Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Glaciovolcanic processes between the Campbell Glacier and Mt. Melbourne Volcano, Antarctica: ICE and FIRE","authors":"Hyun Hee Rhee ,&nbsp;Min Kyung Lee ,&nbsp;Yeong Bae Seong ,&nbsp;Sunghan Kim ,&nbsp;Jae Il Lee ,&nbsp;Kyu-Cheul Yoo ,&nbsp;Byung Yong Yu","doi":"10.1016/j.palaeo.2024.112611","DOIUrl":"10.1016/j.palaeo.2024.112611","url":null,"abstract":"<div><div>This study investigates the glacial dynamics of the Campbell Glacier in Terra Nova Bay (TNB), Antarctica, with a focus on its unique lowering patterns during the late Quaternary. Using cosmogenic nuclides (¹⁰Be) surface exposure dating, we provide significant chronological constraints on Antarctic terrestrial glacier changes. In addition to the previous data on Marine Isotope Stage (MIS) 5 simple exposure ages of Campbell Glacier moraines, we further analyzed the palaeo-subglaciated bedrock, which yields exposure ages during MIS 3 and 2 (49.8–28.5 ka). Our analysis empowers that continuous glacial lowering occurred throughout the late Quaternary, even during the Last Glacial Period (MIS 4–2), and that the Local Last Glacial Maximum (LLGM) occurred at 150–90 masl during MIS 4 rather than MIS 2. This new and recalculated dataset for the Campbell Glacier is unique compared to other outlet glaciers flowing into the Terra Nova Bay, highlighting the significant influence of Mt. Melbourne's volcanic activity via glaciovolcanic processes during the late Quaternary, beyond general climatic and oceanic factors. Further studies of palaeo-glaciovolcanic interactions on the East Antarctic Ice Sheet (EAIS) promise to provide more robust insights for refining models predicting future accelerated glacial melt and sea level rise, particularly considering the numerous volcanoes beneath the West Antarctic Ice Sheet (WAIS).</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"657 ","pages":"Article 112611"},"PeriodicalIF":2.6,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720641","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":"Exploring the deep water mass turnovers in the Eastern Indian Ocean since the late Oligocene: Significance of ocean gateways and paleoclimate","authors":"Himanshu Bali ,&nbsp;Anil K. Gupta ,&nbsp;Sudheer Joseph ,&nbsp;Arun Kaushik","doi":"10.1016/j.palaeo.2024.112607","DOIUrl":"10.1016/j.palaeo.2024.112607","url":null,"abstract":"<div><div>Tectonically driven adjustments within ocean gateways and their impacts on deep water production, thermohaline circulation, and nutrient distribution are well constrained. With no deep water formation in the modern northern Indian Ocean, this study aims to reconstruct the possible source and pathways of deep circulation since the late Oligocene, altering the water mass properties at study sites in the eastern Indian Ocean. Our benthic foraminifera results suggest that tectonic gateways influenced the deep water masses in the eastern Indian Ocean. Significant changes in deep water masses at the studied sites commenced with a gradual reduction in corrosive deep water in the eastern equatorial Indian Ocean (EIO) due to the inflow of relatively warmer and less corrosive Tethyan Overflow Water (TOW) through the Tethyan Gateway in the late Oligocene (∼24 Ma). The EIO gradually became less corrosive from the late Oligocene to the middle Miocene (∼24 to 14 Ma). This turnover reflects the intrusion of southward-flowing TOW and a reduction in the Antarctic Bottom Water (AABW) between ∼24 and ∼ 14.5 Ma in the Indian Ocean. Hereafter, a significant switch in deep water mass was established, contemporaneous with the expansion of Antarctic ice sheets that led to the enhanced production of cold and corrosive AABW that replaced the warm and less corrosive TOW at ∼14 Ma. Furthermore, between ∼12 and 8 Ma the closure of the Tethys Seaway caused a significant hydrological reorganization, replacing the TOW with the Pacific Deep Water (PDW) and North Component Water (NCW). At ∼8 Ma, the contribution of the PDW diminished and AABW flow increased again after a reduction between 12 and 8 Ma, leading to a gradual increase in corrosive deep water. Since 8 Ma, a circulation pattern resembling the modern framework was established with the intrusion of the North Atlantic Deep Water into the CDW, and this pattern was developed by ∼5.7 Ma. Furthermore, the final closure of the Central American Seaway increased the formation of the NADW and its intrusion into the CDW after ∼3.2 Ma.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"657 ","pages":"Article 112607"},"PeriodicalIF":2.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720441","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 Triassic sedimentary environments and detrital zircon provenance analysis in the Amdo area of the Tibetan Plateau: Implications for the evolution of the Meso-Tethys Ocean","authors":"Shiyao Gao ,&nbsp;Zhongjie Xu ,&nbsp;Chaoming Xie ,&nbsp;Zainaibai Ma ,&nbsp;Peizhao Deng ,&nbsp;Haoxuan Liu","doi":"10.1016/j.palaeo.2024.112601","DOIUrl":"10.1016/j.palaeo.2024.112601","url":null,"abstract":"<div><div>Aspects of the early Mesozoic evolution of the Meso-Tethys Ocean remain uncertain, and detrital zircon provenance analyses may be useful for constraining the development of this region. In this paper, we describe Late Triassic sedimentary facies, petrography, geochemistry, and detrital zircon U<img>Pb geochronology for the Tumengela Formation (South Qiangtang Basin) and the Quehala Formation (Amdo back-arc basin) in the Tibetan Plateau. In Late Triassic times, the South Qiangtang Basin was characterized by marine deltaic environments adjacent to an evaporative platform, whereas the Amdo back-arc basin was characterized by a shallow marine shelf fringed by tidally-influenced deltas; in both basins, marine palaeoenvironments first deepened and then shallowed. By analyzing the characteristics of detrital zircon U<img>Pb age spectra for each microcontinent on the northern margin of Gondwana, and combining them with previously published data, we infer that the North and South Qiangtang Terranes amalgamated in Late Triassic times, and were separated from the Lhasa Terrane by the wide Meso-Tethys Ocean. During the Late Triassic, the Meso-Tethys Ocean began to be subducted, and the southern edge of the South Qiangtang Terrane developed as an active continental margin. The Quehala Formation accumulated in the back-arc basin of the Amdo microcontinent during subduction of the Meso-Tethys Ocean, and the uppermost part of Member 2 of the Quehala Formation is dated as no older than Early Jurassic.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"657 ","pages":"Article 112601"},"PeriodicalIF":2.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720442","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":"Skolithos piperock from the Lower Devonian storm beds","authors":"Daniel Sedorko ,&nbsp;Dirk Knaust ,&nbsp;Marcelo Nery Junior ,&nbsp;Gabriel Eduardo Barea de Barros ,&nbsp;Victor Ribeiro ,&nbsp;Felipe Nascimento Sousa ,&nbsp;Renato Pirani Ghilardi ,&nbsp;Leonardo Borghi","doi":"10.1016/j.palaeo.2024.112604","DOIUrl":"10.1016/j.palaeo.2024.112604","url":null,"abstract":"<div><div><em>Skolithos</em> piperock is prevalent in Cambrian shallow marine deposits but diminishes throughout the Paleozoic. This study reports an interval with <em>Skolithos</em> piperock from the upper Furnas Formation (Lower Devonian), offering insights into the paleoenvironmental interpretation of nearshore sandstones. The studied section comprises eight sedimentary facies, transitioning from sandstone-dominated intervals indicative of nearshore environments to siltstone and mudstone facies representing lower energy transitional offshore conditions. Trace fossils are grouped into six ichnocoenoses, reflecting varying depositional settings from proximal to distal in the coastal zone. Notable shifts in ichnocoenosis composition, particularly the transition from <em>Skolithos</em> piperock to the <em>Asterosoma</em> ichnocoenosis, mark stratigraphic boundaries and highlight a transgressive trend between the Furnas and Ponta Grossa formations. The identification of <em>Skolithos</em> piperock provides evidence of storm-generated deposits and reworking activities, which can be applied to basin-scale correlations. This occurrence of a <em>Skolithos</em> piperock is interpreted as the result of several erosive processes triggered by storms, generating a time-averaged ichnoassemblage.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"656 ","pages":"Article 112604"},"PeriodicalIF":2.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660910","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":"Sedimentary provenance and paleogeographic environment of a Mississippian coal-bearing unit in South China: Constraints from detrital zircon U-Pb ages and sedimentologic and geochemical evidence","authors":"Yuliang Mu,&nbsp;Rongsong Tian,&nbsp;Yong Fu,&nbsp;Li Yang,&nbsp;Jiang Hu","doi":"10.1016/j.palaeo.2024.112605","DOIUrl":"10.1016/j.palaeo.2024.112605","url":null,"abstract":"<div><div>The Mississippian Xiangbai Formation in South China is one of the oldest coal-bearing sedimentary units in China. However, the sedimentary provenance, paleogeography, and coal formation patterns of the coal-bearing strata are not well constrained. We address this key issue by using a combination of detrital zircon U-Pb data, geochemical analyses of mudstone and shale, drilling data, and geologic field observations. With the exception of the early Paleozoic orogenic events (ca. 440–420 Ma) in the eastern part of the study area, the samples from the Xiangbai Formation exhibit similar detrital zircon U-Pb age distribution with major age peaks at ca. 980–960 Ma and several subordinate age peaks at ca. 800–780 and 600–500 Ma. These detrital zircon grains mainly originated from recycled sedimentary units. Field and drilling data reveal that the Xiangbai Formation was formed in a tidal flat environment with water depth gradually increasing from the bottom to the top, indicating an overall trend of transgression. The Mississippian Xiangbai Formation was deposited in an interglacial period. The Lower Xiangbai Formation was deposited in a relatively cold paleoclimate, gradually transitioning upwards to a warm and humid climate, creating favorable conditions for coal formation. The alternation of warming and cooling climates triggered high-frequency eustatic fluctuations, which led to multiple sedimentary cycles and resulted in thin, unstable coal seams within the Xiangbai Formation. Mississippian sedimentary paleogeography, palaeoclimate, and sedimentary provenance together dominate the coal-bearing clastic sediments in southwestern South China.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"656 ","pages":"Article 112605"},"PeriodicalIF":2.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660909","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":"Indian summer monsoon history during the last glacial cycle revealed by a loess sequence from the Tibetan Plateau","authors":"Pushuang Li ,&nbsp;Shengli Yang ,&nbsp;Yuanlong Luo ,&nbsp;Li Liu ,&nbsp;Yixiao Zhang ,&nbsp;Weiming Liu ,&nbsp;Jingzhao Zhang ,&nbsp;Xuechao Xu ,&nbsp;Chen Wen ,&nbsp;Qiong Li","doi":"10.1016/j.palaeo.2024.112593","DOIUrl":"10.1016/j.palaeo.2024.112593","url":null,"abstract":"<div><div>The Indian Summer Monsoon (ISM) has a profound influence on the environment and people of East Asia. However, despite its importance, the variability and dynamic mechanisms of the ISM remain inadequately understood. This study investigates the evolution of the ISM since the Last Interglacial by analyzing the well-preserved Cuoweng (CW) loess–paleosol sequence in the southeastern Tibetan Plateau. A robust chronological framework is established using quartz optically stimulated luminescence (OSL) dating and K-feldspar post-infrared infrared stimulated luminescence (pIRIR) dating. The history of the ISM over the past ∼135 ka is reconstructed based on multiple environmental proxies. The results indicate that the ISM experienced significant glacial–interglacial fluctuations during the last glacial cycle, exhibiting a strengthened monsoon during warm periods and a weakened one during cold periods. Additionally, suborbital-scale cyclic variations in the ISM during the marine isotope stage (MIS) 5 are revealed, with enhanced monsoon conditions during MIS 5a, 5c, and 5e and weakened conditions during MIS 5b and 5d. These findings suggest that the ISM variations are primarily influenced by a combination of high- and low-latitude forcing. This study provides new insights into the complex responses of the ISM to climate change, enhancing our understanding of its potential future changes.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"657 ","pages":"Article 112593"},"PeriodicalIF":2.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720644","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":"Quaternary transgression process controlled by tectonic subsidence over the last 1.35 Ma: New insights from the eastern Bohai Sea","authors":"Wei Xiong ,&nbsp;Long Huang ,&nbsp;Yong Zhang ,&nbsp;Zhonglei Wang ,&nbsp;Nai Shuang Bi ,&nbsp;Jun Pan ,&nbsp;Jun Sun ,&nbsp;Lelong He ,&nbsp;Feifei Wang ,&nbsp;Xi Mei","doi":"10.1016/j.palaeo.2024.112602","DOIUrl":"10.1016/j.palaeo.2024.112602","url":null,"abstract":"<div><div>The Quaternary sedimentary history of the Yellow Sea and Bohai Sea offers significant insights into global sea-level changes. This history is intricately linked to tectonic subsidence. However, the process of the Quaternary transgressions of these areas remains controversial due to the lack of cores with comprehensive sedimentary sequences and reliable chronological frameworks in representative sites. This study evaluated the grain size, benthic foraminifera assemblages, quartz optically stimulated luminescence (OSL) dates, and magnetostratigraphy of Core CSH05 (102.4 m) from the eastern boundary of the Bohai Sea. By comparing these results with previous research, new insights were gained into sea-level changes and tectonic events in the Bohai Sea. The paleomagnetic analysis revealed the existence of Brunhes and Matuyama chrons in the core, including the Jaramillo and Cobb Mountain subchrons and Blake excursion. The boundary between the Brunhes and Matuyama chrons was determined at 57.2 m in the core, aligning with adjacent cores. The basal age of the core is estimated to be ∼1.35 Ma. Thirteen sedimentary units (U1-U13), consisting of seven neritic deposits and six terrestrial/littoral deposit layers, were identified in the core through sedimentology and environmental proxies (grain size and benthic foraminifera), indicating alternating transgression-regression cycles. OSL samples suggest that the neritic deposits layer (16.2–20.6 m) probably originated during the early Marine Isotope Stage 3 (MIS3), exhibiting a weaker transgression than MIS5 and MIS1. The initial transgression (U13) dates back to no later than 1.35 Ma, representing the earliest documentation in the Bohai Sea. U11 shows a transgression to 1 Ma, aligning with results from adjacent cores, indicating that the Miaodao Island uplift experienced further subsidence between 1 and 0.83 Ma, allowing seawater to inundate the central basin of the Bohai Sea during high sea level periods. The current sea-land configuration structure emerged after 0.3 Ma due to the complete subsidence of the Miaodao Islands Uplift. The Quaternary transgressions in the Bohai Sea demonstrate a coupling relationship with the uplift of the Qinghai Tibet Plateau, glacial-interglacial cycles, and integration of the Yellow River. This study traces the initial transgression in the Bohai Sea to 1.35 Ma and provides a new detailed evolutionary model of the timing and routes for the Quaternary transgression of the Bohai Sea and Yellow Sea, thereby enhancing our understanding of sedimentary evolution and paleoenvironmental changes in the region.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"657 ","pages":"Article 112602"},"PeriodicalIF":2.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720601","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":"Paleoenvironmental evolution and East Asian monsoon records through three stages of paleochannels since the mid-pleistocene in the Western Bohai Sea, North China","authors":"Shuyu Wu ,&nbsp;Jun Liu ,&nbsp;Hongxian Chu ,&nbsp;Yongcai Feng ,&nbsp;Meiling Yin ,&nbsp;Lixin Pei","doi":"10.1016/j.palaeo.2024.112603","DOIUrl":"10.1016/j.palaeo.2024.112603","url":null,"abstract":"<div><div>Three stages of paleochannels development, dating back to the Mid-Pleistocene, have been identified in the western Bohai Sea (BS) region. However, the factors controlling their sedimentary formation remain unclear. This study analyzed samples from DZQ01 and adjacent boreholes to establish a chronological framework through AMS ¹⁴C and OSL dating, complemented by grain size and geochemical analyses. End-member analysis using the Generalized Weibull method successfully separated three components: EM1, EM2, and EM3. EM3 (&lt;26.28 μm) reflects the influence of the East Asian Summer Monsoon (EASM), while EM2 (26.28–105.1 μm) is indicative of the East Asian Winter Monsoon (EAWM). Geochemical indicators, such as the Rb/Sr ratio, reflect the impact of paleoclimatic changes. This study identified five major glaciation events since the Mid-Pleistocene. The DU6 unit recorded two glacial stages (300–272 cal. ka B.P.), characterized by a weakened EASM and a stronger EAWM. Similarly, the DU4 unit recorded two glacial stages (165–127 cal. ka B.P.), also marked by a subdued EASM and an enhanced EAWM. The DU2 unit reflects a prolonged glacial stages (71–14 cal. ka B.P.), dominated by the EAWM, resulting in cold and dry conditions. Overall, the uplift of the Tibetan Plateau and sea-level fluctuation significantly influenced the formation and evolution of paleochannels, with the sedimentary characteristics closely tied to the intensities of the East Asian Monsoon (EAM).</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"656 ","pages":"Article 112603"},"PeriodicalIF":2.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660908","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":"A dual bivalve approach for interpreting past sea surface temperatures and seasonality from shell midden sites using oxygen isotope sclerochronology","authors":"Sarah D. Kuehn,&nbsp;Meghan Burchell,&nbsp;Natasha Leclerc","doi":"10.1016/j.palaeo.2024.112585","DOIUrl":"10.1016/j.palaeo.2024.112585","url":null,"abstract":"<div><div>Stable oxygen isotope (δ¹⁸O) analysis of archaeological shellfish remains combined with sclerochronology can be used to precisely reconstruct past sea surface temperature (pSST), season(s) of shellfish collection, and thus the season(s) of archaeological site occupation. Our study tests if δ¹⁸O_shell and sclerochronological analyses of marine bivalve species <em>Leukoma staminea</em> – with previously unassessed seasonality and pSST potential – can provide additional insights not captured by the better studied species, <em>Saxidmous gigantea</em> in British Columbia (BC, Canada). We analyzed live-collected L. <em>staminea</em> and <em>S. gigantea</em> shells from Sechelt, BC, and compared results to archaeological shell data from Powell River, BC, in the territory of the Tla'amin First Nation (1065 to 797 cal. B.P.). The seasonality of shellfish harvest differed between species, with <em>S. gigantea</em> preferentially collected in the spring, whereas L. <em>staminea</em> collected year-round. This highlights that sole-species seasonality studies may miss important variability in harvesting strategies. Additionally, comparisons between instrumental (5.7 to 20.4 °C) and reconstructed SST from modern L. <em>staminea</em> δ¹⁸O_shell (5.6 to 18.4 °C) showed good agreement in annual range. Our results indicate that archaeological <em>S. gigantea</em> record a wider range of pSST (−1.6 to 22.9 °C) than archaeological L. <em>staminea</em> (5.8 to 25.9 °C), suggesting that <em>S. gigantea</em> may be a more sensitive palaeotemperature recorder. Further, we found that using the same reconstructed δ¹⁸O_water value for both species in pSST reconstruction caused an overestimation of temperature. Accordingly, we argue that it is critical to calibrate the equation with corresponding species-specific δ¹⁸O_shell values, regardless of both having aragonite mineral structures. Our study highlights the potential of L. <em>staminea</em> to broaden seasonality interpretations while clarifying that its use for pSST reconstruction may not capture the lower range of temperature.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"657 ","pages":"Article 112585"},"PeriodicalIF":2.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720600","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":"Post-Marinoan paleoredox and paleoproductivity record in Puga cap carbonate: Implication for coastal life colonization at the Amazon Craton marginal Sea","authors":"Renan F. dos Santos ,&nbsp;Pierre Sansjofre ,&nbsp;Afonso C.R. Nogueira ,&nbsp;Simon V. Hohl ,&nbsp;Marlone H.H. Bom ,&nbsp;Ailton S. Brito ,&nbsp;Flavia Callefo ,&nbsp;Stefan V. Lalonde","doi":"10.1016/j.palaeo.2024.112600","DOIUrl":"10.1016/j.palaeo.2024.112600","url":null,"abstract":"<div><div>The geochemical signatures in cap carbonate successions are critical records of paleoceanographic conditions following Snowball Earth events. These deposits offer insight into the shifts in redox conditions and the re-establishment of biogeochemical cycles during postglacial periods, providing a window into the evolving marine environments and potential drivers of early oxygenation. To track redox changes during this transition, we present improved high-resolution analyses of redox proxies across Puga cap carbonate (∼ 635 Ma) on the Southern Amazon Craton, Brazil, allowing for the identification of temporal redox transitions during the post-Marinoan transgression. The depletion of trace elements, particularly redox-sensitive elements (RSEs), such as Mo, U, and V in microbialites formed in basal cap dolostone, was deposited under oxic conditions. Following the initial melting of Marinoan glaciers, microbial mats flourished and grew in a semi-restricted shallow marine environment in the coastal paleoenvironment along the Amazon cratonic margin, where nutrient-rich surface waters fueled primary productivity. In contrast, the increase in RSEs in upper wave-dominated dolostone facies indicates predominantly dysoxic conditions in continuous sea level rise, resulting in the drowning of these early microbial environments and the precipitation of cap limestones. The sequential oxic-dysoxic redox marks the transition from shallow sea to deepening CaCO₃-oversaturated platform conditions. These results demonstrate an unequivocal synchronous relationship between the initial oxygenation of the Amazon margin and the local microbial mat flourishment shortly after the Marinoan glaciation.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"657 ","pages":"Article 112600"},"PeriodicalIF":2.6,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720646","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}