Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Asynchronous uplift of the South and Central Tian Shan in the Mesozoic: Insights from detrital zircon geochronology on the Southern Tian Shan Foreland Basin (NW China)","authors":"Kaixun Zhang ,&nbsp;Ronghu Zhang ,&nbsp;Zhiyuan He ,&nbsp;Tao Qian ,&nbsp;Qinglu Zeng ,&nbsp;Ke Wang ,&nbsp;Chao Li","doi":"10.1016/j.palaeo.2025.112980","DOIUrl":"10.1016/j.palaeo.2025.112980","url":null,"abstract":"<div><div>The Tian Shan orogenic belt, Earth's largest active intracontinental mountain belt, has experienced multiple reactivation and uplift events since its late Paleozoic amalgamation. However, the mechanisms driving these processes, as well as the relative uplift timing and rates of its secondary tectonic units, such as the South Tian Shan (STS) and Yili Block-Central Tian Shan (Yili-CTS), remain unclear. To investigate these issues, we analyzed detrital zircon U<img>Pb isotopic ages and heavy mineral assemblages from late Paleozoic to Cenozoic sedimentary rocks in the Southern Tian Shan Foreland Basin (STFB) using deep drilling samples. Our results document distinct detrital zircon responses to three major reactivation events during the Mesozoic–Cenozoic. In the late Triassic, detritus from the Yili-CTS first reached the STFB, likely due to enhanced erosion linked to a megamonsoon. By the early Cretaceous, the Yili-CTS had become a dominant sediment source, although its contribution declined in younger formations, indicating a delayed uplift of the STS relative to the Yili-CTS. These observations suggest that the Mongol-Okhotsk orogeny might trigger the early Cretaceous uplift of the Yili-CTS, with subsequent remote effects from the Lhasa–Qiangtang collision driving the STS’s uplift. Since the late Paleogene, uplift and shortening have been concentrated along the mountain front thrust-fold belts, blocking sediment transport from the Yili-CTS to the STFB, while tectonic quiescence in earlier periods allowed for increased contributions of the Yili-CTS-derived sediments, reflecting the overall planation of the Tian Shan. These findings provide new insights into the topographic evolution of the Tian Shan during multiple phases of intracontinental orogenesis and highlight the interactions between regional tectonics and far-field geodynamic forces.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"671 ","pages":"Article 112980"},"PeriodicalIF":2.6,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899667","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":"Periglacial aeolian activities in the Headwater Region of the Yellow River, northeastern Tibetan Plateau","authors":"Jingjing Hu ,&nbsp;Guangyin Hu ,&nbsp;Linhai Yang ,&nbsp;Xueyang Guo ,&nbsp;Jingran Zhang ,&nbsp;Zhibao Dong","doi":"10.1016/j.palaeo.2025.112984","DOIUrl":"10.1016/j.palaeo.2025.112984","url":null,"abstract":"<div><div>The Headwater Region of the Yellow River (HRYR) situated in the northeastern part of the Tibetan Plateau (TP) at an average elevation of over 4300 m, experienced extensive glaciation during the Last Glacial Period. However, the relationship between glacial presence and aeolian activity in this periglacial region remains poorly understood. To investigate this, three sediment sequences from a blowout in the periglacial region of HRYR were selected for sampling. The coarse-grained (CG) K-feldspar pIRIR dating was employed to establish the chronology, yielding 16 luminescence ages that ranged from 16.35 ± 0.96 ka to 60 ±  1 a. The results indicate that the earliest aeolian deposits occurred during the Last Deglaciation, with aeolian deposits also recorded in the early Holocene. During the mid-Holocene, there was a gap in aeolian sedimentation, which may be due to humid climatic conditions. In the late Holocene, drier and cooler climatic conditions triggered a resurgence of rapid aeolian deposition. A depositional gap between 2.5 and 0.6 ka in this period likely reflects erosional events under high wind energy conditions. Aeolian activity during the Last Deglaciation was closely linked to the periglacial environment at the sampling site. As the glaciers receded, the moraine deposits from the Bayan Har Mountains were reworked by rivers and exposed during the dry seasons, providing source material for the localized aeolian activity in the region. This study aims to provide the influence of periglacial environment on aeolian activity and establishes a framework for understanding aeolian deposition in high altitude glacial environments.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"671 ","pages":"Article 112984"},"PeriodicalIF":2.6,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899669","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":"Surface soil phytolith assemblages across arid and semi-arid regions of northern China, and their implications for quantitative reconstruction of precipitation","authors":"Yuhan Kuai,&nbsp;Shipei Dong,&nbsp;Zhuolun Li,&nbsp;Xiang Li,&nbsp;Jiaqi Wang","doi":"10.1016/j.palaeo.2025.112979","DOIUrl":"10.1016/j.palaeo.2025.112979","url":null,"abstract":"<div><div>Clarifying the environmental significance of proxies and establishing a reliable function between regional climate variables and proxies can enhance the accuracy of quantitative precipitation reconstruction, which is benefit for revealing global climate change and their regional environmental responses. However, the links between surface soil phytolith assemblages and precipitation changes in arid and semi-arid regions remain unclear. In this study, we conducted gridded sampling (0.5° × 0.5°) of 41 surface soil samples across a precipitation gradient of 50–400 mm in the arid and semi-arid regions of northern China for phytolith analysis. The results showed that the phytolith morphotypes could be classified into 11 morphotypes, dominated by Gobbet, E<span>longate entire</span>, and R<span>ondel</span>. Cluster analysis indicated that the surface soil phytolith assemblages effectively reflect local vegetation. Redundancy analysis (RDA) revealed that, compared to mean annual temperature (MAT), potential evapotranspiration (PET) and wind speed (WS), mean annual precipitation (MAP) is the dominant variable controlling the spatial distribution of phytoliths. C<span>renate</span> and B<span>locky</span> were positively correlated with MAP, while Gobbet was negatively correlated with MAP. A new phytolith index PI = (C<span>renate</span> + B<span>locky</span>) / (C<span>renate</span> + B<span>locky</span> + Gobbet) and a transfer function between the PI index and MAP (MAP = 613.33 × PI +33.36, R² = 0.8, RMSE = 46 mm) were established. The PI index is more suitable as a proxy for paleoclimate reconstruction in this region compared to previous indices such as Iph. The PI-MAP transfer function demonstrates high accuracy in potential applications in quantitative reconstruction of precipitation in arid and semi-arid regions. This study provides valuable quantitative estimates of paleo-precipitation changes in arid and semi-arid regions.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"671 ","pages":"Article 112979"},"PeriodicalIF":2.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888205","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":"Paleoenvironment fluctuations and conodont size variations in the Baoshan block of eastern Tethys: implications for the late Norian warming event (Late Triassic)","authors":"Bao Guo ,&nbsp;Yixing Du ,&nbsp;Xin Jin ,&nbsp;Tetsuji Onoue ,&nbsp;Honami Sato ,&nbsp;Yuki Tomimatsu ,&nbsp;Lu Han ,&nbsp;Zhiqiang Shi ,&nbsp;Yuehan Sun ,&nbsp;Qiangwang Wu ,&nbsp;Manuel Rigo","doi":"10.1016/j.palaeo.2025.112983","DOIUrl":"10.1016/j.palaeo.2025.112983","url":null,"abstract":"<div><div>The Norian Stage of the Late Triassic represents a significant interval in geological history marked by environmental and biological evolutions. One notable event during this time is the late Norian warming event (W3), occurring in the late Norian. Globally recorded, the warming event is associated with carbon cycle perturbations, temperature increases, changes in biodiversity, and enhanced weathering intensity. Previous studies have focused on carbon isotopes, sedimentology, and biostratigraphy in the Baoshan block. However, information on environmental changes in this area during the Norian Stage remains limited. In this study, we utilized redox conditions indexes (V/Cr, U/Th, Mo_EF/U_EF, and Ce/Ce^⁎) and paleo-productivity proxies (P_org, Ba_xs) to reconstruct the ocean paleoenvironment in the HYB section of the Baoshan block. Two stages of reducing conditions and paleo-productivity fluctuations were identified during the late Norian warming event interval. In addition, the size of 1606 well-preserved adult conodont pectiniform elements from the HYB section was measured. The mean length of conodonts increased before the Alaunian-Sevatian boundary and then decreased significantly after the boundary in the Sevatian. Conodont size variations are typically related to changes in living environments, but our study found no direct relation between changes in redox conditions, paleo-productivity, and variations in conodont size in the Baoshan block. It may be due to the predominant conodont fauna, <em>Mockina</em>, being surface water dwellers. These surface-dwelling conodonts were not influenced by changes in seafloor redox conditions in relatively deep water. The direct evidence is instead that the size variation of conodonts is more likely affected by temperature changes in Tethyan surface seawater during the late Norian warming event.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"671 ","pages":"Article 112983"},"PeriodicalIF":2.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895699","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":"Skeletal accumulations of the parareptile Procolophon trigoniceps reflect fossorial response to Early Triassic climatic instability across southern Gondwana","authors":"Roger M.H. Smith ,&nbsp;Frederik P. Wolvaardt ,&nbsp;Juan C. Cisneros ,&nbsp;Felipe L. Pinheiro ,&nbsp;Joseph J. Bevitt ,&nbsp;Julien Benoit","doi":"10.1016/j.palaeo.2025.112978","DOIUrl":"10.1016/j.palaeo.2025.112978","url":null,"abstract":"<div><div>The Lower Triassic parareptile <em>Procolophon trigoniceps</em> is known from hundreds of specimens, mostly from upper Katberg Formation of the South African Karoo, where it co-occurs with the dicynodont <em>Lystrosaurus declivis</em> and the diminutive temnospondyl <em>Micropholis.</em> The same taxon also occurs in the lower-mid Triassic Fremouw Formation of Transantarctic Basin and the coeval Sanga do Cabral Formation of Paraná Basin in Brazil. The Gondwana-wide distribution of <em>P. trigoniceps</em> raises questions as to how they so successfully colonised southern Gondwana and why their fossils occur in hyper-abundant skeletal concentrations.</div><div>We investigated the sedimentology and taphonomy of <em>P. trigoniceps</em> accumulations in South Africa, Brazil and Antarctica to determine the cause of such exceptional preservation. South African localities are mainly red mudrock with horizons of micrite nodules, some of which contain up to five fully- and partially articulated skeletons, commonly of adult and juveniles in bone-on-bone contact lying side-by-side, criss-crossing, or in curled-up poses. In situ cylindrical scratch-marked decline burrow casts occur in the same outcrops. Neutron tomography of a scratch-marked burrow cast revealed a curled-up adult and disarticulated juvenile. Rare, but notable, tooth puncture marks occur on some articulated specimens. The Antarctic specimens occur in only slightly rubified mudrock and have similar adult-juvenile associations although not within nodules. Cylindrical <em>Reniformichnus</em> burrow casts are also present. The Brazilian specimens are mostly disarticulated elements within lenses of intraformational conglomerate, however, some articulated specimens have recently been found in calcareous nodules.</div><div>The general palaeoenvironment of all the <em>P. trigoniceps</em> bearing intervals is of warm drought-and-deluge prone floodplains between low sinuosity anastomosing channels close to ephemeral ponds and further evidence for continued Gondwana-wide climatic instability following the end-Permian mass extinction. The taphonomic evidence supports previous suggestions that <em>P. trigoniceps</em> was a group-living, possibly communal, fossorial reptile analogous in its life habits to <em>Gopherus agassizii</em>, an extant North American desert tortoise<em>.</em></div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"672 ","pages":"Article 112978"},"PeriodicalIF":2.6,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143913139","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":"HORSE: Harmonize regional and global stratigraphic records through horizon sequencing","authors":"Tianyi Chu ,&nbsp;Hanhui Huang ,&nbsp;Junxuan Fan ,&nbsp;Yiying Deng ,&nbsp;Tao Xu ,&nbsp;Chao Qian ,&nbsp;Ke Xue ,&nbsp;H. David Sheets ,&nbsp;Michael H. Stephenson ,&nbsp;Yukun Shi ,&nbsp;Xudong Hou","doi":"10.1016/j.palaeo.2025.112976","DOIUrl":"10.1016/j.palaeo.2025.112976","url":null,"abstract":"<div><div>A uniform, high-resolution geological timescale is essential for studying Earth's history, including the dynamics of biodiversity and environmental change. Quantitative stratigraphy combines stratigraphic data with statistical and computational approaches into a global timescale that allows them to be correlated simultaneously. For example, Constrained Optimization (CONOP), built upon Graphic Correlation, sequences geological events to generate a composite sequence by resolving inconsistencies among stratigraphic records. However, CONOP determines only the global order of events (e.g., first or last appearances of species) and cannot assign ages to local records, e.g., a locally observed fossil occurrence. Horizon Annealing (HA) addresses this by using a simulated annealing algorithm to sequence sampling “horizons” while preserving local stratigraphic details. Here, we report HORizon SEquencing (HORSE), a generalized and optimized method for HA, with an implementation including parallel computing and genetic algorithms to enable fast, automatic stratigraphic correlation on large datasets. We evaluate HORSE, HA, and CONOP on three datasets—two empirical and one simulated—and assess their performance in terms of accuracy, efficiency, and robustness. HORSE greatly outperforms HA in computational efficiency and performs comparably to CONOP in event sequencing with greater robustness. Beyond constructing high-resolution geological timescales or life histories in deep time, HORSE uniquely preserves local stratigraphic information, enabling applications in palaeogeographical or palaeoecological studies, as well as evaluations of preservation and sampling biases—capabilities not possible with CONOP.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112976"},"PeriodicalIF":2.6,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875039","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":"Palynological assemblages from the 2nd tectono-sedimentary cycle of the Southern Alps: New constraints for the onset of the Alpine cycle and regional-global inferences","authors":"A. Spina ,&nbsp;E. Capezzuoli ,&nbsp;N. Gretter ,&nbsp;L. Marchetti ,&nbsp;C. Corradini ,&nbsp;N. Degl'Innocenti ,&nbsp;R. Scarani ,&nbsp;A. Ronchi","doi":"10.1016/j.palaeo.2025.112973","DOIUrl":"10.1016/j.palaeo.2025.112973","url":null,"abstract":"<div><div>Analysis of palynological assemblages from the Val Daone Conglomerate (VDC) Formation (central Southern Alps) provides significant new information on the age of this lithostratigraphic unit and, therefore, of the inception of the Permian tectono-stratigraphic cycle 2 (TSU2) in the Southern Alps. The VDC Formation represents a nearly 100-m thick, medium-grained fluviatile body which can be followed in western Trentino, from the NE part of the Permian Collio Basin to the west, up to the Val Rendena to the east.</div><div>Palynomorphs from the VDC Formation are well- preserved in the Val di Scale (Val Rendena) section but poorly preserved in the Ronchi section (Val Daone). Comparisons between the results of the present study with data from the Tregiovo, Val Gardena Sandstone and Bellerophon formations of the Italian Southern Alps reveal a sequence of distinct associations that are stratigraphically and perhaps palaeoenvironmentally controlled. The stratigraphy of the palynomorph assemblage of the VDC is diagnostic of the late Capitanian-Wuchiapingian. Two different palynozones within the Val Daone Conglomerate PalynoZone - VDCPZ are established from the VDC Formation, the lower (VDCPZ1) from the Ronchi section, attributed to late Capitanian-early Wuchiapingian, and the upper (VDCPZ2) from the Val Rendena section, of Wuchiapingian age. These VDCPZs show close similarities with coeval associations recorded from other European areas. This is consistent with the stratigraphic position of the VDC Formation and allow us: 1) to assign the beginning of the Permian 2nd tectono-sedimentary cycle in this sector of the Southern Alps to the late Capitanian-early Wuchiapingian and 2) to suggest that the depositional hiatus caused by the intra-Permian tectonics straddled most of the Guadalupian and it is partly time-equivalent with the Pangaea gap. Moreover, the VDCPZ1 is one of the few low-latitude associations that are time-equivalent or slightly younger than the end-Guadalupian mass extinction, a major climate-driven event that significantly changed terrestrial faunas.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"674 ","pages":"Article 112973"},"PeriodicalIF":2.6,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089547","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 simple climate-driven semi-mechanistic vegetation model can explain the pan-Asian extent of the glacial mammoth steppe","authors":"Lisa Merkens ,&nbsp;Tim Anders ,&nbsp;Wolfgang Traylor ,&nbsp;Hervé Bocherens ,&nbsp;Thomas Hickler","doi":"10.1016/j.palaeo.2025.112962","DOIUrl":"10.1016/j.palaeo.2025.112962","url":null,"abstract":"<div><div>Graminoid and forb tundra vegetation has been hypothesized to have covered a vast area in northern Eurasia during the Late Pleistocene cold phases, providing habitat for many now-extinct megaherbivores. The formation and persistence of this now nearly-lost vegetation have been either attributed to the cold and arid climate of the glacials (climate hypothesis) or the action of its large herbivores (keystone herbivore hypothesis). Here, we test whether the extent of this plant community can be modelled mechanistically using a few bioclimatic variables with clear physiological effects on plants. We fitted the bioclimatic limits based on the distribution of the closest modern analogues of the graminoid-forb-tundra. Next, we applied this parameterization to conditions of the Last Glacial Maximum, given by the gridded climate-model-based CHELSA-TraCE21k paleoclimate dataset. The projected glacial distribution of the graminoid and forb tundra mainly expands in central Siberia. The model failed to reproduce fossil-inferred occurrences of graminoid and forb tundra in glacial Europe and northern Eurasia, however, possibly because of inaccuracies in CHELSA-TraCE21k, with temperatures being too high in Europe and too low in northern Siberia. This initial study suggests that climate might have played a substantial role in forming the glacial graminoid and forb tundra, but analyses with more climate models will be necessary to corroborate this finding. Our parsimonious, transparent, and process-based model holds the potential for testing the climate hypothesis more rigorously with additional and improved palaeoclimate data.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112962"},"PeriodicalIF":2.6,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876876","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":"Palaeoglacial and palaeoclimate inferences from cirque morphometry and spatial distribution across northern Patagonia (40o – 45o S)","authors":"R.L. Soteres ,&nbsp;D.A. Cabrera ,&nbsp;M.A. Martini ,&nbsp;E.A. Sagredo ,&nbsp;J. Pedraza ,&nbsp;R.M. Carrasco ,&nbsp;M.R. Kaplan ,&nbsp;J.M. Araos","doi":"10.1016/j.palaeo.2025.112939","DOIUrl":"10.1016/j.palaeo.2025.112939","url":null,"abstract":"<div><div>The evolution of the cryosphere and climate in northern Patagonia during the late Pleistocene are relatively well-known thanks to chronologies on ice-marginal features. However, this knowledge mainly represents the magnitude and duration of extreme cold intervals occurring during glacial maxima. Consequently, less is known about the state of the glaciers and climate during transitions between full glacial and interglacial stages. Given that morphometric attributes of glacial cirques are considered as robust indicators of palaeoglacial and palaeoclimate conditions during phases of minor glaciation, examining cirques will yield key insights to assess the typology of glaciers and associated climate conditions during those pivotal periods. In this study, we systematically analyzed the morphology and spatial distribution of 3081 cirques in northern Patagonia between ∼40^o and ∼ 45^o S. Our findings revealed that circular cirques, reflecting widespread long-lived small glaciers, dominate northern Patagonia. Eastward increase of cirque floor altitude from the coast to the continent along with prevailing east-to-south aspects indicate a key role of westerly-controlled climate and radiative balance in cirque development. Morphometry and spatial distribution of cirques along with statistical analyses indicate that annual total precipitation, minimum temperature, and incoming solar radiation altogether play a major role in cirque development in northern Patagonia, although the relative importance of these factors might vary spatially. Regional lithology exerts a secondary influence mostly in cirque geometry. We conclude that the most frequent state of the cryosphere within the Pleistocene glacial cycles in northern Patagonia is characterized by moderate glaciations similar to that existing during glacial terminations.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112939"},"PeriodicalIF":2.6,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869887","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":"Mechanism for the synchronous changes between lake level and global sea level during the Eocene warmhouse climate: Evidence from lacustrine carbonates","authors":"Jinghong Xu ,&nbsp;Pei Guo ,&nbsp;Yiquan Ma ,&nbsp;Chao Jiang ,&nbsp;Peng Liu ,&nbsp;Wenli Xu ,&nbsp;Changzhi Li","doi":"10.1016/j.palaeo.2025.112972","DOIUrl":"10.1016/j.palaeo.2025.112972","url":null,"abstract":"<div><div>Under the Eocene warmhouse climate, the lake level changes in lacustrine basins in East China have been found to synchronize with global sea level changes, although the mechanism driving these synchronized changes remains unclear. Here, we focus on the lacustrine carbonates of the upper fourth member of the Shahejie Formation (Es4s) in the Zhanhua Sag of the Bohai Bay Basin to study the controlling factors of the lake level changes in East China and to analyze the major cause of their linkage to global sea level changes. Based on observations of thin sections, cathodoluminescence, scanning electron microscopy and analyses of carbon and oxygen isotopes, the vertical changes of carbonate lithofacies and geochemistry over the Es4s have been reconstructed. The Es4s of the Bohai Bay Basin consists of a complete third-order sequence, with carbonate deposition changing from gypseous micritic carbonates during the lowstand stage, to dolomicrobialites and dolograinstones during the transgressive stage, to marlstone at the maximum lake flooding surface, and to micritic limestone during the highstand stage. Upward, oxygen isotopic compositions of carbonates show a negative excursion (from −7 ‰ to −11 ‰) in the transgression system tract, while carbon isotopic compositions instead show a positive excursion (from −1 ‰ to +4 ‰). The deposition of dolostone with lowest oxygen isotopes and highest carbon isotopes during the transgressive stage is interpreted to be related to the mixing of meteoric water with saline lake water. This study suggests that astronomically driving monsoon climate change is likely to be one of the reasons for the synchronized changes in lake level and global sea-level, and that other potential factors need to be further investigated.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112972"},"PeriodicalIF":2.6,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855449","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}