massif at about the same time. The ridge–trench interaction is then inferred for the Bohemian Massif in the early to middle Cambrian (at ca. 527–515 Ma), consistent with ongoing subduction in the more easterly proto-Alps until the mid-Ordovician. How the inferred migration of the ridge–trench–transform system was linked to the movement of Baltica, and whether it could have brought Baltica close enough to supply Mesoproterozoic detritus to Gondwana’s northern periphery remain open questions.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107786"},"PeriodicalIF":3.2,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochronology of the Vindhyan Supergroup: Implications for the closure of the Proterozoic basins of India","authors":"Bivin G. George ,&nbsp;Jyotiranjan S. Ray ,&nbsp;Milan K. Mahala ,&nbsp;J. Amal Dev ,&nbsp;J.K. Tomson ,&nbsp;J. Haripriya ,&nbsp;Alok Kumar","doi":"10.1016/j.precamres.2025.107790","DOIUrl":"10.1016/j.precamres.2025.107790","url":null,"abstract":"<div><div>The sediments of the Vindhyan Supergroup, deposited in the largest Proterozoic basin of India, are known to have recorded changes in the seawater chemistry, changes in global climate, and one of the earliest fossil records of multicellular eukaryotes. These rocks, particularly the upper part of the sequence, are also home to some of the most controversial fossils of the Neoproterozoic lifeforms. Despite receiving enough attention, the evolutionary timeline of the upper part of the supergroup and the timing of the closure of the Vindhyan Basin remained uncertain. Issues related to the stratigraphic correlation within the basin, temporal relation with other Proterozoic basins of India, and validity of the evidence of global events reported from the basin remained unresolved. Here, we present results of Pb-Pb dating of carbonate formations and detrital zircon U-Pb dating of sandstone formations of the upper Vindhyans from the western and the eastern sectors of the basin to resolve some of the above chronological issues. Based on Pb-Pb isochron ages, we establish that the Bhander Limestone formation in the Son Valley sector (eastern) was deposited in two major periods: one at 874 ± 77 (2σ) Ma and the other at 768 ± 36 (2σ) Ma, with breaks in sedimentation in between. Based on the Pb-Pb isochron age of 871 ± 78 (2 σ) Ma, the Balwan Limestone, the topmost carbonate formation in the Rajasthan sector (western), is proposed to be laterally correlatable to the Bhander Limestone in the Son Valley. The Lakheri Limestone formation in Rajasthan is deemed to have no correlatable carbonate formation in the Son Valley. The maximum depositional ages of sandstone formations, determined from zircon U-Pb data, suggest that the top part of the Vindhyan Supergroup is younger than 830 Ma. Our results establish that the closure of the Vindhyan Basin happened sometime during the late Tonian. Therefore, these successions are unlikely to contain evidence of the Cryogenian glaciations or the Ediacaran life. This new age information puts the Vindhyan Basin in the league of at least two other Proterozoic basins of India (i.e., Marwar and Kaladgi), which, contrary to general belief, had remained active during the Neoproterozoic (&lt; 1000 Ma). We did not find any evidence of coevolution of the Vindhyan Basin with other Proterozoic basins of India.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107790"},"PeriodicalIF":3.2,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143799907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zircon U-Pb age and petrogenetic constraints on granitic magmatism from the southwestern Chhotanagpur Granite Gneiss Complex: Implications for Proterozoic crustal growth in the Central India","authors":"Mohammad Qasim ,&nbsp;Satya Narayana Mahapatro ,&nbsp;Sameer Ranjan ,&nbsp;Ajay Dev Asokan ,&nbsp;D. Srinivasa Sarma ,&nbsp;M. Ram Mohan","doi":"10.1016/j.precamres.2025.107783","DOIUrl":"10.1016/j.precamres.2025.107783","url":null,"abstract":"<div><div>The Chhotanagpur Granite Gneiss Complex (CGGC) is an integral part of the Central Indian Tectonic Zone (CITZ), which records the Proterozoic tectono-thermal evolution of the Indian Shield. In this study, we carried out detailed petrography, bulk rock geochemistry, Nd isotopic studies and U-Pb zircon geochronology for granitoids from the southwestern CGGC. Four episodes of granitic magmatism from this area are documented, which are (i) c. 1660 Ma granite gneiss, (ii) c. 1565 Ma foliated granite, (iii) c. 1462 Ma porphyritic granite, and (iv) c. 1140 Ma equigranular granite. The c. 1660 Ma granite gneisses are migmatitic, I-type, and their Nd isotopic compositions are mildly sub-chondritic (εNd_(t) = –0.90 to –2.55). The geochemical characteristics suggest them sourced from mafic to intermediate sources with inputs from pre-existing crustal rocks. The c. 1565 Ma foliated granites are peraluminous, S-type, and have evolved Nd isotopic composition (εNd_(t) = –2.40 to –4.69) with Mesoarchean model ages, which suggests their derivation from a metasedimentary source. The c. 1462 Ma porphyritic granite and c. 1140 Ma equigranular granites have geochemical attributes similar to the A₂-type granites. The strongly evolved Nd isotopic signatures (εNd_(t) = –4.39 to –5.38 and –6.81 to –8.38) for porphyritic granite and equigranular granite, respectively, suggest inputs from both enriched mantle and pre-existing crustal sources. Based on these findings, the Proterozoic evolution of the CGGC can be broadly divided into four stages, with stages 1 and 2 corresponding to c. 1660–1565 Ma arc magmatism, where the granite gneisses were emplaced, followed by the emplacement of foliated granites in the waning stage. Stage 3 corresponds to the emplacement of c. 1462 Ma A-type granites associated with the extensional environment. Stage 4 is associated with post-collisional setting where the c. 1140 Ma equigranular granites were formed. The presence of recrystallized zircon domains with c. 900–1000 Ma in all granitoid variants supports widespread Grenvillian high-grade metamorphism in the CITZ. These results suggest that granitoids from the southwestern CGGC exhibit a transitional tectonic regime with an initial arc followed by extensional tectonics, culminating in a post-collisional environment, possibly linked with the breakup of Columbia and the amalgamation of Rodinia supercontinents.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107783"},"PeriodicalIF":3.2,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The formation of a unified basement of the Yangtze Craton","authors":"Liang Zhang ,&nbsp;Shao-Bing Zhang","doi":"10.1016/j.precamres.2025.107770","DOIUrl":"10.1016/j.precamres.2025.107770","url":null,"abstract":"<div><div>The Yangtze Craton has a long evolution history since the Eoarchean. With the increasing number of studies on the Yangtze Craton, ten Archean-Paleoproterozoic basements, separated from each other, have been identified. These basements may represent independent microcontinental blocks before they were amalgamated into a unified basement. To decipher their affinities with each other and when these microcontinental blocks joined together to form the basement of the Yangtze Craton, we compiled the Archean-Mesoproterozoic magmatic and metamorphic events and zircon U-Pb ages with Hf isotope data of magmatic rocks in these basements. Magmatic activities of basements in the Yangtze Craton mainly occurred within nine periods: approximately 3.7 Ga, 3.1–2.9 Ga, 2.9–2.7 Ga, 2.7–2.6 Ga, 2.5–2.4 Ga, 2.4–2.2 Ga, 2.1–1.9 Ga, 1.9–1.7 Ga, 1.7–1.6 Ga. By comparing the timings of tectono-thermal events and calculating the likeness of igneous zircon Hf isotopes between them, we reconstructed the assembly history of these microcontinental blocks and the formation time of the unified basement of the Yangtze Craton. The amalgamation history can be briefly summarized as: Yangkou was assembled with Dabie at ca. 3.7 Ga; Cuoke was merged with Phan Si Pan during 3.1–2.9 Ga to form the proto-south Yangtze Craton; Zhongxiang and Kongling were assembled during 2.9–2.8 Ga; Yangkou-Dabie, Zhongxiang-Kongling, and Yudongzi were assembled during 2.7–2.6 Ga; Feidong and Douling joined the Yangkou-Dabie-Zhongxiang-Kongling-Yudongzi assemblage during 2.5–2.4 Ga, constituting the proto-north Yangtze Craton. The coeval development of ca. 2.0 Ga metamorphism in the proto-south and the proto-north Yangtze Craton suggests that the amalgamation of the Yangtze Craton may have occurred as early as approximately 2.0 Ga. The occurrence of 1.9–1.7 Ga A-type granites and mafic dykes indicative of extension in both the northern and southwestern blocks marks the final assembly of the Yangtze Craton. The development of late Paleoproterozoic-Mesoproterozoic sedimentary strata with sporadic interlayered mafic volcanics in most parts of the Yangtze Craton suggests the stability of the Yangtze Craton. Based on the aforementioned evidence, we propose that a unified basement of the Yangtze Craton was formed no later than the late Paleoproterozoic, coeval with the final assembly of the supercontinent Columbia (Nuna).</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107770"},"PeriodicalIF":3.2,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tectonic evolution of the crustal section of the Neoproterozoic Jabal Ess ophiolite-arc complex, Midyan terrane, NW Arabian Shield","authors":"Scott A. Whattam ,&nbsp;Faris Sulistyohariyanto ,&nbsp;Keewook Yi ,&nbsp;Mutasim Osman ,&nbsp;Oktarian Iskandar ,&nbsp;Jieun Seo","doi":"10.1016/j.precamres.2025.107765","DOIUrl":"10.1016/j.precamres.2025.107765","url":null,"abstract":"<div><div>The Jabal Ess ophiolite arc complex (JEOA) comprises basalt and basaltic andesite lavas and dykes and rare gabbros that range from MORB- and Izu Bonin Marianas forearc basalt (IBM FAB)-like to volcanic arc basalt-like but also comprise high-Mg andesite (HMA) and low-Si boninite (LSB); post-ophiolite formation granitoids intrude the ophiolite complex. Though the mafic rocks have major oxide compositional characteristics similar to MORB and IBM FAB, these mafic rocks exhibit prominent primitive mantle normalized negative Nb/Nb* anomalies and HFSE concentrations that range to much lower than MORB. We posit that the Jabal Ess ophiolite formed in adherence to the subduction initiation rule (i.e., MORB-like lavas followed by HMA and LSB) which is at least partially verified by the fact that LSB diabase are intrusive into lowermost peridotite. U-Pb SHRIMP ages of a lone rhyolite and two granites that intrude ophiolite mafic rocks are 687.6 ± 6.5 Ma and 699.0 ± 6.3 to 702.9 ± 6.2 Ma, respectively, and represent post-collisional granitoids that formed during collision of the Hijaz and Midyan terranes which aided in stitching of the 701–695 Ma Yanbu suture zone.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107765"},"PeriodicalIF":3.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence for a Proterozoic carbonatite system in the Mount Isa Province, Australia","authors":"Alex Brown ,&nbsp;Carl Spandler ,&nbsp;Thomas G. Blenkinsop","doi":"10.1016/j.precamres.2025.107784","DOIUrl":"10.1016/j.precamres.2025.107784","url":null,"abstract":"<div><div>Carbonatites are indicators of mantle processes, and they are economically important because of their association with rare earth element (REE), niobium and base metal deposits. Carbonatites and their associated lithologies (i.e. the carbonatite system) have not previously been identified in eastern Australia. We describe veins of dolomite calcite carbonatite, fenites and antiskarn, glimmerite, and alkali pegmatite from the Tommy Creek Domain, of the Eastern Subprovince of the Mount Isa Province (NW Queensland), that constitute a carbonatite system. The system can be identified from field relationships, geochronology, zircon trace elements, and stable and radiogenic isotopes. The emplacement of the carbonatite system coincided temporarily and spatially with regional hydrothermal alteration at ca. 1650 Ma in the Eastern Subprovince, which also has mantle isotopic affinities and is located above the boundary between thin and thick continental lithosphere.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107784"},"PeriodicalIF":3.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New geochronological evidences and diverse arc-related meta-volcanic rock suits from the Northern Liaoning terrane, North China Craton","authors":"Rongrong Guo ,&nbsp;Yang Xiao ,&nbsp;Changming Wei ,&nbsp;Ming Yan ,&nbsp;Ningfeng Du","doi":"10.1016/j.precamres.2025.107755","DOIUrl":"10.1016/j.precamres.2025.107755","url":null,"abstract":"<div><div>The Northern Liaoning terrane locates at the northeastern margin of the North China Craton (NCC). Two debatable tectonic mechanisms, plate tectonic vs. plume/sagduction, were interpreted to dominate the late Neoarchean Northern Liaoning terrane. Besides, ∼2.57–2.51 Ga supracrustal rocks occur layered or as enclaves within ∼ 2.59–2.50 Ga TTG and potassium-rich granitoid gneisses. This is a logical contradiction that ‘young’ enclaves expose within ‘older’ wall rocks. In this study, new zircon U-Pb dating results exhibit that protoliths for these <em>meta</em>-volcanic rocks in the Huiyuan area, north of the Northern Liaoning terrane, crystallized at ∼ 2.61 Ga and underwent metamorphisms at ∼ 2.54–2.48 Ga. The real crystallization ages for reported metavolcanic rocks in the Northern Liaoning terrane were probably highly underestimated.</div><div>In this contribution, garnet–pyroxene amphibolite, amphibolite and (biotite) amphibole gneiss were interbedded and exhibit geochemical affinities to Nb-enriched basalt (NEB), tholeiite and andesite, respectively. NEB exhibits abnormally high Nb, TiO₂ and (Nb/La)_PM values, fractionated REE patterns, and negligible Nb, Ta and Ti anomalies, which was derived from partial melting of slab melts metasomatized mantle wedge with Nb-bearing minerals (i.e., amphibole). Tholeiites yield flat REE patterns, enrichments of LILEs, and depletions of Nb and Zr, which are comparable to primitive arc basalt and interpreted as partial melting of sub-arc mantle wedge previously metasomatized by limited subducted slab-derived fluids. Andesites give fractionated REE patterns and negative HFSE anomalies, among which several andesites are akin to Phanerozoic high-magnesium andesite (HMA), with high MgO, Mg^#, Cr and Ni values, and were generated by interactions between subducted slab-derived melts and sub-arc mantle wedge. Remained normal andesites were hybrids of crustal melts and mantle-derived basaltic melts. Taken together, ∼2.61 Ga NEB, andesite (including HMA samples) and primitive arc basalt associations point to a subduction tectonic mechanism developing in the Northern Liaoning terrane. Plume and subduction mechanisms are not mutually exclusive. More precise spatial and temporal distributions effected by plume and subduction, respectively, and how they interact with each other, need to be further studied.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107755"},"PeriodicalIF":3.2,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-resolution chemostratigraphy reveals a large δ13C gradient in the ∼ 1.56 Ga redox-stratified ocean","authors":"Jin Luo ,&nbsp;Simon W. Poulton ,&nbsp;Bo Chen ,&nbsp;Lanyun Miao ,&nbsp;Kai Chen ,&nbsp;Haijing Sun ,&nbsp;Zhenfei Wang ,&nbsp;Guoxiang Li ,&nbsp;Maoyan Zhu","doi":"10.1016/j.precamres.2025.107785","DOIUrl":"10.1016/j.precamres.2025.107785","url":null,"abstract":"<div><div>Reports of decimeter-scale eukaryotic fossils and oxygenation events in the Gaoyuzhuang Formation (∼1.56 Ga, North China Craton) have provided valuable insight into potential links between life and the environment during the early Mesoproterozoic. However, the detailed nature of this relationship remains unclear, partly due to a limited basin-wide stratigraphic framework. Here, we present high-resolution carbon isotope compositions for carbonate and organic matter (δ¹³C_carb and δ¹³C_org) in two fossil-hosting sections, representing shallow and deeper water settings, to calibrate the timing of marine oxygenation and eukaryotic evolution, and to reveal coeval carbon cycle dynamics. Our high-resolution data display a dynamic δ¹³C_carb pattern with four perturbations in Gaoyuzhuang members III-IV, and suggest a causal link between oxygenation and eukaryotic evolution during the second perturbation. The δ¹³C_carb values exhibit a narrow range, but a distinct ∼ 2.5 ‰ isotopic gradient exists between shallow and deeper water during the third perturbation. By contrast, δ¹³C_org values reflect a more stable, but larger, isotopic gradient (∼7‰), implying decoupling of the carbon isotopic system. We propose that the δ¹³C_org compositions of shallow and deeper waters were controlled by specific microbial communities in a redox-stratified water column and a larger deep-ocean DOC reservoir, whereas δ¹³C_carb sensitivity was buffered by a large DIC reservoir. Our modeling also highlights that the coeval oxygenation events were able to drive the observed short-term δ¹³C_carb gradient during the third perturbation. Our findings reveal a direct relationship between environmental change and eukaryotic evolution, with implications for understanding Mesoproterozoic carbon cycle dynamics and paleo-redox conditions.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107785"},"PeriodicalIF":3.2,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}