Journal of Palaeogeography最新文献

{"title":"Organic matter accumulation in limestone-marl alternations of the middle Permian Maokou Formation, Sichuan Basin, China, and its response to the interglacial–glacial transition","authors":"Feng-Bin Liu ,&nbsp;Liang-Biao Lin ,&nbsp;Bo-Lin Zhang ,&nbsp;Yu Yu ,&nbsp;Yong Dan ,&nbsp;Si-Yu Liu","doi":"10.1016/j.jop.2025.100312","DOIUrl":"10.1016/j.jop.2025.100312","url":null,"abstract":"<div><div>The deposition of limestone-marl alternations (LMAs) with elevated organic matter (OM) content within the Middle Permian (Guadalupian) Maokou Formation of the Sichuan Basin, China, was influenced by the interglacial–glacial transition. However, the mechanisms of OM accumulation remain unclear. This study examines OM accumulation in the first member of the Maokou Formation (i.e., the Mao I Member) from the Hegou and Zaodu sections using multiple geochemical proxies, with a focus on its response to climatic shifts during the interglacial–glacial transition. OM accumulation was primarily influenced by this climatic transition through two interrelated processes: (1) by regulating the intensity of chemical weathering (Rb/Sr) in nearshore shallow-platform environments, which in turn controlled terrigenous nutrient input (Ti/Al); and (2) by enhancing upwelling in distal deeper waters (Cd/Mo), thereby stimulating primary productivity (OCAR, PAR, Cu_XS, and Ni_XS). These mechanisms overcame the typical constraints of an oxygenated carbonate platform setting (where Ce anomalies are mostly &lt;1.3), exerting a stronger control on OM accumulation than redox conditions. As glacial conditions intensified, the dominant mode of OM accumulation in the Mao I Member shifted from a detrital-driven regime—characterized by high terrigenous input (Ti/Al) and clay-mediated preservation (Al₂O₃)—to a hybrid system jointly regulated by both detrital input and upwelling-related nutrient delivery (Cd/Mo). In this latter phase, enhanced upwelling compensated for the decline in terrigenous nutrients. OM accumulation persisted even under oxygenated bottom-water conditions. This finding contrasts with the anoxia-dependent models typical of high OM shales and underscores the predominance of productivity over preservation factors in this icehouse carbonate platform. The transition toward glacial conditions is evidenced by the decreasing Rb/Sr ratios, indicating weakened chemical weathering, and declining Ti/Al ratios, signifying reduced terrigenous input. Our findings elucidate how multi-factor interactions govern OM accumulation in mixed carbonate–clastic systems and provide valuable constraints for predicting the stratigraphic distribution and quality of potential hydrocarbon source rocks in such settings.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"15 1","pages":"Article 100312"},"PeriodicalIF":2.0,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Grallatorid–eubrontid tridactyl track assemblages from Lower Jurassic, Sichuan Province, China: Insights into theropod diversity, locomotion and behavior","authors":"Li-Da Xing ,&nbsp;Shan Jiang ,&nbsp;Qi-Yan Chen ,&nbsp;Yong Ye ,&nbsp;Guang-Zhao Peng ,&nbsp;Anthony Romilio ,&nbsp;Hendrik Klein ,&nbsp;Yan-Yi Gong","doi":"10.1016/j.jop.2025.100311","DOIUrl":"10.1016/j.jop.2025.100311","url":null,"abstract":"<div><div>The Sichuan Basin in southwestern China is home to the most extensive theropod track record in the Lower Jurassic of China, comprising a range of minute-to medium-sized tracks that form the grallatorid–eubrontid (GE) plexus. The majority of these had previously been discovered in the Ma’anshan Member of the Ziliujing Formation. New material described herein is from the Wuli tracksite that suggests a flourishing paleoecological scene in a temporary waterfront habitat. Upon reviewing the GE plexus at different scales, we consider the locomotion style of these early theropod trackmakers, which likely included the ‘grounded-running’ gait of extant birds, as well as the possibility of a tail trace that may be related to intra- or interspecific interactions.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"15 1","pages":"Article 100311"},"PeriodicalIF":2.0,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Jurassic manganese microbial carbonates of West Siberian oil and gas basin: Diagnostic features, environmental sedimentation, secondary transformations","authors":"Latypova Margarita ,&nbsp;Gafurova Dina ,&nbsp;Churkina Valeria ,&nbsp;Kalmykov Anton ,&nbsp;Kalmykov Georgy","doi":"10.1016/j.jop.2025.100316","DOIUrl":"10.1016/j.jop.2025.100316","url":null,"abstract":"<div><div>This study focuses on the investigation of Late Oxfordian–Early Tithonian manganese microbial carbonates (MC) found at the top of the Georgiev regional stage in the Western Siberian oil and gas basin. In some isolated areas, these MC are oil reservoirs. However, these rocks are still one of the least studied sediments in the carbonate interval at the boundary of the Bazhenov and Georgiev subregional stage. We have described their geochemical, lithological and mineralogical composition in detail. Based on the characteristics of MC, we assumed their formation settings. The elevated MnO content, associated with microbial processes, and the high concentration of biophilic elements, both suggest the active involvement of organic matter in the formation and development of microbial sediments. The isotopic composition of carbon in the microbial carbonates further supports a biogenic source of carbon dioxide playing an important role in the formation of these deposits. We have established that the Late Jurassic manganese MC were intensely secondary altered, partially recrystallized and calcified by catagenetic processes. Isometric pyrite crystal aggregates with kutnohorite fragments were formed at the contacts between kutnohorite and calcite zones. We suggest that the presence of caverns and high reservoir potential in the microbial carbonates from the Yem-Egovskaya field of the Krasnoleninsky arch may be attributed to intense secondary catagenetic alterations.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"15 1","pages":"Article 100316"},"PeriodicalIF":2.0,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Middle Devonian stromatoporoid-dominated reefs at Maoying, South China: New insights into age, biotic turnover and palaeogeographical model","authors":"Jia-Yuan Huang ,&nbsp;Wen Guo ,&nbsp;Yu-Cong Sun ,&nbsp;Wen-Kun Qie","doi":"10.1016/j.jop.2025.100315","DOIUrl":"10.1016/j.jop.2025.100315","url":null,"abstract":"<div><div>Middle Devonian was the time for extensive reefs across South China, but their importance in understanding the development of reef communities was undervalued. This study described the lithological and palaeontological features of the Middle Devonian reef deposits at Maoying Town, Guizhou Province, South China. Two different units are recognised based on five road-cut exposures. The lower unit is characterised by argillaceous limestone, yielding a variety of auto-to autoparabiostromes. The biostromes are dominated by morphologically diverse stromatoporoids, including <em>Gerronostromaria</em>, <em>Salairella</em>, <em>Synthetostroma</em>, and <em>Stachyodes</em>, with subordinate roles of tabulate corals, rugose corals, chaetetids, bryozoans, brachiopods, gastropods, bivalves, and tubeworms. The upper unit consists mainly of parabiostromes, characterised by abundant dendroid and bulbous stromatoporoids (<em>Amphipora</em>, <em>Stachyodes</em>, and <em>Actinostroma</em>), along with leperditicopid ostracods, parathuramminid foraminifers, and calcispheres. The environments of these two units are interpreted to be open marine and back-reef to lagoonal environments, respectively. Newly recognised icriodid and bipennatid conodonts from the lower unit and brachiopod <em>Stringocephalus</em> in the upper unit indicate a Givetian age of the entire succession, pushing back the age of the latter from Frasnian of the previous thought. Comparison with nearby two sections possibly reflects a palaeogeographical turnover from ramp to carbonate platform. This study sheds light on understanding how reef communities changed in relation to environmental conditions in South China during the expansion of global Givetian reefs.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"15 1","pages":"Article 100315"},"PeriodicalIF":2.0,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palaeogeography and its controls on organic carbon accumulation in the Wufeng–Longmaxi formations of Chongqing, southeastern Sichuan Basin, southwestern China","authors":"Yan-Wen Shao ,&nbsp;Feng-Hua Zhao ,&nbsp;Feng-Xian Jin ,&nbsp;Zhen-Sheng Shi ,&nbsp;Qun Zhao ,&nbsp;Shi-Long Kang ,&nbsp;Long-Yi Shao","doi":"10.1016/j.jop.2025.100314","DOIUrl":"10.1016/j.jop.2025.100314","url":null,"abstract":"<div><div>The Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation are important target strata for shale gas exploration in the Sichuan Basin, China. In this paper, the sedimentary facies and palaeogeography of the two formations in Chongqing area have been analyzed, and total organic carbon (TOC) contents are correlated with the sedimentary facies to prospect the favorable areas for shale gas exploration. According to the lithological characteristics and sedimentary structures, five sedimentary facies are identified, i.e., siliceous deep-water shelf, muddy deep-water shelf, calcareous shallow-water shelf, muddy shallow-water shelf, and silty-muddy shallow-water shelf facies, respectively. The palaeogeography reconstruction is based on the lithological distribution in the study area. The lower part of Wufeng Formation was developed with the muddy deep-water shelf, siliceous deep-water shelf, and calcareous shallow-water shelf facies. The Guanyinqiao Member, representing the upper part of Wufeng Formation, was developed with the transition from siliceous deep-water shelf and muddy deep-water shelf facies to a domination of muddy shallow-water shelf and calcareous shallow-water shelf facies, which was deposited during the glacial-induced global regression. The Lower Member of Longmaxi Formation was characterized by the expansion of siliceous deep-water shelf facies and contraction of muddy shallow-water shelf and calcareous shallow-water shelf facies, signifying a rapid sea level rise associated with global warming. The Upper Member of Longmaxi Formation was developed with muddy shallow-water shelf facies, with the expansion of calcareous shallow-water shelf and silty-muddy shallow-water shelf facies. The shales with higher TOC content tend to be developed in the siliceous deep-water shelf and muddy deep-water shelf facies that were distributed in the Nanchuan, Shizhu, Yongchuan, and Wuxi areas. The results of lithofacies palaeogeography reconstruction have a certain significance to predict shale-gas target areas in Wufeng and Longmaxi formations of Chongqing.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"15 1","pages":"Article 100314"},"PeriodicalIF":2.0,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First record of Araucaria with leafy shoots and reproductive organs from the Lower Cretaceous of NW China and its historical biogeography","authors":"Ai-Jing Li ,&nbsp;Bao-Xia Du ,&nbsp;Jing Zhang ,&nbsp;Jing Peng ,&nbsp;Ming-Chen Zhang ,&nbsp;Pei-Hong Jin ,&nbsp;Shao-Hua Lin ,&nbsp;Yi-Qiao Fu ,&nbsp;Jing-Jing Cai","doi":"10.1016/j.jop.2025.100310","DOIUrl":"10.1016/j.jop.2025.100310","url":null,"abstract":"<div><div>The modern Gondwanan genus, <em>Araucaria</em>, exhibited a worldwide distribution during its early evolution in the late Mesozoic. However, the scarcity of fossil records restricted exploring its early radiation and evolution. A new species, <em>Araucaria gansuensis</em> sp. nov. was described based on well-preserved leafy shoots associated with female cones, deciduous pollen cones and bract-scale complexes from the Lower Cretaceous in Northwest China. Maximum parsimony analysis revealed that the phylogenetic position of <em>A. gansuensis</em> is within the basal clade of Sect. <em>Eutacta</em>. Moreover, palaeobiogeographic analysis suggested that <em>Araucaria</em> possibly originated in the low latitudes of the Pangea and formed differentiation centers in Laurasia (East Asia) and Gondwana (South America) in the Middle Jurassic. Furthermore, with the breakup of Pangea, <em>Araucaria</em> rapidly radiated globally, and exhibited a more extensive distribution in the Northern Hemisphere during the Cretaceous. The discovery of <em>A. gansuensis</em> as a significant representative has unveiled a pathway for the dispersion of <em>Araucaria</em> in East Asia and Europe. Subsequently, <em>Araucaria</em>, which belonged to a more primitive lineage, started declining and facing extinction in the Northern Hemisphere in the Early Paleocene due to factors such as geographic isolation, climatic variations, and expansion and dominance of angiosperms.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"15 1","pages":"Article 100310"},"PeriodicalIF":2.0,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organic lithofacies and its reservoir characteristics of lacustrine shales of the Dongyuemiao Member in the Jurassic Ziliujing Formation, eastern Sichuan Basin","authors":"Ming-Yang Wei ,&nbsp;Wang Chen ,&nbsp;Xing-Zhi Wang ,&nbsp;Zhi-Dong Bao ,&nbsp;De-Ming Zeng ,&nbsp;Jia-Hao Kang ,&nbsp;Yang Li ,&nbsp;Kai-Ming Liu ,&nbsp;Fei Huo","doi":"10.1016/j.jop.2025.100309","DOIUrl":"10.1016/j.jop.2025.100309","url":null,"abstract":"<div><div>This study investigates the reservoir properties and main controlling factors of different organic lithofacies in the Jurassic Dongyuemiao Formation lacustrine shales, eastern Sichuan Basin. Based on lithofacies classification, the spatial characteristics and physical properties of the reservoirs, along with the primary controlling factors, were analyzed using core observation, scanning electron microscopy (SEM), low-temperature nitrogen adsorption, and other techniques. The results indicate that: 1) In the eastern Sichuan Basin, the Dongyuemiao Member is predominantly composed of clay minerals and quartz, which are the main mineral constituents of the lacustrine shales. Minor amounts of calcite, feldspar, dolomite, pyrite, and rhodochrosite are also present. Four main lithofacies were identified within the study area: argillaceous shale with high-medium TOC (Ⅰ₂), mixed shale with low-medium TOC (Ⅱ₁), sacrilegious-silt mixed shale with medium-low TOC (Ⅱ₂), and argillaceous siltstone with low TOC (Ⅲ₂). 2) The shale microstructure is characterized by micropores, primarily comprising intergranular pores between clay minerals and organic-matter pores. Intragranular dissolution pores, notably within shell fragments, are locally developed. Microfractures are mainly observed as intra-layer shale fractures and fractures along the edges of shell fragments. 3) High organic matter abundance (&gt;1 %), high clay mineral content (&gt;40 %), and moderate carbonate mineral content (&lt;10 %) in the shale of the study area contribute to the development of pores. In contrast, high quartz and feldspar mineral content (&gt;50 %) and excessively high (&gt;12 %) or low (&lt;8 %) carbonate mineral content inhibit shale pore development. 4) A comprehensive analysis shows that the argillaceous-silt mixed shale with medium-low TOC (Ⅱ₂) is the most favorable lithofacies for reservoir development, followed by argillaceous shale with high-medium TOC (Ⅰ₂). The mixed shale with lower-medium TOC (Ⅱ₁) is less favorable, and the argillaceous siltstone with low TOC (Ⅲ₂) is the poorest. Considering the vertical distribution of lithofacies in the Dongyuemiao Member, it is concluded that the middle-upper part of the Dong 2 submember is the most prospective reservoir interval in the study area.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"15 1","pages":"Article 100309"},"PeriodicalIF":2.0,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sedimentology, provenance, and paleoclimate of Jurassic–Cretaceous red beds: Example from the southern front of the Central High Atlas and Northern Preafrican Trough, Morocco","authors":"Said Adardor ,&nbsp;Hicham Nasri ,&nbsp;Hamid Haddoumi ,&nbsp;Radouan El Bamiki ,&nbsp;Rachid Chennouf ,&nbsp;Hanane Miri","doi":"10.1016/j.jop.2025.100299","DOIUrl":"10.1016/j.jop.2025.100299","url":null,"abstract":"<div><div>Five stratigraphic sections from the Aghbalou N'Kerdouss–Tadighoust area were analyzed using integrated petrographic, granulometric, calcimetric, and mineralogical approaches applied to both bulk samples and clay fractions. The findings reveal a transitional depositional environment shaped by a dynamic interplay of continental and restricted marine influences, particularly within the Ifezouane Formation (Member 2), which reflects low-amplitude sea-level oscillations under confined paleoenvironmental conditions. Whole-rock mineralogy is dominated by quartz, K-feldspar, plagioclase, hematite, calcite, dolomite, siderite, and gypsum. The associated clay mineral assemblages comprise illite, kaolinite, smectite, and chlorite, with compositional variability across sections. Illite crystallinity and illite chemistry index data indicate a dual provenance, with sediment sources originating from both the Anti-Atlas and Sahara regions to the south, as well as the Jurassic uplands to the north. These interpretations are supported by petrographic evidence and mineralogical signatures. Furthermore, the mineralogical data suggest that arid to semi-arid climatic conditions and/or tectonic activity played a significant role during deposition. This study demonstrates how the integration of clay mineral signatures with petrography, grain-size distribution, and calcimetric data offers a reliable basis for reconstructing provenance, unraveling paleoenvironmental conditions, and refining palaeogeographic reconstructions of peri-Tethyan basins, while also providing a comparative framework applicable to analogous red bed systems worldwide.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"15 1","pages":"Article 100299"},"PeriodicalIF":2.0,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of smectite-illitization and hydrocarbon generation on the pore structure: a case study from the continental shales in China","authors":"Dan-Ting Luo ,&nbsp;Jing Zhang ,&nbsp;Jing-Lan Luo ,&nbsp;Zi-Hui Feng ,&nbsp;Chao Deng ,&nbsp;Yu-Bin Bai ,&nbsp;Hong-Mei Shao ,&nbsp;Min Yan ,&nbsp;Ze Tan","doi":"10.1016/j.jop.2025.100298","DOIUrl":"10.1016/j.jop.2025.100298","url":null,"abstract":"<div><div>Pore structure of shale significantly affects the occurrence and reserves of natural gas and oil. At present, the quantitative characterization of pore structure related to clay minerals in high-clay continental shale remains inadequate. The mechanism of clay mineral transformation and pore preservation of continental shale is still unclear. To address this gap, an organic-rich, high-clay shale from the first member of the Qingshankou Formation (K₂qn₁) in the Gulong Sag, Songliao Basin, China, was analyzed, based on the measurement of argon ion polishing-field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), total organic carbon (TOC), vitrinite reflectance (Ro), pore structure parameters, and fractal dimension obtained from the isothermal N₂ adsorption experiment, integrated with well logging data. Quantitative characterization of the modification on shale pore structure by smectite illitization and hydrocarbon generation from organic matter was conducted. The primary factors influencing pore structure, and pore preservation mechanism were then elucidated. Research result shows that the mesopores (2–50 nm) formed during smectite illitization and micropores (&lt;2 nm) produced by hydrocarbon generation from the organic matters significantly contributed to the pore volume and specific pore surface area of the shale. The microcrystalline quartz, formed in the smectite illitization, caused the loss of some pores, but the rigid frame composed of the microcrystalline quartz, as well as the overpressure generated partly by hydrocarbon generation from organic matter and partly by smectite-to-illite transformation, preserved some pores. This work highlights that smectite illitization and hydrocarbon generation from organic matter are crucial mechanisms for pore formation and preservation in continental shale with a high content of clay minerals.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"15 1","pages":"Article 100298"},"PeriodicalIF":2.0,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145322714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cryo-paleosols and paleoclimate/cosmic archives in the Dry Valleys, Antarctica","authors":"William C. Mahaney ,&nbsp;Peeter Somelar","doi":"10.1016/j.jop.2025.100291","DOIUrl":"10.1016/j.jop.2025.100291","url":null,"abstract":"<div><div>Perhaps the most obscure and overlooked paleoenvironmental resource in Antarctica is the cryosol-paleosol record of the Dry Valleys, and the cryo-stratigraphy of the Palmer Peninsula, East Antarctica, and the islands. The Scientific Committee on Antarctic Research (SCAR) Committee in 2014 outlined a forward look for new initiatives and of the six priorities, the ‘Reveal Antarctica’s History’ focused on ‘rock and sediment records to know whether past climate states are fated to be repeated’. Of all the records available to us across the continent, the thinnest and most obscure, are found within cryo-paleosols and accompanying clastic rinds, the latter often embedded in pavements capping these ancient sentinels. An ancient pedostratigraphy, extending horizon group-to-horizon group reported here, offers unexpectedly strong post-∼15 Ma weathering and salt accumulation, interrupted by a recent airburst, presumably the BM (black mat) of 12.8 ka. Evidence for a cosmic event comes in the form of melted/welded, air-quenched, dendritic, Pt (Ir) coated, organic-fused grains and highly sheaved and plate-uplifted mineral surfaces. As shown here, Antarctic paleosols, housing both oxidized and Na-encrusted beds, shed light not only on paleoclimatic/ecologic histories that might be repeated, but this one cometary occurrence, reported for the first time in any Dry Valley paleosols, may well occur again, the next time with enough energy to destroy Earth’s atmosphere.</div></div>","PeriodicalId":100819,"journal":{"name":"Journal of Palaeogeography","volume":"14 4","pages":"Article 100291"},"PeriodicalIF":2.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}