Precambrian Research最新文献

{"title":"An arc terrane separated from the Yangtze Craton during Rodinia breakup: Insights from Neoproterozoic sedimentary successions of the Erguna Block, Northeast China","authors":"Ke Wang ,&nbsp;Yilong Li ,&nbsp;Wenjiao Xiao ,&nbsp;Haitian Zhang ,&nbsp;Guoqing Wang ,&nbsp;Jianping Zheng ,&nbsp;Xiujuan Bai ,&nbsp;Guang Yang ,&nbsp;Guohui Zhang ,&nbsp;Fraukje M. Brouwer","doi":"10.1016/j.precamres.2024.107497","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107497","url":null,"abstract":"<div><p>The Central Asian Orogenic Belt (CAOB) is one of the largest and most complex accretionary systems and is responsible for considerable Phanerozoic juvenile crustal growth. The Erguna Block is a Precambrian microcontinent located in the eastern part of the CAOB. Controversy has long surrounded the origin and tectonic affinity of the Erguna Block, limiting reconstruction of its position in the supercontinent Rodinia. This study presents a systematic study of the petrology, whole-rock geochemistry and zircon U-Pb-Hf isotopes of metasedimentary rocks from the Ergunahe Formation, the Jiageda Formation and the Xinghuadukou Group, which are the oldest units in the Erguna Block. The samples from the Ergunahe Formation comprise phyllite and schist with detrital zircon ages of 2476–743 Ma, maximum protoliths depositional ages of 817–743 Ma and peaks at 763 Ma, 896 Ma and 1162 Ma, εHf_(t) values of −15.54 to +11.66 and T_DM2 model ages of 3464–978 Ma. The Jiageda Formation samples include metasandstone, metapelite and schist with detrital zircon ages of 2976–766 Ma, maximum protoliths depositional ages of 837–766 Ma and peaks at 776 Ma, 843 Ma, 918 Ma and 984 Ma, εHf_(t) values of −9.46 to +14.68 and T_DM2 model ages of 3207–866 Ma. From the Xinghuadukou Group, schists are studied with detrital zircon ages of 2908–785 Ma, maximum protoliths depositional ages of 839–785 Ma and peaks at 837 Ma and 907 Ma, εHf_(t) values of −14.35 to +12.68 and T_DM2 model ages of 3949–926 Ma. The protoliths of the metasedimentary rocks from the three groups have similar depositional age spans and source rocks. They are mainly siltstones and greywackes and represent a sedimentary sequence in a continental arc-related basin. The source rocks for the protoliths were mainly arc magmatic rocks in the Erguna Block, which were formed in a continental arc as oceanic lithosphere subducted during the assembly and break-up of the Rodinia supercontinent. Combined with existing data, the age spectrum and multidimensional scaling (MDS) analysis of detrital zircon indicate the Erguna Block originated from a continental arc at the margin of the Yangtze Craton. Long-term subduction at <em>ca.</em> 963–737 Ma accompanied by back-arc extension during <em>ca.</em> 904–737 Ma led to rifting of the Erguna Block off the Yangtze Craton. Neoproterozoic sedimentary rock assemblages from the Erguna Block were deposited in a large-scale long-term trench-arc-basin system that formed in front of the Yangtze Craton, along the northwest margin of Rodinia.</p></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107497"},"PeriodicalIF":3.2,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539204","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":"Comment on ‘New evidence for the Baltican cratonic affinity and Tonian to Ediacaran tectonic evolution of West Avalonia in the Avalon Peninsula, Newfoundland, Canada’","authors":"Ed Landing,&nbsp;Gerd Geyer","doi":"10.1016/j.precamres.2024.107489","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107489","url":null,"abstract":"","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107489"},"PeriodicalIF":3.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539993","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":"Reply to comment on: Carbonaceous matter in ∼3.5 Ga black bedded barite from the Dresser Formation (Pilbara Craton, Western Australia) – Insights into organic cycling on the juvenile earth","authors":"L. Weimann ,&nbsp;M. Reinhardt ,&nbsp;J.-P. Duda ,&nbsp;H. Mißbach-Karmrodt ,&nbsp;H. Drake ,&nbsp;J. Schönig ,&nbsp;J. Holburg ,&nbsp;L.B. Andreas ,&nbsp;J. Reitner ,&nbsp;M.J. Whitehouse ,&nbsp;V. Thiel","doi":"10.1016/j.precamres.2024.107494","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107494","url":null,"abstract":"","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107494"},"PeriodicalIF":3.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484376","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":"Comment on Rocha et al. (2024): “The passive margin of the southern São Francisco paleocontinent, metamorphic record and implications for the assembly of West Gondwana: Evidence from the Lima Duarte Nappe, Ribeira Orogen (SE Brazil)”, Precambrian Research 404, 107338","authors":"Rudolph A.J. Trouw,&nbsp;André Ribeiro","doi":"10.1016/j.precamres.2024.107458","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107458","url":null,"abstract":"","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107458"},"PeriodicalIF":3.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141540000","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 2.03–2.02 Ga arc–back-arc mafic magmatism from the Zhongxiang Complex, northern Yangtze Block: Implications for Columbia supercontinent assembly","authors":"Hao Liu ,&nbsp;Qi Deng ,&nbsp;Jian Wang ,&nbsp;Zhengjiang Wang ,&nbsp;Xiaozhuang Cui ,&nbsp;Guoqing Xiong ,&nbsp;Kuobu Ning ,&nbsp;Guangming Ren","doi":"10.1016/j.precamres.2024.107485","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107485","url":null,"abstract":"<div><p>To better understand Paleoproterozoic tectonic processes in the Yangtze Block during the assembly of the Columbia supercontinent, an integrated geochronological and geochemical study of amphibolite facies mafic rocks exposed in the Zhongxiang Complex in the northern Yangtze Block is presented. Based on trace element and rare earth element (REE) characteristics, these mafic rocks can be divided into two coeval groups. The MORB-like mafic rocks show flat REE patterns and are enriched in large-ion lithophile elements (e.g. Rb, Ba, K, Sr). Their zircon ɛ_Hf(<em>t</em>) values range from + 3.43 to + 4.90. The other mafic rocks are arc-like and have elevated REE contents and display relatively light REE enriched patterns, as well as depletion in high field strength elements (e.g. Nb, Ta, Ti). The zircon ɛ_Hf(<em>t</em>) values of the latter group range from + 0.17 to + 2.68. Zircon U-Pb dating yielded a weighted mean ²⁰⁷Pb/²⁰⁶Pb age of 2029 ± 15 Ma for the MORB-like mafic rocks, and 2023 ± 14 Ma for the arc-like mafic rocks, respectively. The elemental and isotopic characteristics indicate that the MORB-like mafic rocks may be derived from a depleted asthenospheric mantle source, whereas its counterpart with arc-like signatures originated from a lithospheric mantle source. The low (La/Yb)_CN (1.10–2.84) and Sm/Yb (0.99–1.29) ratios indicate that the mafic rocks are formed by partial melting of spinel lherzolite mantle. Combined with other geological observations, these mafic rocks are inferred to constitute part of a mid-Paleoproterozoic continental arc–back-arc basin system. The 2.03–2.02 Ga mafic rocks from the northern Yangtze Block indicate that the continental margin experienced subduction in response to assembly of the Columbia supercontinent.</p></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107485"},"PeriodicalIF":3.2,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484375","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 deformed alkaline Balda granite (Northern Cameroon): A witness of back-arc basin in the northern part of Central African Orogenic Belt","authors":"Aboubakar Bello ,&nbsp;Daouda Dawaï ,&nbsp;Paul Yves Jean Antonio ,&nbsp;Oscar Laurent ,&nbsp;Carmen Irene Martinez Dopico ,&nbsp;Rigobert Tchameni ,&nbsp;Olivier Vanderhaeghe","doi":"10.1016/j.precamres.2024.107490","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107490","url":null,"abstract":"<div><p>Located on the border between the NW Cameroon and Mayo-Kebbi domains in northern Cameroon, the Balda pluton is a deformed alkaline granite. Due to its unique location and geological features, it holds crucial information for understanding the evolution of the Central African Orogenic Belt (CAOB), which remains poorly understood. This multidisciplinary study combines field data, microscopic observations, Anisotropy of Magnetic Susceptibility (AMS), and U-Pb zircon dating to constrain the geodynamic evolution of the CAOB.</p><p>The Balda pluton is a NNE-SSW elongated pluton consists mainly of aegirine-riebeckite granite and leucogranite. It displays diverse magnetic susceptibility values (Km) spanning from 0.19 x 10^-3 to 21.98 x 10^-3. Notably, 93 % of the Km values exceed 5 × 10^-4SI, indicating a prevalence of mixed paramagnetic and ferromagnetic mineralogy (such as magnetite-rich). This observation is supported by microscopic examinations and K-T curves. An analysis of AMS unveils high P% values (2.8 to 58.7 %, with a mean of 15 %) and prevalent oblate magnetic fabrics (68 %). The magnetic foliation generally aligns with the field foliation and has steep dips ranging from NNE to NE or from SSW to SW and magnetic lineations exhibit shallow plunges (&lt;35°) from SSW to SW. Microscopic analysis reveals high-temperature, solid-state deformation microstructures, indicating post-emplacement deformation processes and the presence of kinematic markers consistent with sinistral shear. Zircon grain analysis reveals two distinct types: “bright” and “dark.” These types differ in both their appearance under cathodoluminescence and their chemical composition. Bright zircons yield a U-Pb age of 732.7 ± 7.5 Ma, interpreted as the pluton emplacement age. Dark zircons are younger (ca. 680 Ma), suggesting a later tectono-metamorphic or alteration event.</p><p>The integration of these results in a larger geodynamic context suggests that the Balda pluton formed within a <em>syn</em>-orogenic extensional back-arc basin. This emplacement was followed by significant post-emplacement deformation characterized by sinistral simple shear-dominated transpression likely related to the continental collision (ca. 680 Ma) of the NW Cameroon and Mayo-Kébbi domains.</p></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107490"},"PeriodicalIF":3.2,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484374","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":"Episodic hydrothermal supply and microbial anaerobic Fe(II) oxidation in early Archean ocean: Insights from precursor mineral compositions of the 3.46 Ga Marble Bar Chert, Pilbara Craton, Western Australia","authors":"Si Sun ,&nbsp;Yiliang Li","doi":"10.1016/j.precamres.2024.107484","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107484","url":null,"abstract":"<div><p>The 3.46 Ga Marble Bar Chert (MBC) from the Pilbara Craton in Western Australia is known as the oldest chert on Earth. The origin of its Fe minerals was investigated to decipher the geochemistry and redox conditions of the early Archean ocean, as well as to explore the possible microbial contribution to the earliest sedimentary processes on Earth. However, the composition of the precursor minerals in the MBC remains poorly understood, giving rise to controversies on its genesis. Here we performed high-resolution petrographic, laser Raman, Mössbauer, X-ray diffraction, and Mn K-edge X-ray absorption near edge structure spectroscopic studies on two typical types of finely laminated MBC, grey-black chert and red chert. The grey-black chert contains considerable amounts of siderite, carbonaceous materials, and minor phyllosilicates and hematite. By contrast, the red chert contains high hematite and silicates, minor siderite and rare carbonaceous materials. Microcrystals in the cores of chert polyhedral are among the earliest mineral phases without signs of alterations, recrystallisation, erosion or replacement histories. Ferrihydrite, greenalite, siderite, and green rust are possible precursors of Fe-bearing minerals in the MBC. Their respective proportion in each lamina was regulated by pH, Fe(II)-oxidation rate, DIC, and Fe(II) content in the seawater. Approximately half Fe in the MBC primary minerals existed as Fe(III), indicating the existence of indigenous Fe(II)-oxidation in the Paleoarchean seawater. The element Mn in the MBC is primarily Mn(II) coordinated with O, suggesting a reduced depositional environment and hence implying the involvement of anaerobic microbial Fe(II)-oxidation in the formation of the MBC. Collectively, the grey-black laminae with abundant carbonaceous materials reflect limited Fe(II)-oxidation and increased dissolved inorganic carbon content likely due to enhanced hydrothermal CO₂ supply, while the red laminae with considerable hematite represent substantial Fe(III)-supply due to rapid indigenous anaerobic Fe(II)-oxidation.</p></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107484"},"PeriodicalIF":3.2,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484373","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 and Sr-Nd-Pb-Hf-O isotopes of Neoproterozoic orthogneisses in the Jiamusi Block, NE China: Implications for tectonic origin and secular crustal evolution","authors":"Xin Ding ,&nbsp;Hao Yang ,&nbsp;Zheng Ji ,&nbsp;Yan-Long Zhang ,&nbsp;Hao-Ran Wu ,&nbsp;Yu Dong ,&nbsp;Guan-Ying Yu ,&nbsp;Wen-Chun Ge","doi":"10.1016/j.precamres.2024.107486","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107486","url":null,"abstract":"<div><p>There is a considerable debate as to when and how the continental crust has evolved to its present state. Existing studies of crustal evolution have focused on large cratons, whereas microcontinents within accretionary orogenic belts have been conspicuously neglected. The controversial definition of tectonic origins and lack of Precambrian basement rocks of microcontinents, lead to an equivocal issue of their secular crustal evolution processes. Here we present zircon U-Pb ages and Hf-O isotopes, as well as whole-rock elemental and Sr-Nd-Pb-Hf isotopic data for the newly discovered Neoproterozoic orthogneisses from the Jiamusi Block of NE China in the easternmost Central Asian Orogenic Belt (CAOB). LA-ICP-MS U-Pb dating of zircons from the orthogneisses recorded two episodes of magmatism at 896–886 Ma and 752–726 Ma. Combined with zircon Hf-O isotopes and REE patterns, the peak of the late Pan-African metamorphism is proved to occur at 566–565 Ma, demonstrating the linkage between the Jiamusi Block and the Kuunga-Pinjarra interior orogen of East Gondwana. In conjunction with compiled zircon U-Pb-Hf isotopic data of Neoproterozoic-Mesozoic granitoids, a new crustal evolution model has been established for the Jiamusi Block, which defines a continuous rather than an episodic crustal growth pattern during the Neoarchean to Neoproterozoic, as well as four stages of crustal reworking at 940–880 Ma, 780–660 Ma, 560–460 Ma, and 340–240 Ma. The enhanced and reduced rates of crustal growth during the progressive period are related to the assembly-breakup and collision phases of supercontinent cycles, respectively. Our study along with previous researches on eastern CAOB not only highlights that the Phanerozoic accretionary orogen underwent diverse forms of crustal growth with most of the continental crust formed during the Precambrian, but also provides an example to show the heterogeneity of the lower continent and the complexity of global secular crustal evolution.</p></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107486"},"PeriodicalIF":3.2,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484372","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":"Studies on the 2.2 Ga monzogranite and its wall rocks in western part of North Qinling Orogen: Constraints on early Precambrian tectonic attributes and evolution of the southwestern margin of Ordos Block","authors":"Yuan Tang,&nbsp;Danling Chen,&nbsp;Yunfei Ren,&nbsp;Bowen Bai,&nbsp;Haijie Wang","doi":"10.1016/j.precamres.2024.107488","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107488","url":null,"abstract":"<div><p>Precambrian continent remnants in Phanerozoic orogenic belts contain vital information about not only the Precambrian evolution history of continent remnants but also the relationship between orogenic belts and adjacent blocks. This paper presents an integrated study of petrology, geochemistry and accessory mineral chronology on a monzogranite, its wall rocks biotite-quartz schist and an amphibolite interlayer in the schist in the Kuanping Group, from the western part of the North Qinling Orogen (NQO), adjacent to the southwestern margin of the Ordos Block (OB). The results reveal that the crystallization age of the monzogranite is 2200 ± 12 Ma and the protolith of the biotite-quartz schist deposited during 526–447 Ma, and they experienced similar multistage metamorphism during 450–400 Ma. The 2.2 Ga formation age of the monzogranite is significantly older than the protolith deposition age of the biotite-quartz schist, and there is almost no ca. 2.2 Ga detrital zircon age in the schist, indicating that the monzogranite is neither an intrusive body in the Kuanping Group, nor its provenance. Considering the ca. 2.2 Ga magmatism is widely distributed in North China Craton but never found in the NQO, and the monzogranite and host schist recorded similar metamorphic ages, we proposed that the monzogranite initially formed at the southwestern margin of the North China Craton and involved into the NQO during the closure of the Kuanping sedimentary basin at early Paleozoic. Combined with existing studies, three Paleoproterozoic magmatic events of ca. 2.5 Ga, 2.2–2.0 Ga and 1.8–1.75 Ga, and one ca. 1.9–1.85 Ga metamorphic event occurred at the southwestern margin of OB. These tectono-thermal events as well as their geological setting are very similar to the basement rocks of the central-southern part of the OB. Therefore, the early Precambrian rocks at the southwestern margin of the OB should belong to the basement of the central-southern part of OB, and the late tectonic events placed them at their present position.</p></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107488"},"PeriodicalIF":3.2,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484371","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":"Organic geochemistry, sedimentology and palaeontology of the Khatyspyt Formation, Arctic Siberia: Towards an integrated view of Ediacaran biofacies","authors":"Dmitry Melnik ,&nbsp;Tatyana Parfenova ,&nbsp;Vladimir Rogov ,&nbsp;Jan-Peter Duda ,&nbsp;Dmitriy Grazhdankin","doi":"10.1016/j.precamres.2024.107460","DOIUrl":"https://doi.org/10.1016/j.precamres.2024.107460","url":null,"abstract":"<div><p>The terminal Ediacaran Khatyspyt Lagerstätte (ca. 550–544 Ma) of Arctic Siberia has been a prime target for geobiological research. Previous evidence suggested that Ediacaran macroscopic soft-bodied organisms could be highly sensitive to sedimentary processes and various environmental factors such as water column stratification and seawater redox-conditions. By integrating organic geochemistry, sedimentology, and palaeontology of the Khatyspyt Formation, we identified three biofacies. The most proximal <em>Longifuniculum</em> biofacies consists of outer- to mid-ramp debris flow deposits and is characterised by a high taxonomic diversity and biomarker proxies pointing to a non-stratified non-euxinic water column. The most distal <em>Aspidella</em> biofacies comprises outer-ramp thin-bedded calcareous turbidites and is also marked by a high taxonomic diversity, although the associated biomarker proxies provide evidence for a stratified euxinic environment. Transient between those is the <em>Nenoxites</em> biofacies, consisting of outer- to mid-ramp debris flow deposits and characterised by a low taxonomic diversity, with biomarker proxies indicating redox instability. This systematic pattern suggests that the distribution of Ediacaran organisms was influenced by a heterogenous redox landscape. More specifically, the highest diversity of benthic soft-bodied organisms, including the iconic <em>Charnia masoni</em>, appears in stratified euxinic environments, while the highest diversity of macroalgae is found in non-stratified settings. The occurrence of a complex Ediacaran community in a stratified euxinic environment suggests that anoxia might have driven ecological differentiation of organisms, and that heterogeneous and dynamic redox landscapes were far more significant in early animal evolution than hitherto appreciated.</p></div>","PeriodicalId":49674,"journal":{"name":"Precambrian Research","volume":"410 ","pages":"Article 107460"},"PeriodicalIF":3.2,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141484377","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}