Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Middle Triassic humidification in Southern North China linked to northward propagation of Qinling Orogenic Belt","authors":"Wentao Yang ,&nbsp;Wenguang Tang ,&nbsp;Jianghai Yang ,&nbsp;Hongyu Zhang ,&nbsp;Yuansheng Du","doi":"10.1016/j.palaeo.2025.112948","DOIUrl":"10.1016/j.palaeo.2025.112948","url":null,"abstract":"<div><div>Orogenic uplift can change landscape topography and influence regional climatic conditions. However, it is generally hard to track the causal linkage of regional climate change with orogenesis from geological records due to lack of direct correlations between climatic and tectonic evolution. During the early-middle Triassic, there was a subarid to subhumid climate shift in Southern North China along with the formation of the Qinling Orogenic Belt. To further understand the early-middle Triassic climate shift and its potential linkage with the Qinling orogenesis, two early-middle Triassic successions through the upper Heshanggou to Ermaying formations in the Jiyuan area in Southern North China Basin were studied by sedimentology, paleosols and detrital zircon provenance analysis. The paleosols are characterized by calcareous nodule horizons and have morphological features of calcic paleosols. Based on depth to the calcareous nodule horizon of the observed paleosols, regional precipitation was estimated and showed an increase from less than 420 to more than 800 mm/yr in the lower Ermaying Formation. This climate humidification is accompanied by the fluvial to deltaic facies transition and postdates a significant provenance change recorded by the detrital zircon U<img>Pb ages. Detrital zircons from the Heshanggou Formation exhibit two primary U<img>Pb age groups of 530–380 Ma and 1100–700 Ma, indicating a dominant provenance from the North Qinling Belt. In contrast, detrital zircons from the Ermaying Formation show three major U<img>Pb age groups of 2900–2300 Ma, 2100–1650 Ma, and 330–230 Ma, pointing to a provenance from the Southern Margin of North China. This provenance shift can be interpreted as indicative of the northward propagation of the orogenic uplift. In this context of tectonic evolution, we proposed that the increased precipitation in the Southern North China was related to the orogenic uplift to the south. This study enhances our understanding of the interactions between climate and tectonics from geological record.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"669 ","pages":"Article 112948"},"PeriodicalIF":2.6,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820687","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":"Holocene coastal evolution and paleogeography of the Izumo Plain and Lake Shinji, Western Japan: Incised-valley fills in a wave-dominated estuary environment","authors":"Aan Dianto ,&nbsp;Kota Katsuki ,&nbsp;Tetsuya Sakai ,&nbsp;Koji Seto ,&nbsp;Toshimichi Nakanishi ,&nbsp;Toko Tanaka ,&nbsp;Iori Miura ,&nbsp;Akira Hayashida ,&nbsp;Toshiaki Irizuki ,&nbsp;Yoshikazu Sampei ,&nbsp;Akira Tsujimoto ,&nbsp;Masami Watanabe ,&nbsp;Takuto Ando ,&nbsp;Yasuhide Nakamura ,&nbsp;Yoshiki Saito","doi":"10.1016/j.palaeo.2025.112941","DOIUrl":"10.1016/j.palaeo.2025.112941","url":null,"abstract":"<div><div>The sedimentary infill of the Izumo Plain was studied with emphasis on the influence of coastal evolution and paleogeography. The Izumo Plain and Lake Shinji belong to Paleo-Shinji Bay, an east-west incised valley formed during the Last Glacial Maximum and drowned by the early Holocene sea-level rise. Using micro-XRF, CNS elemental analysis, grain size, diatom analysis, and robust radiocarbon dates for three newly collected cores from the plain, complemented by three previously studied cores from the plain and Lake Shinji, five depositional phases have been identified. The phases include estuarine to coastal plain (up to 9.8 cal. kyBP), transgressive central basin (9.8–7.7 cal. kyBP), regressive central basin (7.7–3.7 cal. kyBP), regressive inner central basin (3.7–0.7 cal. kyBP), and delta front (&lt;0.7 cal. kyBP). Beginning at ∼10.2 cal. kyBP, marine inundation caused by early Holocene sea-level rise shifted deposition from fluvial gravel to muddy sediment in the transgressive central basin. The high sediment accumulation during the transgression suggests that coastal erosion transported sediment into the bay. The regressive central basin, driven by decelerated sea-level rise, is characterized by thinly laminated muddy sediments deposited at a lower accumulation rate due to the shallowness of the bay mouth and the topography of the depression, resulting in anoxic conditions. Northward progradation of a bay-side delta began at ∼6.5 cal. kyBP, eventually dividing the regressive central basin into western and eastern basins by ∼3.7 cal. kyBP, with the eastern inner basin evolving into a more enclosed environment. By 0.7 cal. kyBP, intensified bay-side delta expansion, caused by a change in the main river channel, partially filled the eastern inner basin and formed the Izumo Plain. However, the unfilled estuary, now known as Lake Shinji, remained in a coastal lake. The infill history of Paleo-Shinji Bay was characterized by rapid marine sediment accumulation during the early Holocene sea-level rise, followed by bay-side delta progradation during the later Holocene under relatively stable to falling sea levels, providing insights into the evolution of estuarine infill in wave-dominated systems.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112941"},"PeriodicalIF":2.6,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839342","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":"Li/Ca of modern brachiopods: A potential paleoseawater thermometer","authors":"Uwe Brand ,&nbsp;Claire Rollion-Bard ,&nbsp;Karem Azmy ,&nbsp;M. Aleksandra Bitner ,&nbsp;Alan Logan ,&nbsp;Erika Griesshaber ,&nbsp;Maria Simonet Roda ,&nbsp;Wolfgang W. Schmahl ,&nbsp;Sandra Gordillo ,&nbsp;Nima Vaez-zadeh Asadi ,&nbsp;Elizabeth Harper ,&nbsp;Audrey K. Morrison","doi":"10.1016/j.palaeo.2025.112928","DOIUrl":"10.1016/j.palaeo.2025.112928","url":null,"abstract":"<div><div>Lithium in marine carbonates may hold key information about their temperature of formation and thus of the thermal history of ambient seawater. Here, we present Li/Ca, Mg/Ca, and Sr/Ca results of modern rhynchonelliformean brachiopods from high to low latitudes, shallow to deep and warm to cold seas covering the world's oceans.</div><div>Craniids as a group incorporate Li into their shell at a faster rate than any other brachiopod group, and due to their paucity will not be considered contributing material. The primary layer calcite of rhynchonelliformean brachiopods, due to the highly variable nature of its Li content, is deemed unsuitable as a proxy. In contrast, the Li/Ca ratios of fibers of the secondary layer within Terebratulida and Rhynchonellida, in conjunction with the innermost calcite of the Thecideida, appear to be free of major influence by growth rate, water depth, seawater pH and salinity. We compiled Li/Ca thermometers based on: 1) second-layer fiber-calcite Li results [2LB, N_G = 57], and 2) with additional Li/Ca results of thecideide calcite [2LBT, N_G = 60]. The proposed Li/Ca-brachiopod seawater thermometers (linear 1 and 2), which are independent of seawater chemistry, are as follows:</div><div>T°C = 32.85 (±0.52) – 0.670 (±0.014) Li/Ca_2LB (μmol/mol) r² = 0.978<!--> <!-->(1)</div><div>T°C = 34.73 (±0.37) – 0.716 (±0.010) Li/Ca_2LBT (μmol/mol) r² = 0.987<!--> <!-->(2)</div><div>Brachiopods are important biocalcifiers especially during the Paleozoic, and thus, the proposed Li/Ca thermometer may be an invaluable supplementary tool to the oxygen and clumped isotope thermometers in characterizing its seawater and climate history.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"669 ","pages":"Article 112928"},"PeriodicalIF":2.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817540","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":"Detrital zircon evidence for the evolution of the Paleo-Asian Ocean and Pangea scenarios during late Paleozoic times","authors":"Zeyu Wang ,&nbsp;Fuxiang Li ,&nbsp;Qiang Ren ,&nbsp;Shi Sun ,&nbsp;Jian Luo ,&nbsp;Anqing Chen","doi":"10.1016/j.palaeo.2025.112925","DOIUrl":"10.1016/j.palaeo.2025.112925","url":null,"abstract":"<div><div>The Central Asian Orogenic Belt (CAOB) is one of the Earth's largest and longest-lived accretionary orogenic collages, consisting of numerous accretionary prisms, magmatic arcs, ophiolites and microcontinents. The Solonker and Hegenshan suture zones in the eastern CAOB record the Late Paleozoic closure of the Paleo-Asian Ocean; however, closure times and variability remain uncertain, and there are ongoing disputes about how East Asian blocks linked with the Pangea supercontinent. In this paper, we report detrital zircon U-Pb ages and trace elements from the eastern CAOB, which indicate that the Northern Orogenic Belt received sediment from the Uliastai active continental margin of the Mongolia Block during Pennsylvanian times. In Early to Middle Permian times, the Northern Orogenic Belt exhibited an internal detrital source with a single age cluster, demonstrating its isolation on both north and south sides, flanked by the Solonker and Hegenshan oceans. However, from Late Permian to Early Triassic times, the sediments of the Northern Orogenic Belt along with adjacent areas displayed a mixed exotic provenance derived from both the North China Block and Mongolia Block, providing evidence for the simultaneous closure of both the Solonker and Hegenshan oceans. The source-to-sink system during the assembly of the Mongolia Block and North China Block further demonstrates a weak connection to the Laurussia supercontinent. These findings highlight the global tectonic evolution from Pangea B to A during the Late Paleozoic.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"669 ","pages":"Article 112925"},"PeriodicalIF":2.6,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143799265","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":"Changes in the relationship between temperature and precipitation during the Holocene recorded by the sediments of Yangying Co, eastern Tibetan Plateau","authors":"Peiyao Xu,&nbsp;Duo Wu,&nbsp;Qili Xiao,&nbsp;Tao Wang,&nbsp;Shilong Guo,&nbsp;Jinghua Huang,&nbsp;Lili Pan,&nbsp;Mengjing Li","doi":"10.1016/j.palaeo.2025.112937","DOIUrl":"10.1016/j.palaeo.2025.112937","url":null,"abstract":"<div><div>The Indian summer monsoon (ISM) is an important component of the Asian monsoon system. It transports moisture and heat from the ocean to mid- and low-latitude regions, which influence their climate and ecology. Under the influence of the Asian summer monsoon, temperature and precipitation in East Asia vary synchronously on the seasonal scale; however, this relationship was decoupled on the decadal scale over the past century, and on millennial or even longer time scales. In the context of the “Holocene temperature conundrum” and seasonal temperature reconstructions, the relationship between temperature and precipitation variations in the ISM region during the Holocene has been found to be increasingly complex. This study focuses on Yangying Co on Haizi Mountain, on the southeastern Tibetan Plateau. We obtained a high-quality, 475-cm-long, continuous sediment core (Yangying Co 2022B) from the lake center, which was dated using analyses of ¹³⁷Cs, ²¹⁰Pb, and AMS ¹⁴C. After evaluating the carbon reservoir effect, a reliable chronology was established for this core since 15 ka (1 ka = 1000 years). Sedimentological proxies (grain size) and geochemical proxies (XRF elements, TOC, TN, organic matter content) were used to reconstruct the history of glacier activity during the last deglaciation, and temperature and precipitation changes during the Holocene. The changes in TOC, TN, organic matter content, and Br (reflecting biomass variations) reveal a gradual increase in biomass in the Yangying Co region during the early Holocene, which reached a maximum during the middle Holocene and then decreased. The biomass is primarily controlled by summer temperature changes, and our Holocene summer temperature record shows a warming–thermal maximum–cooling temporal pattern. The gradual decrease in PC1 of scanning XRF data and in mean grain size during the Holocene indicate a weakening of the ISM. Influenced by cloud cover, dust flux, volcanic activity, and snow/ice albedo, the precipitation and summer temperature in the ISM region of the Tibetan Plateau were decoupled during the early Holocene (11.6–6 cal kyr BP). However, after ∼6 cal kyr BP, both precipitation and summer temperature decreased, possibly influenced by the decreasing Northern Hemisphere summer insolation. Our findings contribute to an improved understanding of current and future regional and global climate changes.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"669 ","pages":"Article 112937"},"PeriodicalIF":2.6,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817539","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":"Paleoceanographic condition changes in the Eastern Bransfield Basin, Antarctic Peninsula, since the late glacial interval and its implications","authors":"Sunghan Kim ,&nbsp;Young-Suk Bak ,&nbsp;Kyu-Cheul Yoo ,&nbsp;Min Kyung Lee ,&nbsp;Jae Il Lee ,&nbsp;Sookwan Kim ,&nbsp;Jinku Park ,&nbsp;So-Young Kim ,&nbsp;Heung Soo Moon ,&nbsp;Myung-Il Kang ,&nbsp;Hyo Jin Kim","doi":"10.1016/j.palaeo.2025.112934","DOIUrl":"10.1016/j.palaeo.2025.112934","url":null,"abstract":"<div><div>Antarctic Peninsula is the most northerly area in the Antarctica, thus it is vulnerable to warming climate. Although it is well known that relatively warm water mass input onto the Antarctic shelf region facilitates ice shelf retreat, when and how the water mass exchange between the deep Southern Ocean and the Antarctic shelf regions is not well known in ice proximal areas due to sea ice dynamics on the continental shelf region. Here, we document the diatom assemblage record of a sediment core with high sedimentation rates since the late glacial interval from 34.6 ka to address surface environmental changes in the Eastern Bransfield Basin (EBB). We found that the EBB was covered by extensive sea ice showing millennial-scale variations during the late glacial interval. The sea ice started to decrease during the deglacial interval (19–11 ka) with slight increases of open ocean influence. In addition, meltwater input was significant during 14.7–11.3 ka which corresponds to Antarctic Ice Sheet Discharge events reported in the Scotia Sea including Meltwater pulse 1A and 1B. During the Holocene after 9 ka, relatively warm water mass input distinctively increased into the EBB contemporaneous with a remarkable decrease in sea ice influence indicating the strong relationship between sea ice and warm water mass input. In addition, meltwater input at 9 ka was also distinctive in the EBB, but there was no corresponding Antarctic Ice Sheet Discharge event in the Scotia Sea. Our results show how well surface environmental changes in the EBB correspond to the global climate change and the regional climatic characteristics at the same time.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"669 ","pages":"Article 112934"},"PeriodicalIF":2.6,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820686","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":"Extreme flood events on Western Sakhalin and their linkage to cyclogenesis activity in the western North Pacific in middle-late Holocene","authors":"N.G. Razjigaeva ,&nbsp;L.A. Ganzey ,&nbsp;T.A. Grebennikova ,&nbsp;V.I. Ponomarev ,&nbsp;V.V. Afanasiev ,&nbsp;A.O. Gorbunov ,&nbsp;M.A. Klimin","doi":"10.1016/j.palaeo.2025.112933","DOIUrl":"10.1016/j.palaeo.2025.112933","url":null,"abstract":"<div><div>This study provides insights into the natural variability of flood events in the past and the role of large-scale atmospheric circulation patterns in shaping flood patterns. The geological record of extreme floods associated with the passage of the strongest typhoons and deep extratropical cyclones over the past 6370 years has been reconstructed in Western Sakhalin (the Yablochnaya River Basin). A section of peat bog with numerous loam layers formed during extreme floods was used for the reconstruction. A recent analog of such events is typhoon Phyllis (1981 CE), which produced up to 300 mm of rainfall. The analysis of ash content (i.e., non-organic content) in peat, combined with the age-depth model, allows for identifying of 38 past flood events and periods of weaker floods when organomineral sediments accumulated. During active cyclogenesis periods, extreme floods were frequent once every 10–30 years. The analysis of paleoclimatic conditions provides insights into the climate factors contributing to flood risk. Long-term periods with extreme floods were identified as 6470–5490, 4300–3670 yr BP according to the age-depth model. During the last 3110 years, severe floods were rare events. We compare the records of strong floods from the western and eastern coasts of South Sakhalin and different East Asian regions. Periods with frequent strong paleotyphoons and deep extratropical cyclones show different temporal variations in the regions, which could be due to variance cyclone trajectories determined by the anomalies of baric fields. Intensification of the warm Kuroshio Current, which plays a major role in meridional heat and moisture transport, was also a driver of cyclogenesis activation and extreme flooding in southern Sakhalin Island. At present, the increase in the intensity of cyclogenesis and the frequency of typhoons in the middle-late Holocene was closely related to the western Pacific warm pool in the western equatorial Pacific, manifestation of El Niño and anomalies of atmospheric centers of action. This information enhances our understanding of flood history and provides valuable insights for flood risk assessment and climate change adaptation strategies.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"669 ","pages":"Article 112933"},"PeriodicalIF":2.6,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808661","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":"Improving the temporal resolution of middle Eocene–late Oligocene foraminiferal biomagneto-chronology: Insights from CONOP and chronologic significance of biotic events","authors":"Zhengbo Lu ,&nbsp;Junxuan Fan ,&nbsp;Bridget S. Wade ,&nbsp;James Ogg ,&nbsp;Laia Alegret ,&nbsp;Peter M. Sadler ,&nbsp;Michael H. Stephenson ,&nbsp;Yukun Shi ,&nbsp;Chao Qian ,&nbsp;Ke Xue ,&nbsp;Peiyue Fang","doi":"10.1016/j.palaeo.2025.112929","DOIUrl":"10.1016/j.palaeo.2025.112929","url":null,"abstract":"<div><div>To understand Earth's history, a comprehensive time scale integrating available stratigraphic information is crucial. The middle Eocene to late Oligocene offers abundant stratigraphic information, including foraminiferal and magnetostratigraphic data. However, traditional biostratigraphy uses only a small fraction (1–10 %) of foraminifera as markers, reducing the time scale's temporal resolution and lacking a quantitative method to assess the chronologic significance of both mearker and non-marker biotic events. This study employs the quantitative stratigraphic method, Constrained Optimization (CONOP), using 11 reference sections to create a high-resolution magneto-foraminiferal time scale for the middle Eocene–late Oligocene. The new composite sequence improves temporal resolution by nearly tenfold over traditional methods, incorporating 409 additional biotic events while aligning closely with established markers. Two evaluation factors, diachrony and centrality, were developed to assess the temporal consistency of events among different locations and geographic ranges. Findings reveal that the chronological significance of small benthic foraminifera, planktonic foraminifera, and foraminiferal zonal species events increases sequentially. Conversely, larger benthic foraminiferal events are affected by endemism, complicating their evaluation. Incorporating magnetostratigraphic data into CONOP enhances the robustness and accuracy of stratigraphic correlation. Our approach offers a way to apply CONOP for high-resolution time scales, allowing for a comprehensive assessment of biotic events beyond the use of zonal fossils.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"669 ","pages":"Article 112929"},"PeriodicalIF":2.6,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786223","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":"Quantifying the equatorial climate shifts in the Indo-Burma range using late Eocene–early Oligocene leaf fossils","authors":"Harshita Bhatia ,&nbsp;Kapesa Lokho ,&nbsp;Gaurav Srivastava ,&nbsp;O. Chonchibeni Ezung","doi":"10.1016/j.palaeo.2025.112931","DOIUrl":"10.1016/j.palaeo.2025.112931","url":null,"abstract":"<div><div>The late Eocene–early Oligocene geological time span saw significant Antarctic glaciation, which played a crucial role in shaping global climate patterns and influencing regional climates and ocean circulation changes. In this study, we quantitatively reconstructed the climate of a low latitude site using fossil leaf morphological traits recovered from the Laisong Formation (late Eocene–early Oligocene) of the Indo-Burma range. The Climate Leaf Analysis Multivariate Program was used to quantify the climate, suggesting a mean annual temperature of 25.3 ± 2.3 °C and a cold month mean temperature of 19.2 ± 3.5 °C. The length of the growing season extended throughout the year, with a mean annual precipitation of 244.2 ± 64.3 cm, showing clear rainfall seasonality between rainy summers (130 ± 40 cm) and dry winters (21.7 ± 9.8 cm). The study further reveals that high rainfall in the low latitude region resulted from the northward migration of the intertropical convergence zone due to Antarctic glaciation.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"669 ","pages":"Article 112931"},"PeriodicalIF":2.6,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783230","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":"Dental microwear of bovids from the Pliocene-Pleistocene transition in the lower Awash Valley, Ethiopia","authors":"A.G. Kirkpatrick ,&nbsp;I.A. Lazagabaster ,&nbsp;J.R. Robinson ,&nbsp;J. Rowan ,&nbsp;C.J. Campisano ,&nbsp;K.E. Reed ,&nbsp;J.R. Scott ,&nbsp;P.S. Ungar","doi":"10.1016/j.palaeo.2025.112932","DOIUrl":"10.1016/j.palaeo.2025.112932","url":null,"abstract":"<div><div>Ethiopian fossil sites in the Lee Adoyta basin at Ledi-Geraru and the Maka'amitalu basin at Hadar straddle the Pliocene-Pleistocene transition and have both yielded fossil hominins attributed to early <em>Homo</em>. Faunal remains at these sites hold potential for providing insights into the ecological backdrop of the transition between these epochs in the lower Awash Valley and, by extension, the environments associated with the first appearance of <em>Homo</em> in the fossil record. Herbivore guild composition, ecomorphological study, and isotope analyses suggest that compared with paleoenvironments at earlier sites in the lower Awash, those in the Lee Adoyta basin and at Maka'amitalu had higher abundances of tropical grasses and sedges relative to browse plants. Here we bring another proxy to bear on the environments of the Lee Adoyta basin and Maka'amitalu associated with early <em>Homo</em>, dental microwear texture analysis. Dental microwear has been shown to separate grazing from browsing bovids and, because food choice reflects availability, can by extension provide insights into habitat. We employ texture analysis to infer the diets of bovid individuals from the Lee Adoyta basin (<em>n</em> = 13) and Maka'amitalu (<em>n</em> = 6) that preserve antemortem microwear. High-resolution replicas were scanned with a white-light confocal profiler and texture complexity and anisotropy were calculated for each surface and compared with baseline data for an extant sample of grazers, browsers, and mixed feeders. Values for bovids from the two sites do not differ from one another. Both samples have high anisotropy and low complexity, suggesting a graze-dominated diet and wide availability of grasses at both sites. These results are consistent with conclusions derived from other proxies.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112932"},"PeriodicalIF":2.6,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835149","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}