Pub Date : 2026-01-18DOI: 10.1016/j.palaeo.2026.113571
Nanze Liang , Yibing Li , Yan Li , Haifeng Wang , Hongjun Yu , Xingyong Xu , Qiao Su , Xingyu Jiang , Guangquan Chen , Tengfei Fu , Weiwei Chen , Liang Yi
The Bohai Sea, located on the northern continent of the East China Sea, is highly sensitive to sea-level fluctuations, monsoon variability, and tectonic activity; however, its timing, extent, and environmental responses during the early–middle Pleistocene remain unclear. To reconstruct its environmental evolution during about 0.8–1.0 Ma, we analyzed magnetic, geochemical, and color reflectance properties of core Lz908 in the south Bohai Sea and revealed a distinct environmental shift at ∼925 ka. Regional comparisons of marine-influenced stratigraphy indicate that this shift possibly represents a long-standing lake system gradually replaced by transgressive conditions, which coincides with the subsidence of the Miaodao uplift, suggesting that seawater occupied the Bohai basin. Environmental proxies derived from magnetic and elemental properties were dominated by 40 ka and 22 ka cycles, highlighting orbital influences on regional sedimentary processes. Integrating these results, we proposed that a distinct transition occurred around 925 ka and environmental processes during this key interval were likely modulated by East Asian monsoon and sea-level fluctuations.
{"title":"Monsoon and sea-level induced environmental shifts in the Bohai Sea, East Asia during the early-middle Pleistocene","authors":"Nanze Liang , Yibing Li , Yan Li , Haifeng Wang , Hongjun Yu , Xingyong Xu , Qiao Su , Xingyu Jiang , Guangquan Chen , Tengfei Fu , Weiwei Chen , Liang Yi","doi":"10.1016/j.palaeo.2026.113571","DOIUrl":"10.1016/j.palaeo.2026.113571","url":null,"abstract":"<div><div>The Bohai Sea, located on the northern continent of the East China Sea, is highly sensitive to sea-level fluctuations, monsoon variability, and tectonic activity; however, its timing, extent, and environmental responses during the early–middle Pleistocene remain unclear. To reconstruct its environmental evolution during about 0.8–1.0 Ma, we analyzed magnetic, geochemical, and color reflectance properties of core Lz908 in the south Bohai Sea and revealed a distinct environmental shift at ∼925 ka. Regional comparisons of marine-influenced stratigraphy indicate that this shift possibly represents a long-standing lake system gradually replaced by transgressive conditions, which coincides with the subsidence of the Miaodao uplift, suggesting that seawater occupied the Bohai basin. Environmental proxies derived from magnetic and elemental properties were dominated by 40 ka and 22 ka cycles, highlighting orbital influences on regional sedimentary processes. Integrating these results, we proposed that a distinct transition occurred around 925 ka and environmental processes during this key interval were likely modulated by East Asian monsoon and sea-level fluctuations.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113571"},"PeriodicalIF":2.7,"publicationDate":"2026-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146015899","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}
Pub Date : 2026-01-17DOI: 10.1016/j.palaeo.2026.113572
Feng Shi , Xibin Tan , Yijia Ye , Qiaoqiao Guo , Shuang Bian
The Red River Fault (RRF), an important block-boundary fault at the southeastern margin of the Tibetan Plateau, experienced a reversal in strike-slip direction in the late Cenozoic. The Ailao Shan is a mountain belt located parallel to the RRF on its southwestern side. The topographic analysis at the Ailao Shan may provide constraints for the kinematic reversal of the RRF and associated landform evolution. In this study, we analyze the drainage-divide stability at the Ailao Shan using χ-plot method. The results show that most segments of the Ailao Shan drainage divide are moving northeastwards (towards the RRF). This drainage-divide migration could be driven by differential uplift, dextral strike-slip faulting on the RRF, and/or the loss of drainage area of the Red River. To further constrain the vertical tectonic activity of the RRF, we analyzed channel steepness of rivers at the Ailao Shan based on the DEM. The results imply that the western segment of the RRF has normal fault activity, while the eastern segment does not. Overall, the results of topographic analysis at the Ailao Shan, including drainage-divide stability and the channel steepness index, jointly support that the RRF is a dextral strike-slip fault, with normal faulting component at its western segment. This study reveals that the landform of the Ailao Shan has not yet reached a steady state after the kinematic reversal of the RRF, and implies that the kinematic reversal might be a relatively young event.
{"title":"The Ailao Shan drainage divide is migrating northeastwards in response to the late Cenozoic kinematic reversal of the Red River Fault, southeastern margin of the Tibetan Plateau","authors":"Feng Shi , Xibin Tan , Yijia Ye , Qiaoqiao Guo , Shuang Bian","doi":"10.1016/j.palaeo.2026.113572","DOIUrl":"10.1016/j.palaeo.2026.113572","url":null,"abstract":"<div><div>The Red River Fault (RRF), an important block-boundary fault at the southeastern margin of the Tibetan Plateau, experienced a reversal in strike-slip direction in the late Cenozoic. The Ailao Shan is a mountain belt located parallel to the RRF on its southwestern side. The topographic analysis at the Ailao Shan may provide constraints for the kinematic reversal of the RRF and associated landform evolution. In this study, we analyze the drainage-divide stability at the Ailao Shan using χ-plot method. The results show that most segments of the Ailao Shan drainage divide are moving northeastwards (towards the RRF). This drainage-divide migration could be driven by differential uplift, dextral strike-slip faulting on the RRF, and/or the loss of drainage area of the Red River. To further constrain the vertical tectonic activity of the RRF, we analyzed channel steepness of rivers at the Ailao Shan based on the DEM. The results imply that the western segment of the RRF has normal fault activity, while the eastern segment does not. Overall, the results of topographic analysis at the Ailao Shan, including drainage-divide stability and the channel steepness index, jointly support that the RRF is a dextral strike-slip fault, with normal faulting component at its western segment. This study reveals that the landform of the Ailao Shan has not yet reached a steady state after the kinematic reversal of the RRF, and implies that the kinematic reversal might be a relatively young event.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"686 ","pages":"Article 113572"},"PeriodicalIF":2.7,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038986","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}
Pub Date : 2026-01-17DOI: 10.1016/j.palaeo.2026.113576
Ji Young Shin , Min Kyung Lee , Yongjae Yu , Sun Ki Choi , Jong Kuk Hong , Moon Son , Young Ji Joo
Sedimentary archives along the Ross Sea margin provide key insights into the interactions among Antarctic ice dynamics, bottom water formation, and depositional processes near the marine-based ice sheet. Here, we integrate sedimentological, geochemical, and magnetic records from a continental rise sediment core to reveal the late Pleistocene redox evolution and develop a refined age framework. A distinct redox transition is identified across the mid- to late Brunhes period, from reducing conditions—indicated by debilitated paleomagnetic signals, magnetite dissolution, and manganese depletion—to a more oxic interval enriched in maghemite and manganese-bearing phases. Sedimentary features straddling this boundary capture a shift from an ice-proximal deposition with reworked shelf materials to an ice-distal regime characterized by enhanced marine organic matter degradation and improved bottom water oxygenation. Combined relative paleointensity and lithostratigraphic alignments provide feasible chronological constraints for the last 400 kyr, although the iron reducing interval warrants careful consideration. The resulting chronology places the major stratigraphic and redox reorganization at ∼250 ka, coincident with the extensive Ross Sea ice retreat. These multi-proxy observations demonstrate that reductive magnetite loss during ice sheet expansions can substantially modify magnetic records near the Antarctic ice margin. Nevertheless, integrated sedimentary magnetic proxies remain effective tools for both developing age models and reconstructing past redox and cryosphere–ocean variability.
{"title":"Redox-driven diagenetic impacts on sedimentary and magnetic records during late Pleistocene oceanographic evolution on the Ross Sea continental margin","authors":"Ji Young Shin , Min Kyung Lee , Yongjae Yu , Sun Ki Choi , Jong Kuk Hong , Moon Son , Young Ji Joo","doi":"10.1016/j.palaeo.2026.113576","DOIUrl":"10.1016/j.palaeo.2026.113576","url":null,"abstract":"<div><div>Sedimentary archives along the Ross Sea margin provide key insights into the interactions among Antarctic ice dynamics, bottom water formation, and depositional processes near the marine-based ice sheet. Here, we integrate sedimentological, geochemical, and magnetic records from a continental rise sediment core to reveal the late Pleistocene redox evolution and develop a refined age framework. A distinct redox transition is identified across the mid- to late Brunhes period, from reducing conditions—indicated by debilitated paleomagnetic signals, magnetite dissolution, and manganese depletion—to a more oxic interval enriched in maghemite and manganese-bearing phases. Sedimentary features straddling this boundary capture a shift from an ice-proximal deposition with reworked shelf materials to an ice-distal regime characterized by enhanced marine organic matter degradation and improved bottom water oxygenation. Combined relative paleointensity and lithostratigraphic alignments provide feasible chronological constraints for the last 400 kyr, although the iron reducing interval warrants careful consideration. The resulting chronology places the major stratigraphic and redox reorganization at ∼250 ka, coincident with the extensive Ross Sea ice retreat. These multi-proxy observations demonstrate that reductive magnetite loss during ice sheet expansions can substantially modify magnetic records near the Antarctic ice margin. Nevertheless, integrated sedimentary magnetic proxies remain effective tools for both developing age models and reconstructing past redox and cryosphere–ocean variability.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"686 ","pages":"Article 113576"},"PeriodicalIF":2.7,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038980","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}
Pub Date : 2026-01-17DOI: 10.1016/j.palaeo.2026.113575
Eduardo S. Bellosi , Claudia del Río , John McArthur , Ian L. Millar
Among the Cenozoic marine incursions in southern South America, the Chattian-Langhian Patagoniense episode is particularly significant due to its extensive spatial distribution, abundant fossil record, and comprehensive research history. It flooded several Atlantic basins, between S 40o - 53o, each with different tectonic context and infill history. In this work we present new geochronologic, stratigraphic, sedimentologic and paleontological data of the Patagoniense successions to evaluate basin evolution, sedimentation and their molluskan faunas; and to establish the regional architecture based on new correlations. The results confirm that the Patagoniense consisted of three separated transgressive episodes: Juliense, Leonense and Superpatagoniense, whose ages are here determined using Sr-isotope stratigraphy. Although largely overlooked before now as a separate transgression, we demonstrate that the Superpatagoniense interval is clearly distinguishable as a unique transgression, with an extensive record in basins of central and northern Patagonia between 15.9 and 15.0 Ma. The biostratigraphic reappraisal of the Patagoniense Molluskan Assemblages indicates that the youngest (NVG) fauna is preserved in the uppermost Leonense and Superpatagoniense beds, and can be calibrated between 17.0 and 15.0 Ma. This fauna was dominated by tropical genera, and ranged up to S 47o during the Miocene Climatic Optimum, whilst also showing latitudinal changes in composition that are related to temperature. The three transgressions and the subsequent regressions exhibit a staggered pattern, being younger northwards. Such large-scale, orderly architecture would have responded to the independent or combined effects of several geological and climatic factors, but to date, none of them can be clearly established. They were not uniform or instantaneous, but rather propagated over ten million years across the marginal southeastern Atlantic basins. This tiered pattern suggests a common link between processes that controlled the transgressions, which must be considered in future works.
{"title":"Evolution of staggered Oligocene-Miocene transgressions and molluskan faunas in eastern Patagonian basins","authors":"Eduardo S. Bellosi , Claudia del Río , John McArthur , Ian L. Millar","doi":"10.1016/j.palaeo.2026.113575","DOIUrl":"10.1016/j.palaeo.2026.113575","url":null,"abstract":"<div><div>Among the Cenozoic marine incursions in southern South America, the Chattian-Langhian <em>Patagoniense</em> episode is particularly significant due to its extensive spatial distribution, abundant fossil record, and comprehensive research history. It flooded several Atlantic basins, between S 40<sup>o</sup> - 53<sup>o</sup>, each with different tectonic context and infill history. In this work we present new geochronologic, stratigraphic, sedimentologic and paleontological data of the <em>Patagoniense</em> successions to evaluate basin evolution, sedimentation and their molluskan faunas; and to establish the regional architecture based on new correlations. The results confirm that the <em>Patagoniense</em> consisted of three separated transgressive episodes: <em>Juliense</em>, <em>Leonense</em> and <em>Superpatagoniense</em>, whose ages are here determined using Sr-isotope stratigraphy. Although largely overlooked before now as a separate transgression, we demonstrate that the <em>Superpatagoniense</em> interval is clearly distinguishable as a unique transgression, with an extensive record in basins of central and northern Patagonia between 15.9 and 15.0 Ma. The biostratigraphic reappraisal of the <em>Patagoniense</em> Molluskan Assemblages indicates that the youngest (NVG) fauna is preserved in the uppermost <em>Leonense</em> and <em>Superpatagoniense</em> beds, and can be calibrated between 17.0 and 15.0 Ma. This fauna was dominated by tropical genera, and ranged up to S 47<sup>o</sup> during the Miocene Climatic Optimum, whilst also showing latitudinal changes in composition that are related to temperature. The three transgressions and the subsequent regressions exhibit a staggered pattern, being younger northwards. Such large-scale, orderly architecture would have responded to the independent or combined effects of several geological and climatic factors, but to date, none of them can be clearly established. They were not uniform or instantaneous, but rather propagated over ten million years across the marginal southeastern Atlantic basins. This tiered pattern suggests a common link between processes that controlled the transgressions, which must be considered in future works.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"686 ","pages":"Article 113575"},"PeriodicalIF":2.7,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038984","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}
Pub Date : 2026-01-17DOI: 10.1016/j.palaeo.2026.113579
I.T. Lawson , C.M. Åkesson , G.C. Dargie , J. del Aguila Pasquel , F.C. Draper , A. Hastie , T.J. Kelly , D. Sassoon , V. Abraham , T.R. Baker , D. Fabel , P. Gulliver , E.N. Honorio Coronado , K.H. Roucoux
Peatlands accumulate and store carbon over centuries to tens of millennia. Analysing the age structure of peatlands helps us to understand their genesis, development, and stability as carbon stores, and informs peatland management. Here we analyse new and previously published radiocarbon dates from peatlands in the Pastaza-Marañón Basin in Peru, the largest known peatland complex in Amazonia. We show that peatlands here are younger (< c. 8900 and frequently <2500 years old) than in many other parts of the tropics. Basal peat ages in extant peatlands vary depending on the geomorphological stability of the landscape, with younger basal dates typically occurring close to active river floodplains and older basal dates in more stable contexts. The data indicate that within individual peatlands, peat initiation may occur synchronously across a basin, or peat may spread laterally from one or more nucleation sites. Only two out of seven well-dated records show clear hiatuses in past peat accumulation, suggesting that carbon sequestration in some, but not all peatlands has been vulnerable to landscape hydrological change or climate change. Peatland ecosystems in the region are economically important sources of non-timber forest products, which it may be possible to harvest sustainably without biomass loss or drainage, but our analysis indicates that the peat itself accumulates too slowly to be considered as a renewable resource on economically meaningful timescales.
{"title":"Holocene patterns of peat accumulation in Peruvian Amazonia","authors":"I.T. Lawson , C.M. Åkesson , G.C. Dargie , J. del Aguila Pasquel , F.C. Draper , A. Hastie , T.J. Kelly , D. Sassoon , V. Abraham , T.R. Baker , D. Fabel , P. Gulliver , E.N. Honorio Coronado , K.H. Roucoux","doi":"10.1016/j.palaeo.2026.113579","DOIUrl":"10.1016/j.palaeo.2026.113579","url":null,"abstract":"<div><div>Peatlands accumulate and store carbon over centuries to tens of millennia. Analysing the age structure of peatlands helps us to understand their genesis, development, and stability as carbon stores, and informs peatland management. Here we analyse new and previously published radiocarbon dates from peatlands in the Pastaza-Marañón Basin in Peru, the largest known peatland complex in Amazonia. We show that peatlands here are younger (< c. 8900 and frequently <2500 years old) than in many other parts of the tropics. Basal peat ages in extant peatlands vary depending on the geomorphological stability of the landscape, with younger basal dates typically occurring close to active river floodplains and older basal dates in more stable contexts. The data indicate that within individual peatlands, peat initiation may occur synchronously across a basin, or peat may spread laterally from one or more nucleation sites. Only two out of seven well-dated records show clear hiatuses in past peat accumulation, suggesting that carbon sequestration in some, but not all peatlands has been vulnerable to landscape hydrological change or climate change. Peatland ecosystems in the region are economically important sources of non-timber forest products, which it may be possible to harvest sustainably without biomass loss or drainage, but our analysis indicates that the peat itself accumulates too slowly to be considered as a renewable resource on economically meaningful timescales.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"686 ","pages":"Article 113579"},"PeriodicalIF":2.7,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038983","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}
Pub Date : 2026-01-16DOI: 10.1016/j.palaeo.2026.113574
Ennie Schulze , Frank Riedel , Ulrich Struck
Continental palaeoclimate archives in subseasonal resolution remain limited in Europe, restricting insights into short-term environmental variability. This study investigates the freshwater gastropod Viviparus hellenicus as a potential high-resolution climate archive, using specimens from six habitats in Lake Trichonida, Greece, a large, deep lake in a semi-arid Mediterranean setting. Stable isotope patterns across shell ontogeny reveal sinusoidal δ18O patterns indicative of annual cycles, with minimal seasonal bias and strong correlation to water temperature. These trends suggest that evaporation exerts limited isotopic influence in well-buffered, deep limnic systems despite semi-arid climatic conditions. In contrast, shells from a nearby shallow, transitional site show greater sensitivity to shifting water sources and evaporative enrichment of the lake water, underscoring the role of local hydrology in shaping isotopic signals. While the shells reliably record seasonal interannual temperature variability, observed δ18O offsets and intraspecific variability complicate absolute temperature reconstructions. These uncertainties are likely to be amplified in fossil assemblages. Overall, Viviparus shells are considered promising high-resolution archives of continental climate, provided that local ecological and hydrological contexts are carefully considered.
{"title":"Exploring the potential of Viviparus shells (Gastropoda) for palaeoclimate reconstructions: A sclerochronological stable isotope case study from Lake Trichonida, Greece","authors":"Ennie Schulze , Frank Riedel , Ulrich Struck","doi":"10.1016/j.palaeo.2026.113574","DOIUrl":"10.1016/j.palaeo.2026.113574","url":null,"abstract":"<div><div>Continental palaeoclimate archives in subseasonal resolution remain limited in Europe, restricting insights into short-term environmental variability. This study investigates the freshwater gastropod <em>Viviparus hellenicus</em> as a potential high-resolution climate archive, using specimens from six habitats in Lake Trichonida, Greece, a large, deep lake in a semi-arid Mediterranean setting. Stable isotope patterns across shell ontogeny reveal sinusoidal δ<sup>18</sup>O patterns indicative of annual cycles, with minimal seasonal bias and strong correlation to water temperature. These trends suggest that evaporation exerts limited isotopic influence in well-buffered, deep limnic systems despite semi-arid climatic conditions. In contrast, shells from a nearby shallow, transitional site show greater sensitivity to shifting water sources and evaporative enrichment of the lake water, underscoring the role of local hydrology in shaping isotopic signals. While the shells reliably record seasonal interannual temperature variability, observed δ<sup>18</sup>O offsets and intraspecific variability complicate absolute temperature reconstructions. These uncertainties are likely to be amplified in fossil assemblages. Overall, <em>Viviparus</em> shells are considered promising high-resolution archives of continental climate, provided that local ecological and hydrological contexts are carefully considered.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"687 ","pages":"Article 113574"},"PeriodicalIF":2.7,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080708","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}
Pub Date : 2026-01-16DOI: 10.1016/j.palaeo.2026.113565
Xiao-Hua Shao , Xiao-Hong Zhao , Peng-Fa Li , Kan Zhao , Xing-Gong Kong , Yong-Jin Wang , Hai Cheng
The 8.2 ka event represents a critical benchmark for understanding abrupt climate variability, yet prominent stalagmite records (DA and D4) from southwestern China display notable discrepancies, underscoring the need for new, precisely dated reconstructions to clarify regional monsoon responses. Here we present a high-resolution speleothem δ18O and δ13C record (SH) from Shuanghe Cave, southwestern China, with ∼2-year sampling resolution and a chronological uncertainty of ≤40 years, which captures detailed variability in the East Asian summer monsoon (EASM) during the 8.2 ka event. The SH δ18O record reveals a pronounced weak-monsoon signal with a characteristic double-plunging structure, terminating at 8070 ± 40 yr BP, consistent within dating uncertainties with Greenland ice cores and other high resolution monsoon stalagmite δ18O records. Simulated June–August wind anomalies from the TraCE model further corroborate a substantial reduction in EASM intensity during this interval. Moreover, the SH δ18O and δ13C records, together with other multi-proxy stalagmite data, indicate a largely synchronous hydroclimatic response from the northern to southern Chinese monsoon domain, characterized by a coherent shift toward drier conditions during the 8.2 ka event. When considered alongside Greenland ice-core evidence, these results highlight a strong North Atlantic–East Asian teleconnection, supporting the interpretation that abrupt North Atlantic cooling—caused by a slowdown of the Atlantic Meridional Overturning Circulation (AMOC)—shifted the Intertropical Convergence Zone (ITCZ) southward, thereby weakening the East Asian summer monsoon (EASM) and resulting in diminished rainfall across the Chinese monsoon domain.
{"title":"High-resolution stalagmite records from Southwest China reveal a North Atlantic link to the 8.2 ka event","authors":"Xiao-Hua Shao , Xiao-Hong Zhao , Peng-Fa Li , Kan Zhao , Xing-Gong Kong , Yong-Jin Wang , Hai Cheng","doi":"10.1016/j.palaeo.2026.113565","DOIUrl":"10.1016/j.palaeo.2026.113565","url":null,"abstract":"<div><div>The 8.2 ka event represents a critical benchmark for understanding abrupt climate variability, yet prominent stalagmite records (DA and D4) from southwestern China display notable discrepancies, underscoring the need for new, precisely dated reconstructions to clarify regional monsoon responses. Here we present a high-resolution speleothem δ<sup>18</sup>O and δ<sup>13</sup>C record (SH) from Shuanghe Cave, southwestern China, with ∼2-year sampling resolution and a chronological uncertainty of ≤40 years, which captures detailed variability in the East Asian summer monsoon (EASM) during the 8.2 ka event. The SH δ<sup>18</sup>O record reveals a pronounced weak-monsoon signal with a characteristic double-plunging structure, terminating at 8070 ± 40 yr BP, consistent within dating uncertainties with Greenland ice cores and other high resolution monsoon stalagmite δ<sup>18</sup>O records. Simulated June–August wind anomalies from the TraCE model further corroborate a substantial reduction in EASM intensity during this interval. Moreover, the SH δ<sup>18</sup>O and δ<sup>13</sup>C records, together with other multi-proxy stalagmite data, indicate a largely synchronous hydroclimatic response from the northern to southern Chinese monsoon domain, characterized by a coherent shift toward drier conditions during the 8.2 ka event. When considered alongside Greenland ice-core evidence, these results highlight a strong North Atlantic–East Asian teleconnection, supporting the interpretation that abrupt North Atlantic cooling—caused by a slowdown of the Atlantic Meridional Overturning Circulation (AMOC)—shifted the Intertropical Convergence Zone (ITCZ) southward, thereby weakening the East Asian summer monsoon (EASM) and resulting in diminished rainfall across the Chinese monsoon domain.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"686 ","pages":"Article 113565"},"PeriodicalIF":2.7,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038981","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}
Pub Date : 2026-01-14DOI: 10.1016/j.palaeo.2026.113568
Poonam Chahal , Rupa Ghosh , Debarati Nag , Anil Kumar , Yogesh Ray , Pradeep Srivastava
<div><div>The Himalaya and its foreland, a thrust fold belt, is one of the most geomorphically dynamic and populous regions on Earth. The tectonic forces and climate driven surface processes persistently shape the landscape of the region. The river systems draining through this mountain range actively respond to neotectonic deformation and climatic changes, recording the long-term history of mountain building and erosion. In this paper, we review the chronologically constrained fluvial archives such as river fills, strath terraces, and alluvial fans from the Indus, Ganga, Gandaki, and Brahmaputra systems. Together, these rivers capture the full range of climatic and tectonic conditions across the Himalaya. Building on these studies, we propose an integrated view of how climate and tectonics have jointly influenced the region’s landscape evolution.</div><div>Aggradation and incision in these rivers are controlled by the balance between sediment supply and stream power, which are linked to the changes in monsoon intensity and tectonic uplift. Chronological data reveal three main aggradational phases in the Indus (49–39, 30–20, and 13–5 ka) and Ganga (46–36, 29–23, and 16–8 ka), and two in the eastern Himalaya (32–22, and 18–8 ka), corresponding to glacial–interglacial transitions. Periods of climatic recovery from cold–dry to warm–humid conditions favored valley filling and fan formation, while strong monsoon phases triggered river incision and terrace development. Extreme monsoon-driven floods during 39-31ka and 13-5 ka left widespread sedimentary imprints across the mountain belt.</div><div>Fluvial archives across the Himalaya–Ganga Plain system shows a time-lagged response of 3–4 ka between incision in the mountains and in the foreland. The pattern reflects tight coupling between tectonic deformation and climate-driven erosion.</div><div>Neotectonic deformation in the NW Himalaya is expressed through active nature of south-vergent frontal thrusts and north-vergent backthrusts, forming a bivergent wedge. Rivers in this region record deformation in the form of strath terraces, which reflect alternating phases of uplift, incision, and stability, with incision rates ranging from ∼1 to 15 mm/yr with highest rates near the Himalayan Frontal Thrust. Spatial variations in the bedrock uplift and erosion reveal strong tectono-geomorphic coupling—rapid deformation at the frontal wedge, out-of-sequence uplift in the Lesser Himalaya, and active extensional faulting in the Tethyan sector. Together, these features demonstrate that the Himalaya is a critically tapered, asymmetric bivergent wedge, where both frontal thrusting and hinterland faulting actively shape uplift, erosion, and landscape evolution.</div><div>The Ganga foreland basin also remains tectonically active, influenced by Himalayan thrusting, reactivated basement faults, and flexural movements along the peripheral bulge. These forces have shaped its river systems, sedimentation, and characteristic
{"title":"Rivers of Himalaya: Response to climate and tectonic variables","authors":"Poonam Chahal , Rupa Ghosh , Debarati Nag , Anil Kumar , Yogesh Ray , Pradeep Srivastava","doi":"10.1016/j.palaeo.2026.113568","DOIUrl":"10.1016/j.palaeo.2026.113568","url":null,"abstract":"<div><div>The Himalaya and its foreland, a thrust fold belt, is one of the most geomorphically dynamic and populous regions on Earth. The tectonic forces and climate driven surface processes persistently shape the landscape of the region. The river systems draining through this mountain range actively respond to neotectonic deformation and climatic changes, recording the long-term history of mountain building and erosion. In this paper, we review the chronologically constrained fluvial archives such as river fills, strath terraces, and alluvial fans from the Indus, Ganga, Gandaki, and Brahmaputra systems. Together, these rivers capture the full range of climatic and tectonic conditions across the Himalaya. Building on these studies, we propose an integrated view of how climate and tectonics have jointly influenced the region’s landscape evolution.</div><div>Aggradation and incision in these rivers are controlled by the balance between sediment supply and stream power, which are linked to the changes in monsoon intensity and tectonic uplift. Chronological data reveal three main aggradational phases in the Indus (49–39, 30–20, and 13–5 ka) and Ganga (46–36, 29–23, and 16–8 ka), and two in the eastern Himalaya (32–22, and 18–8 ka), corresponding to glacial–interglacial transitions. Periods of climatic recovery from cold–dry to warm–humid conditions favored valley filling and fan formation, while strong monsoon phases triggered river incision and terrace development. Extreme monsoon-driven floods during 39-31ka and 13-5 ka left widespread sedimentary imprints across the mountain belt.</div><div>Fluvial archives across the Himalaya–Ganga Plain system shows a time-lagged response of 3–4 ka between incision in the mountains and in the foreland. The pattern reflects tight coupling between tectonic deformation and climate-driven erosion.</div><div>Neotectonic deformation in the NW Himalaya is expressed through active nature of south-vergent frontal thrusts and north-vergent backthrusts, forming a bivergent wedge. Rivers in this region record deformation in the form of strath terraces, which reflect alternating phases of uplift, incision, and stability, with incision rates ranging from ∼1 to 15 mm/yr with highest rates near the Himalayan Frontal Thrust. Spatial variations in the bedrock uplift and erosion reveal strong tectono-geomorphic coupling—rapid deformation at the frontal wedge, out-of-sequence uplift in the Lesser Himalaya, and active extensional faulting in the Tethyan sector. Together, these features demonstrate that the Himalaya is a critically tapered, asymmetric bivergent wedge, where both frontal thrusting and hinterland faulting actively shape uplift, erosion, and landscape evolution.</div><div>The Ganga foreland basin also remains tectonically active, influenced by Himalayan thrusting, reactivated basement faults, and flexural movements along the peripheral bulge. These forces have shaped its river systems, sedimentation, and characteristic","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"686 ","pages":"Article 113568"},"PeriodicalIF":2.7,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980561","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}
Pub Date : 2026-01-12DOI: 10.1016/j.palaeo.2026.113555
Koji Seike , Thomas S.N. Oliver
The trace fossil Skolithos is a simple, sub-vertical, unbranched, cylindrical burrow that characterizes the trace fossil from early Cambrian to recent times. The Skolithos ichnofacies is an indicator of high-energy coastal marine facies, such as the sandy beaches of wave-dominated coasts; however, to date, neoichnological studies have only reported its occurrence in low-energy settings, where it is produced by a variety of annelids, phoronids, and priapulids. In this paper, we describe the burrow produced by the Australian giant beach worm (Australonuphis, family Onuphidae) at Bengello Beach, southeastern Australia, where they occur in a high-energy, wave-dominated sandy coastal setting. The burrows of this omnivorous scavenger show a straight or slightly bent vertical shaft without branching or chambers, and may be regarded as a modern analog of the trace fossil Skolithos. The burrows are distributed only below the lower foreshore, and therefore we infer that the uppermost level of Skolithos occurrences in the Phanerozoic fossil record may be a useful indicator of ancient sea-level in the Skolithos ichnofacies. As such, our findings improve knowledge of the palaeoecology of the Skolithos ichnofacies, including feeding ecology, and enhance its palaeoenvironmental utility.
{"title":"Burrows of the giant beach worm (Australonuphis) in a high-energy beach environment in New South Wales, Australia: implications for the palaeoecology of some Phanerozoic Skolithos assemblages","authors":"Koji Seike , Thomas S.N. Oliver","doi":"10.1016/j.palaeo.2026.113555","DOIUrl":"10.1016/j.palaeo.2026.113555","url":null,"abstract":"<div><div>The trace fossil <em>Skolithos</em> is a simple, sub-vertical, unbranched, cylindrical burrow that characterizes the trace fossil from early Cambrian to recent times. The <em>Skolithos</em> ichnofacies is an indicator of high-energy coastal marine facies, such as the sandy beaches of wave-dominated coasts; however, to date, neoichnological studies have only reported its occurrence in low-energy settings, where it is produced by a variety of annelids, phoronids, and priapulids. In this paper, we describe the burrow produced by the Australian giant beach worm (<em>Australonuphis</em>, family Onuphidae) at Bengello Beach, southeastern Australia, where they occur in a high-energy, wave-dominated sandy coastal setting. The burrows of this omnivorous scavenger show a straight or slightly bent vertical shaft without branching or chambers, and may be regarded as a modern analog of the trace fossil <em>Skolithos.</em> The burrows are distributed only below the lower foreshore, and therefore we infer that the uppermost level of <em>Skolithos</em> occurrences in the Phanerozoic fossil record may be a useful indicator of ancient sea-level in the <em>Skolithos</em> ichnofacies. As such, our findings improve knowledge of the palaeoecology of the <em>Skolithos</em> ichnofacies, including feeding ecology, and enhance its palaeoenvironmental utility.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"686 ","pages":"Article 113555"},"PeriodicalIF":2.7,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981304","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}
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