Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

HORSE: Harmonize regional and global stratigraphic records through horizon sequencing

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-21 DOI: 10.1016/j.palaeo.2025.112976

Tianyi Chu , Hanhui Huang , Junxuan Fan , Yiying Deng , Tao Xu , Chao Qian , Ke Xue , H. David Sheets , Michael H. Stephenson , Yukun Shi , Xudong Hou

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.

{"title":"HORSE: Harmonize regional and global stratigraphic records through horizon sequencing","authors":"Tianyi Chu , Hanhui Huang , Junxuan Fan , Yiying Deng , Tao Xu , Chao Qian , Ke Xue , H. David Sheets , Michael H. Stephenson , Yukun Shi , 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}

引用次数: 0

Palaeoglacial and palaeoclimate inferences from cirque morphometry and spatial distribution across northern Patagonia (40o – 45o S)

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-19 DOI: 10.1016/j.palaeo.2025.112939

R.L. Soteres , D.A. Cabrera , M.A. Martini , E.A. Sagredo , J. Pedraza , R.M. Carrasco , M.R. Kaplan , J.M. Araos

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.

{"title":"Palaeoglacial and palaeoclimate inferences from cirque morphometry and spatial distribution across northern Patagonia (40o – 45o S)","authors":"R.L. Soteres , D.A. Cabrera , M.A. Martini , E.A. Sagredo , J. Pedraza , R.M. Carrasco , M.R. Kaplan , 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<sup>o</sup> and ∼ 45<sup>o</sup> 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}

引用次数: 0

Mechanism for the synchronous changes between lake level and global sea level during the Eocene warmhouse climate: Evidence from lacustrine carbonates

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-18 DOI: 10.1016/j.palaeo.2025.112972

Jinghong Xu , Pei Guo , Yiquan Ma , Chao Jiang , Peng Liu , Wenli Xu , Changzhi Li

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.

在始新世暖温带气候条件下，华东地区湖泊盆地的湖泊水位变化与全球海平面变化同步，但这种同步变化的驱动机制尚不清楚。在此，我们以渤海湾盆地沾化沙河街地层（Es4s）上第四系湖相碳酸盐岩为研究对象，探讨华东地区湖泊水位变化的控制因素，并分析其与全球海平面变化联系的主要原因。根据薄片观察、阴极发光、扫描电镜和碳氧同位素分析，重建了Es4s上碳酸盐岩相和地球化学的垂直变化。渤海湾盆地的Es4s由一个完整的三阶序列组成，碳酸盐沉积从低海拔阶段的石膏质微晶碳酸盐岩，到横断阶段的白云岩和独流成岩，再到最大湖泊洪积面的泥灰岩，以及高海拔阶段的微晶灰岩。向上看，碳酸盐的氧同位素组成在横断系统道呈负偏移（从-7‰到-11‰），而碳同位素组成则呈正偏移（从-1‰到+4‰）。在横断阶段，氧同位素最低而碳同位素最高的白云石的沉积被解释为与陨石水与盐湖水的混合有关。这项研究表明，天文驱动的季风气候变化很可能是湖泊水位与全球海平面同步变化的原因之一，其他潜在因素还需要进一步研究。

{"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 , Pei Guo , Yiquan Ma , Chao Jiang , Peng Liu , Wenli Xu , 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}

引用次数: 0

Influence of monsoon variability on hydrographic and productivity dynamics in the western Bay of Bengal during the late Holocene: A planktic foraminiferal perspective

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-18 DOI: 10.1016/j.palaeo.2025.112971

Satabdi Mohanty , Swagata Chaudhuri , Koustav Chattopadhyay , Nitika Millicent Patrick , Nishant Vats , Ajoy K. Bhaumik

Late Holocene paleoceanographic changes and the paleoenvironmental evolution of the Western Bay of Bengal (WBoB) were reconstructed using planktic foraminifera obtained from the NGHP-15A core sediments. The planktic foraminiferal record shows significant variations in surface hydrography and productivity due to seasonal monsoon rainfall and wind strength during the late Holocene. The foraminiferal records combined with several paleoceanographic indices provide insights into the centennial scale hydrographic and trophic level evolution and ecosystem dynamics of WBoB. Our findings demonstrate four different regimes of monsoon-induced fluctuations in the upper water column structure and productivity changes during the Roman Warm Period (RWP), Dark Age Cold Period (DACP), Medieval Climate Anomaly (MCA), and Medieval Climate Anomaly-Little Ice Age (MCA-LIA) transition. We concluded that oligotrophic conditions along with stratified upper water column prevailed during RWP and MCA due to intensified southwest monsoon and related river discharge. Enhanced eutrophication during the DACP and MCA-LIA transition, associated with the significant upward movement of nutrient-rich subsurface water to the photic zone caused by the strengthened Northeast (NE) monsoon winds. Overall, our findings indicate that the ocean surface hydrographic structure and productivity dynamics in the WBoB were modulated by the concurrent phases of enhanced precipitation during the SW monsoon and dry reverse wind circulation during the NE monsoon respectively.

{"title":"Influence of monsoon variability on hydrographic and productivity dynamics in the western Bay of Bengal during the late Holocene: A planktic foraminiferal perspective","authors":"Satabdi Mohanty , Swagata Chaudhuri , Koustav Chattopadhyay , Nitika Millicent Patrick , Nishant Vats , Ajoy K. Bhaumik","doi":"10.1016/j.palaeo.2025.112971","DOIUrl":"10.1016/j.palaeo.2025.112971","url":null,"abstract":"<div><div>Late Holocene paleoceanographic changes and the paleoenvironmental evolution of the Western Bay of Bengal (WBoB) were reconstructed using planktic foraminifera obtained from the NGHP-15A core sediments. The planktic foraminiferal record shows significant variations in surface hydrography and productivity due to seasonal monsoon rainfall and wind strength during the late Holocene. The foraminiferal records combined with several paleoceanographic indices provide insights into the centennial scale hydrographic and trophic level evolution and ecosystem dynamics of WBoB. Our findings demonstrate four different regimes of monsoon-induced fluctuations in the upper water column structure and productivity changes during the Roman Warm Period (RWP), Dark Age Cold Period (DACP), Medieval Climate Anomaly (MCA), and Medieval Climate Anomaly-Little Ice Age (MCA-LIA) transition. We concluded that oligotrophic conditions along with stratified upper water column prevailed during RWP and MCA due to intensified southwest monsoon and related river discharge. Enhanced eutrophication during the DACP and MCA-LIA transition, associated with the significant upward movement of nutrient-rich subsurface water to the photic zone caused by the strengthened Northeast (NE) monsoon winds. Overall, our findings indicate that the ocean surface hydrographic structure and productivity dynamics in the WBoB were modulated by the concurrent phases of enhanced precipitation during the SW monsoon and dry reverse wind circulation during the NE monsoon respectively.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112971"},"PeriodicalIF":2.6,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874551","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}

引用次数: 0

Organic matter sources and productivity variations in the southeastern Bay of Bengal in the past 54,000 years

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-17 DOI: 10.1016/j.palaeo.2025.112970

Maria C. Fernandes , Tyson Sebastian , Sunil Vadakkepuliyambatta , Pratheeksha Nayak , Madhusudan G. Yadava , Palayil John Kurian

Primary productivity in the Bay of Bengal (BoB) has been primarily controlled by salinity stratification driven by the Indian summer monsoon (ISM). The increase in freshwater influx during enhanced ISM periods results in strong salinity stratification, which inhibits the vertical mixing of nutrients and limits primary production. The southern BoB receives relatively less freshwater influx compared to the northern BoB. However, very few studies have been carried out concerning productivity variation in the southern BoB. Hence, to understand the organic matter sources and productivity variation, a sediment core (MGS 22/01) collected from southeastern BoB was analysed for total organic carbon (TOC), total nitrogen (TN), and stable isotopes (δ¹³C, δ¹⁵N), Calcium Carbonate (CaCO₃), Barium (Ba), and for paleoredox condition, Manganese (Mn)/Aluminum (Al) proxy was used. Results indicated relatively more terrestrial-derived organic matter (OM) during ∼54 cal ka BP up to 15 cal ka BP and relatively low input after ∼15 cal ka BP, controlled by sea level and ISM. Low TOC and high Mn/Al indicated prevailing oxic conditions during ∼12 to 6 cal ka BP. High marine productivity was observed during the early MIS 3, LGM, and the mid-late Holocene period. Strong ISM resulted in weaker marine productivity, and weak ISM enhanced marine productivity in the present study area.

{"title":"Organic matter sources and productivity variations in the southeastern Bay of Bengal in the past 54,000 years","authors":"Maria C. Fernandes , Tyson Sebastian , Sunil Vadakkepuliyambatta , Pratheeksha Nayak , Madhusudan G. Yadava , Palayil John Kurian","doi":"10.1016/j.palaeo.2025.112970","DOIUrl":"10.1016/j.palaeo.2025.112970","url":null,"abstract":"<div><div>Primary productivity in the Bay of Bengal (BoB) has been primarily controlled by salinity stratification driven by the Indian summer monsoon (ISM). The increase in freshwater influx during enhanced ISM periods results in strong salinity stratification, which inhibits the vertical mixing of nutrients and limits primary production. The southern BoB receives relatively less freshwater influx compared to the northern BoB. However, very few studies have been carried out concerning productivity variation in the southern BoB. Hence, to understand the organic matter sources and productivity variation, a sediment core (MGS 22/01) collected from southeastern BoB was analysed for total organic carbon (TOC), total nitrogen (TN), and stable isotopes (δ<sup>13</sup>C, δ<sup>15</sup>N), Calcium Carbonate (CaCO<sub>3</sub>), Barium (Ba), and for paleoredox condition, Manganese (Mn)/Aluminum (Al) proxy was used. Results indicated relatively more terrestrial-derived organic matter (OM) during ∼54 cal ka BP up to 15 cal ka BP and relatively low input after ∼15 cal ka BP, controlled by sea level and ISM. Low TOC and high Mn/Al indicated prevailing oxic conditions during ∼12 to 6 cal ka BP. High marine productivity was observed during the early MIS 3, LGM, and the mid-late Holocene period. Strong ISM resulted in weaker marine productivity, and weak ISM enhanced marine productivity in the present study area.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112970"},"PeriodicalIF":2.6,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870347","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}

引用次数: 0

Paleoceanographic changes along the western Spitsbergen margin, evidence from planktic microfossil during the last 10 kyr BP

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-17 DOI: 10.1016/j.palaeo.2025.112940

Fiorenza Torricella , Caterina Morigi , Viviana Gamboa-Sojo , Katia Carbonara , Laura Bronzo , Renata G. Lucchi

Marine microfossils record oceanographic changes that are closely linked to climate variability. We use diatoms, planktic foraminifera, and calcareous nannofossils to reconstruct the paleoceanographic evolution along the western margin of Spitsbergen (Arctic) during the last 10 kyr BP. The data are compared with other records from the western margin of Spitsbergen. We recognize three distinct units corresponding to the late phase of the early Holocene, the middle Holocene, and the late Holocene.

The results indicate warm sea surface conditions along the western margin of Spitsbergen from 10 to 7.5 kyr BP, simultaneous to a maximum of summer insolation. Maximum advection of North Atlantic Water (NAW) occurs between 10 and 9 kyr BP, corresponding to the last part of the Holocene Thermal Maximum (HTM).

The microfossil association evidenced a gradual cooling of the surface water between 7.4 and 3.8 kyr BP. Surface cooling can be explained by increased water mass exchange with the Arctic Ocean and/or reduced solar insolation. From 3.8 kyr BP, we have evidence of strong seasonality, stratified surface waters, and a slight inflow of NAW. The last 2000 years are characterized by an alternation of warm and cold periods associated with a change in NAW inflow.

海洋微化石记录了与气候变异密切相关的海洋变化。我们利用硅藻、浮游有孔虫和钙质化石重建了斯匹次卑尔根（北极）西缘在公元前 10 千年的古海洋演变。这些数据与斯匹次卑尔根西缘的其他记录进行了比较。结果表明，在公元前 10 千年至公元前 7.5 千年期间，斯匹次卑尔根西缘海面温暖，同时夏季日照达到最高值。北大西洋水（NAW）的最大吸力出现在公元前 10 至 9 千年之间，与全新世热极盛期（HTM）的最后一部分相对应。微化石关联证明，在公元前 7.4 至 3.8 千年之间，表层海水逐渐冷却。表层冷却的原因是与北冰洋的水量交换增加和/或太阳日照减少。从公元前 3.8 千年起，我们有证据表明表层海水具有强烈的季节性和分层性，并有少量的北冰洋海水流入。在过去的 2000 年中，暖期和冷期交替出现，这与 NAW 流入量的变化有关。

{"title":"Paleoceanographic changes along the western Spitsbergen margin, evidence from planktic microfossil during the last 10 kyr BP","authors":"Fiorenza Torricella , Caterina Morigi , Viviana Gamboa-Sojo , Katia Carbonara , Laura Bronzo , Renata G. Lucchi","doi":"10.1016/j.palaeo.2025.112940","DOIUrl":"10.1016/j.palaeo.2025.112940","url":null,"abstract":"<div><div>Marine microfossils record oceanographic changes that are closely linked to climate variability. We use diatoms, planktic foraminifera, and calcareous nannofossils to reconstruct the paleoceanographic evolution along the western margin of Spitsbergen (Arctic) during the last 10 kyr BP. The data are compared with other records from the western margin of Spitsbergen. We recognize three distinct units corresponding to the late phase of the early Holocene, the middle Holocene, and the late Holocene.</div><div>The results indicate warm sea surface conditions along the western margin of Spitsbergen from 10 to 7.5 kyr BP, simultaneous to a maximum of summer insolation. Maximum advection of North Atlantic Water (NAW) occurs between 10 and 9 kyr BP, corresponding to the last part of the Holocene Thermal Maximum (HTM).</div><div>The microfossil association evidenced a gradual cooling of the surface water between 7.4 and 3.8 kyr BP. Surface cooling can be explained by increased water mass exchange with the Arctic Ocean and/or reduced solar insolation. From 3.8 kyr BP, we have evidence of strong seasonality, stratified surface waters, and a slight inflow of NAW. The last 2000 years are characterized by an alternation of warm and cold periods associated with a change in NAW inflow.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112940"},"PeriodicalIF":2.6,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850341","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}

引用次数: 0

Dust supply to the West Philippine Sea since the Middle Pleistocene and distinct influences of the Westerlies after the Mid-Brunhes Event

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-16 DOI: 10.1016/j.palaeo.2025.112961

Yun Cai , Dong Xu , Haifeng Wang , Yanping Chen , Haiyan Jin , Yibing Li , Weiwei Chen , Liang Yi

One of the long-standing debates focuses on whether iron (Fe) fertilization enhanced ocean productivity and fueled the biological carbon pump, contributing to glacial CO₂ drawdown. To date, dust flux has been a primary focus, while two other factors, namely dust source and transportation, are generally ignored. In this study, we report high-resolution dust records retrieved from rare earth element variabilities of a sediment core in the West Philippine Sea and discuss the potential linkage between our dust records and driving forces over the last 900 ka. We find an anti-phase relationship between the Ce-based dust record and the Ba-based productivity, both of which are characterized by three astronomical rhythms. By comparing our dust records with various wind proxies, we find that dust input in the study area is closely related to changes in the Westerlies and the East Asian Winter Monsoon, and the Westerlies became the dominant factor after the Mid-Brunhes Event (MBE). Along with the local minimum of obliquity, changes in dust input and ocean productivity are synchronously intensified during the post-MEB glacial periods. Together with comparisons to dust source changes in the inner Asia, we speculate that the strengthening and southward migration of the Westerlies may strengthen the influence of dust sources on marine productivity.

{"title":"Dust supply to the West Philippine Sea since the Middle Pleistocene and distinct influences of the Westerlies after the Mid-Brunhes Event","authors":"Yun Cai , Dong Xu , Haifeng Wang , Yanping Chen , Haiyan Jin , Yibing Li , Weiwei Chen , Liang Yi","doi":"10.1016/j.palaeo.2025.112961","DOIUrl":"10.1016/j.palaeo.2025.112961","url":null,"abstract":"<div><div>One of the long-standing debates focuses on whether iron (Fe) fertilization enhanced ocean productivity and fueled the biological carbon pump, contributing to glacial CO<sub>2</sub> drawdown. To date, dust flux has been a primary focus, while two other factors, namely dust source and transportation, are generally ignored. In this study, we report high-resolution dust records retrieved from rare earth element variabilities of a sediment core in the West Philippine Sea and discuss the potential linkage between our dust records and driving forces over the last 900 ka. We find an anti-phase relationship between the Ce-based dust record and the Ba-based productivity, both of which are characterized by three astronomical rhythms. By comparing our dust records with various wind proxies, we find that dust input in the study area is closely related to changes in the Westerlies and the East Asian Winter Monsoon, and the Westerlies became the dominant factor after the Mid-Brunhes Event (MBE). Along with the local minimum of obliquity, changes in dust input and ocean productivity are synchronously intensified during the post-MEB glacial periods. Together with comparisons to dust source changes in the inner Asia, we speculate that the strengthening and southward migration of the Westerlies may strengthen the influence of dust sources on marine productivity.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112961"},"PeriodicalIF":2.6,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852000","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}

引用次数: 0

Paleoenvironmental evolution during the early Eocene climate optimum in a mid–high-latitude lake–marsh system, NE Asia

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-15 DOI: 10.1016/j.palaeo.2025.112960

Penglin Zhang , Qingtao Meng , Fei Hu , Lin Ma , Jinguo Li

The Early Eocene Climatic Optimum (EECO) represents a pinnacle of long-term global warming and is considered an analog for potential ecological impacts in a future high-CO₂ world (atmospheric pCO₂ > 500 ppmv). Recent work from mid- to high-latitude lake–marsh systems in the Northern Hemisphere suggests that the EECO was characterized by a decoupled response in terrestrial and marine deposition, indicating that previous ecological models obtained from Ocean Drilling Program sites may not adequately explain the dynamics of the land–ocean ecological balance during the EECO. Here, new insights involving magnetic mineralogy, high-resolution dynamic sedimentary noise analysis, stable isotope examination, X-ray diffraction, and elemental investigations from the Dalianhe section in NE Asia, which record minimal organic δ¹³C values, sulfate reduction index values, limited C/N ratios, and relatively high dynamic noise orbital tuning lake levels of the EECO in lake–marsh systems at 53.1 ± 9.0°N. Moreover, lake–marsh systems at mid-high latitudes exhibit significantly greater temperature and precipitation shifts than do midlatitude marine systems, with the onset of a warming event (∼52.2 Ma) occurring after marine deposition. These analyses revealed that oceanic ventilation/mixing and East Asian monsoon responses were key drivers of the land–ocean ecological balance during the EECO. These global ecological dynamics demonstrate the sensitivity of terrestrial ecosystems and the lag of warming in response to extreme thermal events, which further constrains potential causal mechanisms for the EECO to multiple systems and highlights the importance of biogeochemical models for understanding global warming.

{"title":"Paleoenvironmental evolution during the early Eocene climate optimum in a mid–high-latitude lake–marsh system, NE Asia","authors":"Penglin Zhang , Qingtao Meng , Fei Hu , Lin Ma , Jinguo Li","doi":"10.1016/j.palaeo.2025.112960","DOIUrl":"10.1016/j.palaeo.2025.112960","url":null,"abstract":"<div><div>The Early Eocene Climatic Optimum (EECO) represents a pinnacle of long-term global warming and is considered an analog for potential ecological impacts in a future high-CO<sub>2</sub> world (atmospheric <em>p</em>CO<sub>2</sub> > 500 ppmv). Recent work from mid- to high-latitude lake–marsh systems in the Northern Hemisphere suggests that the EECO was characterized by a decoupled response in terrestrial and marine deposition, indicating that previous ecological models obtained from Ocean Drilling Program sites may not adequately explain the dynamics of the land–ocean ecological balance during the EECO. Here, new insights involving magnetic mineralogy, high-resolution dynamic sedimentary noise analysis, stable isotope examination, X-ray diffraction, and elemental investigations from the Dalianhe section in NE Asia, which record minimal organic δ<sup>13</sup>C values, sulfate reduction index values, limited C/N ratios, and relatively high dynamic noise orbital tuning lake levels of the EECO in lake–marsh systems at 53.1 ± 9.0°N. Moreover, lake–marsh systems at mid-high latitudes exhibit significantly greater temperature and precipitation shifts than do midlatitude marine systems, with the onset of a warming event (∼52.2 Ma) occurring after marine deposition. These analyses revealed that oceanic ventilation/mixing and East Asian monsoon responses were key drivers of the land–ocean ecological balance during the EECO. These global ecological dynamics demonstrate the sensitivity of terrestrial ecosystems and the lag of warming in response to extreme thermal events, which further constrains potential causal mechanisms for the EECO to multiple systems and highlights the importance of biogeochemical models for understanding global warming.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112960"},"PeriodicalIF":2.6,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859186","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}

引用次数: 0

New Miaolingian tubicolous fossils from North China and the persistence of the Ediacaran “worm-world”

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-15 DOI: 10.1016/j.palaeo.2025.112959

Yuze Wang , Michael Steiner , Pingli Wang , Xiaoyu Yang , Renchao Yang

The oldest undisputed metazoan body fossils are often represented by tubular remains, which led to the characterization of early ecosystems as the Ediacaran ‘worm-world’ fauna. Tubular body fossils continued to dominate during the Cambrian Bioradiation Event, primarily as three-dimensionally preserved small skeletal fossils, although their preservation varied widely. Most tubular fossils, however, lack soft tissue preservation, making it challenging to determine their biological affinities based solely on tube morphology. Here we describe well-preserved tubular fossils, Longgangia bilamellata gen. et sp. nov. and Selkirkia cf. columbia, from the Cambrian Mantou Formation (Miaolingian Series, Wuliuan Stage) in Burgess Shale-type preservation. Longgangia bilamellata gen. et sp. nov. features a double-layered tube wall, transversal annulations, and Y-shaped branching of half-ring annulations. The new species shows importance because of its resemblance in construction and preservation with Ediacaran tubular fossils, such as Sinospongia, Sinotubulites, and Sabellidites, therefore providing evidence for the persistence of the tube-dwelling lifestyle from the Ediacaran to the Cambrian (Miaolingian). This also highlights the evolutionary and ecological significance of tube-forming organisms during the Cambrian Bioradiation Event, an interval characterized by explosive metazoan diversification, biomineralization, genetic innovation, and niche specialization. The potential affinity with cnidarians, annelids, and hemichordates is discussed and an assignment of Longgangia gen. nov. to Annelida is considered most plausible. The new material also reveals that annelids are capable to create tubes by half-ring construction with Y-branchings of growth lines, thus emphasizing this tube construction is not exclusive to hemichordate pterobranchs.

{"title":"New Miaolingian tubicolous fossils from North China and the persistence of the Ediacaran “worm-world”","authors":"Yuze Wang , Michael Steiner , Pingli Wang , Xiaoyu Yang , Renchao Yang","doi":"10.1016/j.palaeo.2025.112959","DOIUrl":"10.1016/j.palaeo.2025.112959","url":null,"abstract":"<div><div>The oldest undisputed metazoan body fossils are often represented by tubular remains, which led to the characterization of early ecosystems as the Ediacaran ‘worm-world’ fauna. Tubular body fossils continued to dominate during the Cambrian Bioradiation Event, primarily as three-dimensionally preserved small skeletal fossils, although their preservation varied widely. Most tubular fossils, however, lack soft tissue preservation, making it challenging to determine their biological affinities based solely on tube morphology. Here we describe well-preserved tubular fossils, <em>Longgangia bilamellata</em> gen. et sp. nov. and <em>Selkirkia</em> cf. <em>columbia</em>, from the Cambrian Mantou Formation (Miaolingian Series, Wuliuan Stage) in Burgess Shale-type preservation. <em>Longgangia bilamellata</em> gen. et sp. nov. features a double-layered tube wall, transversal annulations, and Y-shaped branching of half-ring annulations. The new species shows importance because of its resemblance in construction and preservation with Ediacaran tubular fossils, such as <em>Sinospongia</em>, <em>Sinotubulites</em>, and <em>Sabellidites</em>, therefore providing evidence for the persistence of the tube-dwelling lifestyle from the Ediacaran to the Cambrian (Miaolingian). This also highlights the evolutionary and ecological significance of tube-forming organisms during the Cambrian Bioradiation Event, an interval characterized by explosive metazoan diversification, biomineralization, genetic innovation, and niche specialization. The potential affinity with cnidarians, annelids, and hemichordates is discussed and an assignment of <em>Longgangia</em> gen. nov. to Annelida is considered most plausible. The new material also reveals that annelids are capable to create tubes by half-ring construction with Y-branchings of growth lines, thus emphasizing this tube construction is not exclusive to hemichordate pterobranchs.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112959"},"PeriodicalIF":2.6,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847374","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}

引用次数: 0

Evidence for elevated wildfire activity during Cretaceous OAE 2 from eastern Tethys

IF 2.6 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Palaeogeography, Palaeoclimatology, Palaeoecology

Pub Date : 2025-04-15 DOI: 10.1016/j.palaeo.2025.112936

Shuai Shi , Xi Chen , Huifang Guo , Hanwei Yao , Kaibo Han , David B. Kemp , Shengbao Shi , Zhong Han , Chengshan Wang

Intensified frequency and scale of wildfires due to global warming has been increasingly recorded in recent years. Studies of wildfire activity during deep time greenhouse climate states are crucial for evaluating their likely impacts on the global environment and ecosystems in the future. Oceanic anoxic event 2 (OAE 2, ∼94 Ma), which was characterized by extremely high global temperature and a reduced equator-pole temperature gradient, could provide insights into our understanding of present-day global change processes. Here we provide data on polycyclic aromatic hydrocarbon (PAH) abundance from the Qiangdong section in the Tethyan Himalaya of southern Tibet to investigate wildfire behavior and its impact on the environment during OAE 2. Our results indicate a significant increase in the frequency of wildfires during the early part of OAE 2, followed by a rapid weakening. The change of PAH composition through OAE 2 in Qiangdong shares a similar trend to that previously found in the Western Interior Seaway (North America), indicating potentially globally elevated wildfire frequency during the early part of OAE 2. We also document a rapid increase in chemical index of alteration values in Qiangdong. These data, coupled with other proxies for weathering intensity through OAE 2, suggest that increased weathering during OAE 2 can be attributed at least in part to the effects of vegetation loss caused by wildfire. As such, we suggest that frequent wildfires during OAE 2 promoted the flux of nutrients to the oceans, thereby stimulating productivity that, in turn, increased the area of oceanic anoxia and organic carbon burial.

{"title":"Evidence for elevated wildfire activity during Cretaceous OAE 2 from eastern Tethys","authors":"Shuai Shi , Xi Chen , Huifang Guo , Hanwei Yao , Kaibo Han , David B. Kemp , Shengbao Shi , Zhong Han , Chengshan Wang","doi":"10.1016/j.palaeo.2025.112936","DOIUrl":"10.1016/j.palaeo.2025.112936","url":null,"abstract":"<div><div>Intensified frequency and scale of wildfires due to global warming has been increasingly recorded in recent years. Studies of wildfire activity during deep time greenhouse climate states are crucial for evaluating their likely impacts on the global environment and ecosystems in the future. Oceanic anoxic event 2 (OAE 2, ∼94 Ma), which was characterized by extremely high global temperature and a reduced equator-pole temperature gradient, could provide insights into our understanding of present-day global change processes. Here we provide data on polycyclic aromatic hydrocarbon (PAH) abundance from the Qiangdong section in the Tethyan Himalaya of southern Tibet to investigate wildfire behavior and its impact on the environment during OAE 2. Our results indicate a significant increase in the frequency of wildfires during the early part of OAE 2, followed by a rapid weakening. The change of PAH composition through OAE 2 in Qiangdong shares a similar trend to that previously found in the Western Interior Seaway (North America), indicating potentially globally elevated wildfire frequency during the early part of OAE 2. We also document a rapid increase in chemical index of alteration values in Qiangdong. These data, coupled with other proxies for weathering intensity through OAE 2, suggest that increased weathering during OAE 2 can be attributed at least in part to the effects of vegetation loss caused by wildfire. As such, we suggest that frequent wildfires during OAE 2 promoted the flux of nutrients to the oceans, thereby stimulating productivity that, in turn, increased the area of oceanic anoxia and organic carbon burial.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"670 ","pages":"Article 112936"},"PeriodicalIF":2.6,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828906","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}

引用次数: 0