Precambrian Research最新文献

{"title":"Evolution and innovation of the metazoan burrowing behaviour from Ediacaran-Cambrian transition, eastern Yunnan","authors":"Da Li ,&nbsp;Man Li ,&nbsp;Yongan Qi ,&nbsp;Guochun Zhao ,&nbsp;Jian Fu ,&nbsp;Fuqiang Guo ,&nbsp;Chengjun Zhang ,&nbsp;Jianyu Guan ,&nbsp;Shishan Zhang","doi":"10.1016/j.precamres.2025.107796","DOIUrl":"10.1016/j.precamres.2025.107796","url":null,"abstract":"<div><div>The Precambrian–Cambrian transition represents a pivotal interval in Earth’s evolutionary history, marked by the demise of Ediacaran biota and the subsequent radiation of bilaterian organisms during the Cambrian Explosion. This study presents an integrated ichnological and sedimentological analysis of trace fossils across the Precambrian–Cambrian boundary interval in eastern Yunnan, South China, with the aim of reconstructing paleoecological dynamics and behavioral evolution during this critical transitional phase.Ichnotaxonomic diversity, architectural complexity, and tiering structure reveal a progressive intensification of metazoan–substrate interactions through the late Ediacaran. Trace fossils from this interval are predominantly horizontal and exhibit morphologies consistent with undermat-mining behaviors, indicating that benthic organisms were largely restricted to the mat-substrate interface. However, rare but distinct vertical burrows suggest the incipient development of exploratory and infaunal lifestyles.With the onset of the Cambrian, there is a notable increase in ichnodiversity, behavioral complexity, and substrate utilization, reflecting enhanced metazoan motility and ecological specialization. This period coincides with a shift from microbial-mat-dominated substrates to mixed-layer systems, driven by increasing bioturbation intensity. By Cambrian Stage 2, widespread bioturbation led to the progressive disruption of microbial mats and facilitated more extensive exploitation of three-dimensional ecological space.Benthic communities expanded their spatial occupation from surficial and semi-infaunal tiers into deeper substrate horizons, promoting greater ecological stratification and trophic complexity. These paleoecological transformations culminated in the replacement of Neoproterozoic-style matgrounds by Phanerozoic-type mix-grounds, representing a fundamental reorganization of marine ecosystems and a major milestone in the early ecosystem evolution of benthic communities.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"423 ","pages":"Article 107796"},"PeriodicalIF":3.2,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948584","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":"Debunking the myth of a single Iron Ore Group in the Singhbhum Craton, India","authors":"Jaganmoy Jodder ,&nbsp;Axel Hofmann ,&nbsp;Marlina A. Elburg ,&nbsp;Rebeun Ngobeli ,&nbsp;Trond H. Torsvik","doi":"10.1016/j.precamres.2025.107800","DOIUrl":"10.1016/j.precamres.2025.107800","url":null,"abstract":"<div><div>Archaean cratonic cover successions with well-preserved banded iron-formations (BIF) and shales provide a crucial window into early Earth surface processes. Here, we report on the intra-cratonic volcano-sedimentary sequences of the Koira and Simlipal groups of the Singhbhum Craton of India, regarded by some to be equivalent of Palaeoarchaean BIF-bearing greenstone successions collectively referred to as Iron Ore Group. However, field relationships and precise LA-Q-ICP-MS U-Pb detrital zircon ages from basal siliciclastic units of the Koira Group, non-conformably overlying Palaeo- to Mesoarchaean granitoid-greenstone basement, record a maximum depositional age of ca. 2.86 Ga. Sandstone intercalated with shale and banded iron formation of the Koira Group yields a maximum depositional age of ca. 2.68 Ga, placing the deposition of the iron formation and correlative units firmly into the Neoarchaean. The data therefore call for separate BIF–bearing sequences of Palaeoarchaean and Neoarchaean age, thus debunking the persistent myth of a single Iron Ore Group in the Singhbhum Craton of India. It further underscores similarities in the evolution of the Kaapvaal, Pilbara and Singhbhum cratons, which emerged in Mesoarchaean times to accommodate shallow-marine strata and sub-aerial flood basalts in an intra-continental setting.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"423 ","pages":"Article 107800"},"PeriodicalIF":3.2,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924232","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":"Occurrence of Nb, Ta, and Cs in Precambrian low-grade metamorphic basement rocks in South China: Mineralogical characterization and petrogenetic significance","authors":"Yuli Yuan,&nbsp;He Zhang,&nbsp;Yuanfeng Cai,&nbsp;Xi Zhao,&nbsp;Yuguan Pan,&nbsp;Jinhai Yu","doi":"10.1016/j.precamres.2025.107794","DOIUrl":"10.1016/j.precamres.2025.107794","url":null,"abstract":"<div><div>This paper describes the occurrence of Nb, Ta, and Cs in Precambrian low-grade metamorphic basement rocks in South China. The occurrence of Nb, Ta, and Cs in slates was investigated using a combination of chemical and structural characterization techniques (i.e., trace element geochemistry, electron probe microanalysis, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy). Cs⁺ is hosted in either Cs-bearing sericite. Nb⁵⁺ and Ta⁵⁺ occur mainly in the octahedral sites of sericite and Fe-chlorite. During prograde metamorphism, the Cs⁺, Nb⁵⁺, and Ta⁵⁺ ions that were originally adsorbed on the surfaces of kaolinite and montmorillonite were incorporated into the lattice of phyllosilicate minerals such as sericite and Fe-chlorite. Crystal-chemical calculations reveal a clear compositional trend from Al- to Fe-chlorite with increasing temperature, along with an increase in Nb contents. Our results provide direct mineralogical evidence for the pre-enrichment of ore-forming elements in the basement rocks of South China, as well as in similar settings worldwide; e.g., the Northern Cape and southern Ghana Li-Cs-Ta deposits in Paleoproterozoic shales of the Wa-Lawra Belt. The Nb- and Ta-bearing Fe-chlorite and Cs-bearing sericite are examples of new occurrences of critical metals in low-grade metamorphic rocks.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"423 ","pages":"Article 107794"},"PeriodicalIF":3.2,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918305","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":"Revisiting early Neoproterozoic mafic sills in the North China Craton","authors":"Zhongwu Lan ,&nbsp;Zhensheng Li ,&nbsp;Sandra Kamo ,&nbsp;Peng Peng ,&nbsp;Mingguo Zhai","doi":"10.1016/j.precamres.2025.107788","DOIUrl":"10.1016/j.precamres.2025.107788","url":null,"abstract":"<div><div>Neoproterozoic Large Igneous Provinces (LIPs) continue to receive worldwide attention due to their genetic links with supercontinent dispersal and use in paleocontinental reconstructions, formation of ore deposits, climate shifts, and biological extinctions. However, their utility is hampered by a lack of high precision geochronology. Here we present a new U-Pb ID-TIMS baddeleyite age for a Neoproterozoic mafic sill intrusion in the North China Craton (NCC). A mafic intrusion within the Huaibei/Huaihe Group of Xuhuai Basin, previously dated between 915 Ma and 900 Ma (U-Pb zircon/baddeleyite LA-ICP-MS) gives a baddeleyite age of 906.5 ± 1.1 Ma. Given the wide occurrence of 915–900 Ma mafic intrusions dated previously, this new age potentially suggests a widespread ca. 907 Ma mafic intrusive event across NCC. Furthermore, this baddeleyite age constrained the Huaibei/Huaihe Group to have deposited in an age span of 1121–907 Ma. Apatite grains from the mafic sills have also been dated by U-Pb LA-ICP-MS, which produced dates that range from 984 ± 64 Ma to 930 ± 57 Ma, with errors similar to previous zircon/baddeleyite U-Pb LA-ICP-MS dates, indicating the feasibility of apatite U-Pb geochronology to constrain the timing of mafic intrusions. REE distribution patterns coupled with the Sr/Y-LREE discrimination plots demonstrate a primary origin for the dated apatite grains. Apatite crystallized from mafic magmas following earlier crystallization of feldspar that incorporated significant amounts of Eu.</div><div>Recalculation of nearly 600 radio-isotopic data points on Neoproterozoic mafic intrusions in the NCC yield three age peaks at ca. 940 Ma, ca. 915 Ma and ca. 885 Ma, respectively. The major age peak at ca. 915 Ma is broadly consistent with our U-Pb ID-TIMS baddeleyite age that is suggestive of the main episode of mafic intrusion. Further high precision U-Pb ID-TIMS geochronology is necessary to precisely constrain the timing of the ca. 940 Ma and ca. 885 Ma mafic intrusions.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"423 ","pages":"Article 107788"},"PeriodicalIF":3.2,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918324","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 southwesternmost piece of the Grenville Orogen in Laurentia – New U-Pb and Sm-Nd ages, and P-T estimates from the Sierra del Cuervo, Chihuahua, Mexico","authors":"Bodo Weber ,&nbsp;C. Nayeli Chacón-Olivas ,&nbsp;M. Daniela Tazzo-Rangel ,&nbsp;Miguel Franco-Rubio ,&nbsp;Reneé González-Guzmán ,&nbsp;Felix E.D. Kaufmann ,&nbsp;Dirk Frei","doi":"10.1016/j.precamres.2025.107793","DOIUrl":"10.1016/j.precamres.2025.107793","url":null,"abstract":"<div><div>This paper elucidates the origin and tectonic setting of Mesoproterozoic metaigneous rocks of the Sierra de Cuervo, Chihuahua, Mexico, providing new evidence for the southwestern extension of the Grenville Orogeny in North America. Several geochronological approaches were used, including U-Pb zircon dating by LA-ICP-MS and the Sm-Nd isochron technique, using ID-TIMS. Igneous zircon domains reveal crystallization ages for felsic igneous protoliths ranging from ∼ 1.38 Ga to ∼ 1.33 Ga, with ∼ 1.42 b.yr. old inherited zircon. Whole-rock Sm-Nd isotopic data define an isochron at 1.52 ± 0.03 Ga, suggesting crustal growth during the early Mesoproterozoic. The timing of metamorphism is constrained by Sm-Nd leached garnet-whole-rock isochrons and by U-Pb zircon dates between ∼ 1.06 and ∼ 1.05 Ga. Metamorphic pressure and temperature conditions were estimated from a metamafic rock sample at 6.4 ± 1 kbar and 520 ± 20 °C using conventional geothermobarometry and pseudosection modeling. The results contextualize the Precambrian rocks of the Sierra del Cuervo with metamorphic rocks of the West Texas Uplift thrust over the Laurentian margin. We propose that this thrust represents a remnant of the unexposed Grenville Front and that the Chihuahua and West Texas metamorphic basement is characterized by contemporaneous magmatism and reworked from the Granite-Rhyolite Province of the North American midcontinent during the Grenville Orogeny, comparable to the low-medium pressure allochthonous Ottawan metamorphic belt of the Grenville Province in Canada.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"423 ","pages":"Article 107793"},"PeriodicalIF":3.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912368","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 lithosphere effective elastic thickness with its anisotropy of the North China Craton","authors":"Wen Shi ,&nbsp;Shi Chen ,&nbsp;Yongbo Li ,&nbsp;Yuhang Pan ,&nbsp;Lulu Jia ,&nbsp;Honglei Li ,&nbsp;Huili Guo","doi":"10.1016/j.precamres.2025.107798","DOIUrl":"10.1016/j.precamres.2025.107798","url":null,"abstract":"<div><div>The North China Craton (NCC) is one of the oldest cratons in the world. It is important to understand the mechanism of NCC destruction. The lithosphere effective elastic thickness (<span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span>) with its anisotropy can provide new insights into those mechanisms, as the spatial distribution patterns of <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span> and its anisotropy serve as distinctive indicators of past tectonic processes that are difficult to characterize through conventional approaches. The <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span> and load ratio (<span><math><mrow><mi>F</mi></mrow></math></span>) around the NCC region are estimated using a joint inversion method that integrated both admittance and coherence techniques. The <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span> anisotropy is estimated using fan wavelet coherence method. The derived <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span> and <span><math><mrow><mi>F</mi></mrow></math></span> are used to compute flexural isostatic anomalies (FIA) using the theoretical Bouguer admittance method. We find the <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span>, <span><math><mrow><mi>F</mi></mrow></math></span>, <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span> anisotropy, and FIA vary a lot from east to west in the NCC area. The Ordos Basin in the western North China Craton (WNCC) has high <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span>, low <span><math><mrow><mi>F</mi></mrow></math></span>, and weak <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span> anisotropy, suggesting that the lithosphere of Ordos Basin have high strength and in a state of stable. The Trans-North China Orogen (TNCO) is located in transition zone of <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span>, <span><math><mrow><mi>F</mi></mrow></math></span>, <span><math><mrow><msub><mi>T</mi><mi>e</mi></msub></mrow></math></span> anisotropy, and FIA, indicating that the TNCO could be the front of collision between Eurasia Plate and western Pacific Plate. The eastern North China Craton (ENCC) lithosphere has been largely modified by the deep tectonic activities due to the subduction of western Pacific Plate.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"423 ","pages":"Article 107798"},"PeriodicalIF":3.2,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899368","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":"Neoproterozoic accretionary tectonics of the northern Yangtze Block: Constrains from the geochemistry and geochronology of the volcanic-sedimentary succession","authors":"Shuai He ,&nbsp;Yunpeng Dong ,&nbsp;Feifei Zhang ,&nbsp;Shengsi Sun ,&nbsp;Bo Hui ,&nbsp;Weidong He","doi":"10.1016/j.precamres.2025.107799","DOIUrl":"10.1016/j.precamres.2025.107799","url":null,"abstract":"<div><div>The unclear tectonic evolution of the northern margin of the Yangtze Block during the middle Neoproterozoic impedes our comprehensive understanding of the breakup of the supercontinent Rodinia. The Suixian volcanic-sedimentary group in the South Qinling Belt is crucial for elucidating this issue. This study presents a comprehensive investigation of volcanic rocks within the Suixian Group, utilizing zircon U-Pb geochronology and Hf isotope analysis, whole-rock major and trace element analysis, as well as Sr-Nd isotopic analysis. The geochemical characteristics indicate that the mafic volcanic rocks exhibit three distinct types. The first type resembles island arc basalts, enriched in large ion lithophile elements and depleted in high field strength elements, with positive ε_Nd(t) values, suggesting derivation from mantle metasomatized by subduction-related fluids. The second type displays high Nb values and geochemical characteristics akin to Nb-enriched basalts, possibly linked to slab window tectonics. The third type possesses an E-MORB-like trace element composition and positive ε_Nd(t) values, resembling basalts formed during back-arc extension. Felsic volcanic rocks from the Suixian Group yield zircon U-Pb ages of 747 ± 5 Ma, 743 ± 4 Ma, and 742 ± 5 Ma. These felsic rocks belong to the calc-alkaline to high-K calc-alkaline series and are characterized by enrichment in large ion lithophile elements and depletion in high field strength elements. Zircon Hf isotopic analyses reveal that the felsic rocks exhibit heterogeneous ε_Hf(t) values ranging from -9.2 to -1.0, indicating formation by partial melting of the lower crust triggered by mantle-derived magma. Combined with geological features of the Suixian Group and previous detrital zircon U-Pb geochronological studies, we infer that the formation of the Suixian Group can be attributed to a multistage process encompassing the subduction of oceanic slab in the early stage and subsequent back-arc extension, further confirming a sustained subduction-accretion tectonic setting along the northern margin of the Yangtze Block during the middle Neoproterozoic.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107799"},"PeriodicalIF":3.2,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892133","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":"Delineation of polymetamorphism from the middle-low-grade metamorphic complex in the Dengfeng area, southern North China Craton, resolved by multiple mineral petrochronology and phase equilibrium modelling","authors":"Qiang Feng ,&nbsp;Jun-Sheng Lu ,&nbsp;Xu Kong ,&nbsp;Gang Liu ,&nbsp;Yu-Ting Li ,&nbsp;Yi-Yi Zhang ,&nbsp;Zeng-Yin Duan ,&nbsp;Juan-Juan Li","doi":"10.1016/j.precamres.2025.107802","DOIUrl":"10.1016/j.precamres.2025.107802","url":null,"abstract":"<div><div>Polymetamorphic garnet–bearing amphibolites from the Dengfeng Complex (Central Henan, China) exhibit intricate microstructural and mineral-chemical relationships. Two generations of garnet porphyroblastand various mineral age populations have been identified in this middle-low-grade metamorphic complex. Garnet1, which co-exists with titanite in the ‘dark domain’, exhibits a trend of decreasing Mn, constant Mg and notably increasing Ca from its cores to rims, indicating growth zoning associated with prograde metamorphism from ∼590 °C–650 °C and ∼3.8–4.5 kbar to ∼650 °C–680 °C and ∼5.0–5.6 kbar by phase equilibrium modelling. By contrast, garnet2 from the ‘light domain’ displays a decrease in Ca alongside an increase in Mg and low Mn, reflecting clockwise pressure–temperature (P–T) paths with peak P–T conditions reached at ∼630 °C–645 °C and ∼10.9–11.6 kbar. Laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) zircon U–Pb and amphibole ⁴⁰Ar/³⁹Ar dating yielded polymetamorphic events with extensive Neoarchean records of ∼2.49–2.53 Ga and sporadic Palaeoproterozoic records of ∼1.94–1.86 Ga, respectively. By contrast, LA–(HR)–ICP–MS titanite U–Pb data from the ‘dark domain’ only recorded late Neoarchean metamorphic ages ranging from ∼2.44 to ∼2.54 Ga. The early metamorphism from the ‘dark domain’ is characterised by low pressure and high temperature, indicating a high T/P gradient towards ∼1200 °C–1300 °C/Gpa at the Neoarchean. By contrast, the late metamorphism from the ‘light domain’ underwent clockwise metamorphic cycles at an intermediate T/P gradient of ∼540 °C–590 °C/Gpa during the Palaeoproterozoic. The diachronous evolution of these amphibolites indicates that the Dengfeng Complex in the southern North China Craton has undergone low-pressure facies series metamorphism during the late Neoarchean, which was subsequently incorporated into supercontinent Columbia during the late Palaeoproterozoic cold subduction and continent–continent collision along the Trans-North China Orogen.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107802"},"PeriodicalIF":3.2,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892132","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 Ediacaran margin of the proterozoic MARA block and the sedimentary basins of the Clymene Ocean: Insights from U-Pb zircon geochronology in the Puna-Sierras Pampeanas transition, NW Argentina","authors":"C.D. Ramacciotti ,&nbsp;M.A. Larrovere ,&nbsp;C. Casquet ,&nbsp;C.I.Lembo Wuest ,&nbsp;M.Morales Cámera ,&nbsp;P.H. Alasino ,&nbsp;J.A. Murra ,&nbsp;A. Riveros ,&nbsp;M.A.S. Basei ,&nbsp;L. Herazo ,&nbsp;E.G. Baldo","doi":"10.1016/j.precamres.2025.107792","DOIUrl":"10.1016/j.precamres.2025.107792","url":null,"abstract":"<div><div>The basement of the sierras of Fiambalá and Altohuasi, in the Puna-Sierras Pampeanas transition (NW Argentina), consists mainly of early Cambrian metamorphic rocks (Fiambalá Metasedimentary Complex; new name) and granitoids (Loconte Intrusive Complex; new name). The metasedimentary complex consists of: 1) the Tatón Unit (gneisses, metatexites, diatexites and mylonites); and 2) the Laguna Helada Unit (low- to medium-grade fine-grained metaconglomerates with subordinated metapsammites, slates, phyllites, schists, mylonites and marbles). U-Pb zircon geochronology performed in the two units yields similar results suggesting that they were sourced from the same basements and probably belong to a continuous stratigraphic pile prior to metamorphism and ductile shearing. These units show a main group of ages between ca. 0.95 and 1.10 Ga, and a secondary group at ca. 1.15–1.25 Ga, with a minor peak at ca. 1.33 Ga, and few Paleoproterozoic-Neoarchean ages. This, along with zircon metamorphic overgrowths of 526 ± 4 Ma found in the Tatón Unit, and regional correlations, indicate that sedimentation took place in Ediacaran to early Cambrian times, in a mixed carbonate-siliciclastic platform bordering the extinct Clymene Ocean. Comparisons (lithology, Sr-isotopes and detrital zircon data) with similar successions recognized elsewhere in the Sierras Pampeanas, southern Puna, Cordillera Frontal, and Cordillera Oriental suggest that the sediments came from the same source areas and that they were part of a common sedimentary environment, i.e., the Difunta Correa Basin. The main source areas were the Grenville and the Granite-Rhyolite provinces of Laurentia and the MARA block. This basin – now dismembered by Paleozoic deformation – is one of the many basins formed along the margins of the Clymene Ocean lying in NW Argentina, southern Brazil, Paraguay, and Río de la Plata craton. The closure of this ocean, during the early Cambrian Pampean orogeny resulted in the low- to high-grade metamorphism of the Fiambalá Metasedimentary Complex.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107792"},"PeriodicalIF":3.2,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143879071","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":"Late Tonian subduction to collisional tectonics in the southwestern Tarim Craton: Arc volcanism and sedimentary archives of terminal Rodinia amalgamation","authors":"Duwei Qiu ,&nbsp;Fengqi Zhang ,&nbsp;Hongxiang Wu ,&nbsp;Yildirim Dilek ,&nbsp;Caiyun Wang ,&nbsp;Hanlin Chen ,&nbsp;Kongyang Zhu","doi":"10.1016/j.precamres.2025.107795","DOIUrl":"10.1016/j.precamres.2025.107795","url":null,"abstract":"<div><div>The southwestern margin of the Tarim Craton preserves significant geological records related to the assembly and fragmentation of the Rodinia Supercontinent. However, its Neoproterozoic tectonic evolution remains debated, complicating the reconstruction of the Tarim Craton within the Rodinia framework. This study presents a multidisciplinary approach integrating stratigraphic, geochronological, geochemical, and provenance analyses of Tonian successions and tuffaceous interlayers to constrain the timing and mechanisms of contractional events in the southwestern Tarim Craton. The Tonian Silu Group shows a regressive succession from shallow marine to fluvial-deltaic environments, capped by a regional unconformity beneath Cryogenian-Ediacaran strata. Tuffaceous interlayers suggest volcanic eruptions occurred between 802 Ma and 789 Ma, providing age constraints for the Sukuluoke Formation at the top of the Silu Group. These calc-alkaline tuffs exhibit arc-related geochemical signatures, suggesting continental arc magmatism along the southwestern margin of the Tarim Craton. Detrital zircon provenance and sedimentary facies analyses reveal that proximal Tonian magmatic arc clasts contributed significantly to the basins, possibly sharing a common source with the volcanic tuff. These findings, along with regional magmatism, stratigraphic unconformities, and coeval metamorphism, collectively suggest a mid-Neoproterozoic assembly event involving subduction and collision. A plausible tectonic scenario involving subduction, collision, and subsequent rifting is proposed for the Neoproterozoic evolution of the southwestern Tarim Craton. This model serves as a preliminary framework that will require further geological constraints to refine the regional geological history.</div></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"422 ","pages":"Article 107795"},"PeriodicalIF":3.2,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143882287","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}