Pub Date : 2025-12-23DOI: 10.1016/j.palaeo.2025.113520
Rita T. Melis , Margherita Mussi
The archeological site-complex of Melka Kunture, at 2000 m asl on the west side of the Main Ethiopian Rift, lies in a half-graben crossed by the upper Awash River. Sedimentation processes led to the building up of stratigraphic sequences consisting of primary volcaniclastic deposits interbedded with reworked volcaniclastics emplaced in a floodplain environment. We describe here the changing paleolandscape and the implications on hominin peopling from 2,000,000 to 600,000 years ago, using the sequence of the thoroughly investigated Gombore gully with added information from other sites of Melka Kunture. Together with archaeology and paleontology, detailed information is provided by stratigraphic sections, pollen and stable isotope analysis and by the ichnological record.
The available data show a fluvial dynamic landscape characterized by a floodplain with a meandering river, gravel lag deposits and fine-grained overbank deposits. The vegetation was of Afromontane type. A major volcano-tectonic event at 1.2 Ma blanketed the area with products which clogged the valley before the river was eventually able to resume its course. The abundant artefacts and faunal remains in the gravel deposits suggest that during the Early Pleistocene and the early Middle Pleistocene, before and after the 1.2 Ma event both Homo erectus with Oldowan and then Acheulean lithic productions, and later on H. heidelbergensis with middle Acheulean ones, repeatedly came to those well-drained spots. Single-purpose sites also exist in different environments and other ones provide evidence of hominins roaming through the plain.
{"title":"The paleolandscape of Melka Kunture (Ethiopia) at the time of the earliest human peopling","authors":"Rita T. Melis , Margherita Mussi","doi":"10.1016/j.palaeo.2025.113520","DOIUrl":"10.1016/j.palaeo.2025.113520","url":null,"abstract":"<div><div>The archeological site-complex of Melka Kunture, at 2000 m asl on the west side of the Main Ethiopian Rift, lies in a half-graben crossed by the upper Awash River. Sedimentation processes led to the building up of stratigraphic sequences consisting of primary volcaniclastic deposits interbedded with reworked volcaniclastics emplaced in a floodplain environment. We describe here the changing paleolandscape and the implications on hominin peopling from 2,000,000 to 600,000 years ago, using the sequence of the thoroughly investigated Gombore gully with added information from other sites of Melka Kunture. Together with archaeology and paleontology, detailed information is provided by stratigraphic sections, pollen and stable isotope analysis and by the ichnological record.</div><div>The available data show a fluvial dynamic landscape characterized by a floodplain with a meandering river, gravel lag deposits and fine-grained overbank deposits. The vegetation was of Afromontane type. A major volcano-tectonic event at 1.2 Ma blanketed the area with products which clogged the valley before the river was eventually able to resume its course. The abundant artefacts and faunal remains in the gravel deposits suggest that during the Early Pleistocene and the early Middle Pleistocene, before and after the 1.2 Ma event both <em>Homo erectus</em> with Oldowan and then Acheulean lithic productions, and later on <em>H. heidelbergensis</em> with middle Acheulean ones, repeatedly came to those well-drained spots. Single-purpose sites also exist in different environments and other ones provide evidence of hominins roaming through the plain.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113520"},"PeriodicalIF":2.7,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885193","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 : 2025-12-23DOI: 10.1016/j.palaeo.2025.113523
Yawen Cui , Menghan Li , Lilin Sun , Dandan Li , Guijie Zhang , Xiaolin Zhang , Yanan Shen
Pronounced perturbations to the global carbon cycle from the Late Permian to the Early Triassic are recorded as several large C-isotope excursions. However, the overall significance of these perturbations, as well as their environmental implications and biotic responses, remains to be better constrained. Here, we present high-resolution C-isotopic data of carbonate (δ13Ccarb) spanning the late Wuchiapingian to Early Triassic from the Jiangya and Chongyang sections, deposited along the northern margin of the middle Yangtze Platform. The C-isotope records show prominent δ13Ccarb excursions both near the Wuchiapingian-Changhsingian boundary (WCB) and end-Permian mass extinction (EPME), which can be correlated at regional to global scales. Sedimentological and geochemical observations suggest that enhanced remineralization of upwelled 12C-enriched dissolved organic carbon (DOC), driven by the incursion of anoxic/euxinic deep waters, likely contributed to the negative δ13Ccarb excursions observed near the WCB and EPME. Oxidative decay of this upwelled DOC would have consumed key oxidants, including oxygen and sulfate, thereby promoting the expansion of marine anoxic/euxinic conditions. A pronounced depth gradient in δ13Ccarb between coeval shallow- and deep-water settings further supports this mechanism and links the negative excursions to widespread anoxia/euxinia in the eastern Paleo-Tethys Ocean. Together, our data support that the expansion of oceanic anoxia/euxinia may have played a crucial role in driving the biotic crises associated with the WCB and EPME.
{"title":"Spatial-temporal carbon isotope changes during the late Wuchiapingian to Early Triassic in South China and their global environmental implications","authors":"Yawen Cui , Menghan Li , Lilin Sun , Dandan Li , Guijie Zhang , Xiaolin Zhang , Yanan Shen","doi":"10.1016/j.palaeo.2025.113523","DOIUrl":"10.1016/j.palaeo.2025.113523","url":null,"abstract":"<div><div>Pronounced perturbations to the global carbon cycle from the Late Permian to the Early Triassic are recorded as several large C-isotope excursions. However, the overall significance of these perturbations, as well as their environmental implications and biotic responses, remains to be better constrained. Here, we present high-resolution C-isotopic data of carbonate (δ<sup>13</sup>C<sub>carb</sub>) spanning the late Wuchiapingian to Early Triassic from the Jiangya and Chongyang sections, deposited along the northern margin of the middle Yangtze Platform. The C-isotope records show prominent δ<sup>13</sup>C<sub>carb</sub> excursions both near the Wuchiapingian-Changhsingian boundary (WCB) and end-Permian mass extinction (EPME), which can be correlated at regional to global scales. Sedimentological and geochemical observations suggest that enhanced remineralization of upwelled <sup>12</sup>C-enriched dissolved organic carbon (DOC), driven by the incursion of anoxic/euxinic deep waters, likely contributed to the negative δ<sup>13</sup>C<sub>carb</sub> excursions observed near the WCB and EPME. Oxidative decay of this upwelled DOC would have consumed key oxidants, including oxygen and sulfate, thereby promoting the expansion of marine anoxic/euxinic conditions. A pronounced depth gradient in δ<sup>13</sup>C<sub>carb</sub> between coeval shallow- and deep-water settings further supports this mechanism and links the negative excursions to widespread anoxia/euxinia in the eastern Paleo-Tethys Ocean. Together, our data support that the expansion of oceanic anoxia/euxinia may have played a crucial role in driving the biotic crises associated with the WCB and EPME.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"685 ","pages":"Article 113523"},"PeriodicalIF":2.7,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927944","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 : 2025-12-23DOI: 10.1016/j.palaeo.2025.113521
Hongyu Qi , Yali Zhou , Jiangli Pang , Xiaoke Qiang , Jiale Wang , Baofeng Ma , Tong Feng , Xichen Li , Yiting Zhao , Yingying Cui , Liping Jiang , Siying Yue
<div><div>Asian environment is characterized by the uplift of the Tibetan Plateau, the formation of the Asian monsoon, and inland aridification during Cenozoic. However, there are significant controversies regarding the evolutionary patterns of the Asian monsoon and the historical records of inland aridification documented by different carriers in different regions. The Otindag Sandy Land, one of the inland arid and semi-arid regions in northwestern China, is situated along the northern limit of the East Asian Summer Monsoon (EASM)—a boundary of the East Asian monsoon area—and is highly sensitive to climate change. Owing to extensive Cenozoic aeolian deposits developed in the area, it serves as an ideal region for studying past climate and environmental changes. Previous research on the chronology of sandy land has primarily focused on the Quaternary, with limited attention paid to the stratigraphic age of Neogene aeolian sediments, largely due to the absence of suitable geological markers. This study examined the basalt-lacustrine sand-aeolian red clay sedimentary sequence of the Wulangou section in the northern Otindag Sandy Land. Paleomagnetism was used to determine the magnetostratigraphy of the aeolian red clay, and the <sup>40</sup>Ar/<sup>39</sup>Ar isotope dating method was employed to obtain the absolute age of the basalt. Combined with stratigraphic correlations from the Baogeda Ula section, which is a standard stratigraphic section within the study area, and biostratigraphic ages of the Baodean Period, the ages of the lacustrine sand layers in the region were determined. This study established a complete chronological framework for the stratigraphic sedimentary sequence of the Wulangou section. Climate and environmental changes were analyzed based on the sedimentary characteristics, magnetic susceptibility, and grain size of the strata. The research results indicated that the red clay magnetic stratum captured the geomagnetic polarity sequence from C5n.2n to C4n.2n, spanning approximately 11.04–8.06 Ma. The ages of the three aeolian sand layers interbedded in the lower part of the red clay were 11.04–10.91 Ma, 10.51–10.44 Ma, and 10.37–10.23 Ma, respectively. Since the late Miocene, the climate of the northern Otindag Sandy Land has been predominantly cold and dry, undergoing a fluctuation that transitions from cold and dry, then shifts to warm and wet, and ultimately reverts back to cold and dry. From 11.04 to 10.02 Ma, red clay and aeolian sand interbedding developed, characterized by low magnetic susceptibility, coarser particles, and a relatively cold and dry climate with strong aeolian sand activity. Between 10.02 and 8.91 Ma, the magnetic susceptibility reached a high value stage with a finer grain size and relatively warm and humid climate. The weak and strong pedogenic layers in red clay were alternately developed. During 8.91–8.06 Ma, the red clay exhibited lower magnetic susceptibility and coarser grain size, with thick calca
{"title":"Magnetic chronology of the late Miocene Wulangou red clay sequences in the northern Otindag Sandy Land","authors":"Hongyu Qi , Yali Zhou , Jiangli Pang , Xiaoke Qiang , Jiale Wang , Baofeng Ma , Tong Feng , Xichen Li , Yiting Zhao , Yingying Cui , Liping Jiang , Siying Yue","doi":"10.1016/j.palaeo.2025.113521","DOIUrl":"10.1016/j.palaeo.2025.113521","url":null,"abstract":"<div><div>Asian environment is characterized by the uplift of the Tibetan Plateau, the formation of the Asian monsoon, and inland aridification during Cenozoic. However, there are significant controversies regarding the evolutionary patterns of the Asian monsoon and the historical records of inland aridification documented by different carriers in different regions. The Otindag Sandy Land, one of the inland arid and semi-arid regions in northwestern China, is situated along the northern limit of the East Asian Summer Monsoon (EASM)—a boundary of the East Asian monsoon area—and is highly sensitive to climate change. Owing to extensive Cenozoic aeolian deposits developed in the area, it serves as an ideal region for studying past climate and environmental changes. Previous research on the chronology of sandy land has primarily focused on the Quaternary, with limited attention paid to the stratigraphic age of Neogene aeolian sediments, largely due to the absence of suitable geological markers. This study examined the basalt-lacustrine sand-aeolian red clay sedimentary sequence of the Wulangou section in the northern Otindag Sandy Land. Paleomagnetism was used to determine the magnetostratigraphy of the aeolian red clay, and the <sup>40</sup>Ar/<sup>39</sup>Ar isotope dating method was employed to obtain the absolute age of the basalt. Combined with stratigraphic correlations from the Baogeda Ula section, which is a standard stratigraphic section within the study area, and biostratigraphic ages of the Baodean Period, the ages of the lacustrine sand layers in the region were determined. This study established a complete chronological framework for the stratigraphic sedimentary sequence of the Wulangou section. Climate and environmental changes were analyzed based on the sedimentary characteristics, magnetic susceptibility, and grain size of the strata. The research results indicated that the red clay magnetic stratum captured the geomagnetic polarity sequence from C5n.2n to C4n.2n, spanning approximately 11.04–8.06 Ma. The ages of the three aeolian sand layers interbedded in the lower part of the red clay were 11.04–10.91 Ma, 10.51–10.44 Ma, and 10.37–10.23 Ma, respectively. Since the late Miocene, the climate of the northern Otindag Sandy Land has been predominantly cold and dry, undergoing a fluctuation that transitions from cold and dry, then shifts to warm and wet, and ultimately reverts back to cold and dry. From 11.04 to 10.02 Ma, red clay and aeolian sand interbedding developed, characterized by low magnetic susceptibility, coarser particles, and a relatively cold and dry climate with strong aeolian sand activity. Between 10.02 and 8.91 Ma, the magnetic susceptibility reached a high value stage with a finer grain size and relatively warm and humid climate. The weak and strong pedogenic layers in red clay were alternately developed. During 8.91–8.06 Ma, the red clay exhibited lower magnetic susceptibility and coarser grain size, with thick calca","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"685 ","pages":"Article 113521"},"PeriodicalIF":2.7,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145872108","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 : 2025-12-23DOI: 10.1016/j.palaeo.2025.113522
Hao Xie , Caicai Liu , Dewen Zheng , Ying Wang , Jingxing Yu , Xudong Zhao , Zhuqi Zhang , Li Deng , Jiawei Zhang , Huiping Zhang
Constraining the initiation of intracontinental thrust faults is crucial for understanding deformation sequences that occurred during the growth of the Tibetan Plateau. This study investigates the activation timing of the nearly E–W-trending Qinghainan Shan and Gonghenan Shan thrust faults through integrated provenance analyses of Cenozoic sediments from the Chaka–Gonghe Basin, including sandstone petrography, heavy mineral assemblages, and detrital zircon U-Pb geochronology. Results reveal a pronounced provenance shift at ∼6–7 Ma, marked by a sharp increase in sediment derived from the adjacent Qinghainan Shan and Gonghenan Shan. This transition coincides with a decline in mineral maturity indices along with a change in the rotational trend, reflecting mountain uplift and constraining the initiation of these thrust faults to the late Miocene. Regionally, deformation propagated sequentially from WNW-trending strike-slip boundary faults to NNW-trending dextral strike-slip fault systems, and subsequently to intrablock thrusts. The late Miocene onset of these thrust faults represents a key kinematic step in strain partitioning, accommodating crustal shortening during the India–Asia convergence and facilitating the northeastward growth of the plateau. This progression from boundary faulting to distributed interior deformation supports a model of continuous, rather than rigid-block tectonic deformation during continental convergence.
{"title":"Late Miocene tectonic reorganization and regional development of thrust faulting in the northeastern Tibetan Plateau","authors":"Hao Xie , Caicai Liu , Dewen Zheng , Ying Wang , Jingxing Yu , Xudong Zhao , Zhuqi Zhang , Li Deng , Jiawei Zhang , Huiping Zhang","doi":"10.1016/j.palaeo.2025.113522","DOIUrl":"10.1016/j.palaeo.2025.113522","url":null,"abstract":"<div><div>Constraining the initiation of intracontinental thrust faults is crucial for understanding deformation sequences that occurred during the growth of the Tibetan Plateau. This study investigates the activation timing of the nearly E–W-trending Qinghainan Shan and Gonghenan Shan thrust faults through integrated provenance analyses of Cenozoic sediments from the Chaka–Gonghe Basin, including sandstone petrography, heavy mineral assemblages, and detrital zircon U-Pb geochronology. Results reveal a pronounced provenance shift at ∼6–7 Ma, marked by a sharp increase in sediment derived from the adjacent Qinghainan Shan and Gonghenan Shan. This transition coincides with a decline in mineral maturity indices along with a change in the rotational trend, reflecting mountain uplift and constraining the initiation of these thrust faults to the late Miocene. Regionally, deformation propagated sequentially from WNW-trending strike-slip boundary faults to NNW-trending dextral strike-slip fault systems, and subsequently to intrablock thrusts. The late Miocene onset of these thrust faults represents a key kinematic step in strain partitioning, accommodating crustal shortening during the India–Asia convergence and facilitating the northeastward growth of the plateau. This progression from boundary faulting to distributed interior deformation supports a model of continuous, rather than rigid-block tectonic deformation during continental convergence.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113522"},"PeriodicalIF":2.7,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842089","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 : 2025-12-22DOI: 10.1016/j.palaeo.2025.113524
Christopher T. Conwell , Matthew R. Saltzman , Anders Lindskog , Mats E. Eriksson , Elizabeth M. Griffith , Stephen A. Leslie , Cole T. Edwards , Olle Hints , Achim D. Herrmann
Despite frequent use of conodonts as an archive for seawater 87Sr/86Sr, available diagenetic screening tools are inconsistent predictors of primary seawater 87Sr/86Sr preservation. Here, we attempt to isolate variables affecting the preservation of seawater 87Sr/86Sr in conodonts. We present new Middle–Late Ordovician (∼470–450 Ma) conodont 87Sr/86Sr from mid-paleolatitude (30–45°S) carbonate successions from central Sweden (Fjäcka, Kårgärde) and Estonia (Uuga Cliff, Viki borehole) which have low Conodont Alteration Index (CAI) values of 1–1.5. Coeval 87Sr/86Sr measurements from Kårgärde and Estonian sections are offset from global seawater by ∼ +2 × 10−4 but preserve the overall structure of the seawater curve, suggesting minor diagenetic Sr exchange. 87Sr/86Sr measurements from the more argillaceous Fjäcka section show extensive alteration with highly radiogenic values as much as ∼6 × 10−4 greater than global seawater and a stratigraphic trend that diverges from the seawater curve. This may be explained by highly radiogenic Sr contribution from the Kinnekulle K-bentonite and Fjäcka shale units that occur at Fjäcka section.
We compiled 1164 conodont 87Sr/86Sr measurements spanning ∼485–250 Ma and categorized measurements by host rock, sample preparation, paleolatitude, and CAI. Boxplots and Mann-Whitney U testing of residual values relative to the seawater curve (87Sr/86Srconodont – 87Sr/86Srseawater) reveal that paleolatitude and associated differences in sedimentation rate affect preservation of seawater 87Sr/86Sr values in conodonts. The relative abundance of clay minerals did not significantly correlate with residual values for conodonts from mid- or low-latitude deposits. We recommend that future investigations of seawater 87Sr/86Sr records using conodont apatite target low-latitude settings with high sedimentation rate and CAI ≤ 2.
{"title":"Factors affecting 87Sr/86Sr preservation in conodont apatite: An example from the Ordovician of Baltoscandia","authors":"Christopher T. Conwell , Matthew R. Saltzman , Anders Lindskog , Mats E. Eriksson , Elizabeth M. Griffith , Stephen A. Leslie , Cole T. Edwards , Olle Hints , Achim D. Herrmann","doi":"10.1016/j.palaeo.2025.113524","DOIUrl":"10.1016/j.palaeo.2025.113524","url":null,"abstract":"<div><div>Despite frequent use of conodonts as an archive for seawater <sup>87</sup>Sr/<sup>86</sup>Sr, available diagenetic screening tools are inconsistent predictors of primary seawater <sup>87</sup>Sr/<sup>86</sup>Sr preservation. Here, we attempt to isolate variables affecting the preservation of seawater <sup>87</sup>Sr/<sup>86</sup>Sr in conodonts. We present new Middle–Late Ordovician (∼470–450 Ma) conodont <sup>87</sup>Sr/<sup>86</sup>Sr from mid-paleolatitude (30–45°S) carbonate successions from central Sweden (Fjäcka, Kårgärde) and Estonia (Uuga Cliff, Viki borehole) which have low Conodont Alteration Index (CAI) values of 1–1.5. Coeval <sup>87</sup>Sr/<sup>86</sup>Sr measurements from Kårgärde and Estonian sections are offset from global seawater by ∼ +2 × 10<sup>−4</sup> but preserve the overall structure of the seawater curve, suggesting minor diagenetic Sr exchange. <sup>87</sup>Sr/<sup>86</sup>Sr measurements from the more argillaceous Fjäcka section show extensive alteration with highly radiogenic values as much as ∼6 × 10<sup>−4</sup> greater than global seawater and a stratigraphic trend that diverges from the seawater curve. This may be explained by highly radiogenic Sr contribution from the Kinnekulle K-bentonite and Fjäcka shale units that occur at Fjäcka section.</div><div>We compiled 1164 conodont <sup>87</sup>Sr/<sup>86</sup>Sr measurements spanning ∼485–250 Ma and categorized measurements by host rock, sample preparation, paleolatitude, and CAI. Boxplots and Mann-Whitney U testing of residual values relative to the seawater curve (<sup>87</sup>Sr/<sup>86</sup>Sr<sub>conodont</sub> – <sup>87</sup>Sr/<sup>86</sup>Sr<sub>seawater</sub>) reveal that paleolatitude and associated differences in sedimentation rate affect preservation of seawater <sup>87</sup>Sr/<sup>86</sup>Sr values in conodonts. The relative abundance of clay minerals did not significantly correlate with residual values for conodonts from mid- or low-latitude deposits. We recommend that future investigations of seawater <sup>87</sup>Sr/<sup>86</sup>Sr records using conodont apatite target low-latitude settings with high sedimentation rate and CAI ≤ 2.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"685 ","pages":"Article 113524"},"PeriodicalIF":2.7,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145872109","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}
A high-resolution stalagmite δ18O record from Mawsmai Cave (MAW), spanning from ∼11,807 to 5622 calibrated years before present (cal yr BP), sheds light on the dynamics of the Indian Summer Monsoon (ISM). In the early Holocene (∼ 11,807–7700 cal yr BP) the decreased δ18O values suggest a period of intensified ISM, whereas in the middle Holocene (∼ 7700–5622 cal yr BP) the positive δ18O values demonstrate a weak ISM. Petrographic and mineralogical analyses suggest a correspondence between changes in stalagmite fabric and δ18O variability, implying a climatic control on stalagmite growth. The MAW record also depicts several multi-centennial scale ISM shifts that coincide with the Bond events 8, 7, 6, 5b, 5a, and 4, suggesting teleconnections between North Atlantic climate and ISM variability via changes in the Atlantic Meridional Overturning Circulation (AMOC). Spectral and continuous wavelet transform analyses of the MAW record reveal periodicities of ∼118 and ∼ 110 years, consistent with the centennial-scale Gleissberg solar cycles. These cyclicities indicate that solar variability in conjunction with coupled ocean–atmosphere dynamics, including the Pacific Decadal Oscillation (PDO) and the temperature gradient between the Tibetan Plateau and the Indian Ocean, played a dominant role in modulating ISM variability during the early to middle Holocene.
Mawsmai洞穴（MAW）的高分辨率石笋δ18O记录，跨度为距今约11,807至5622校准年（cal yr BP），揭示了印度夏季风（ISM）的动力学。在全新世早期（~ 11,807 ~ 7700 cal yr BP）， δ18O值的下降表明了ISM的增强，而在全新世中期（~ 7700 ~ 5622 cal yr BP）， δ18O值的上升表明ISM的减弱。岩石学和矿物学分析表明，石笋结构的变化与δ18O变率之间存在对应关系，表明气候控制了石笋的生长。MAW记录还描述了与Bond事件8、7、6、5b、5a和4相吻合的几次百年尺度ISM变化，表明北大西洋气候与ISM变率之间通过大西洋经向翻转环流（AMOC）的变化存在远相关。MAW记录的光谱和连续小波变换分析显示周期为~ 118年和~ 110年，与百年尺度的Gleissberg太阳周期一致。这些周期表明，在全新世早期至中期，太阳变率与太平洋年代际涛动（PDO）和青藏高原与印度洋之间的温度梯度等海洋-大气耦合动力学在调节ISM变率中起主导作用。
{"title":"Deciphering Holocene monsoon dynamics in northeastern India using speleothem δ18O record and petrography","authors":"Yachna Verma , Anil K. Gupta , Prasanta Sanyal , Priyantan Gupta , Som Dutt , Pankaj Kumar , Abhijit Mukherjee","doi":"10.1016/j.palaeo.2025.113518","DOIUrl":"10.1016/j.palaeo.2025.113518","url":null,"abstract":"<div><div>A high-resolution stalagmite δ<sup>18</sup>O record from Mawsmai Cave (MAW), spanning from ∼11,807 to 5622 calibrated years before present (cal yr BP), sheds light on the dynamics of the Indian Summer Monsoon (ISM). In the early Holocene (∼ 11,807–7700 cal yr BP) the decreased δ<sup>18</sup>O values suggest a period of intensified ISM, whereas in the middle Holocene (∼ 7700–5622 cal yr BP) the positive δ<sup>18</sup>O values demonstrate a weak ISM. Petrographic and mineralogical analyses suggest a correspondence between changes in stalagmite fabric and δ<sup>18</sup>O variability, implying a climatic control on stalagmite growth. The MAW record also depicts several multi-centennial scale ISM shifts that coincide with the Bond events 8, 7, 6, 5b, 5a, and 4, suggesting teleconnections between North Atlantic climate and ISM variability via changes in the Atlantic Meridional Overturning Circulation (AMOC). Spectral and continuous wavelet transform analyses of the MAW record reveal periodicities of ∼118 and ∼ 110 years, consistent with the centennial-scale Gleissberg solar cycles. These cyclicities indicate that solar variability in conjunction with coupled ocean–atmosphere dynamics, including the Pacific Decadal Oscillation (PDO) and the temperature gradient between the Tibetan Plateau and the Indian Ocean, played a dominant role in modulating ISM variability during the early to middle Holocene.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113518"},"PeriodicalIF":2.7,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842086","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 : 2025-12-20DOI: 10.1016/j.palaeo.2025.113507
Shuaicai Wu , Lei Chen , Wen Liu , Weiliang Kong , Min Xiong , Xiangyu Liu , Xiucheng Tan , Zuyou Zhang , Chongjie Liao
{"title":"Corrigendum to “Orbital-scale palaeoclimate and palaeoceanographic evolution in the late Permian Western Hubei Trough, South China” [Palaeogeography, Palaeoclimatology, Palaeoecology (2025) 113466]","authors":"Shuaicai Wu , Lei Chen , Wen Liu , Weiliang Kong , Min Xiong , Xiangyu Liu , Xiucheng Tan , Zuyou Zhang , Chongjie Liao","doi":"10.1016/j.palaeo.2025.113507","DOIUrl":"10.1016/j.palaeo.2025.113507","url":null,"abstract":"","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113507"},"PeriodicalIF":2.7,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885195","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 : 2025-12-18DOI: 10.1016/j.palaeo.2025.113514
Jie Wei, An Wang, Tianyi Shen, Ganyu Lyu, Haoruo Li, Guocan Wang
During the Neogene, the crustal deformation in the southern Tibetan Plateau propagated southward from the Gangdese Mountains to the Himalaya. This propagation provides a perspective for exploring Himalayan crustal shortening and topographic development through the tectonic history of the Gangdese Mountains. In this paper, we present new thermochronological data (16 apatite (UTh)/He, 25 apatite fission-track, and 23 zircon fission-track ages) from the southern Gangdese Mountains, which delineate a detailed history of attenuating rates of exhumation during the Neogene. Specifically, the southern margin of the Gangdese Mountains is characterized by a rapid exhumation (∼1.08 mm/yr) in the early Miocene, followed by a moderate rate of ∼0.27 mm/yr between 16 and 11 Ma, and subsequently a steady, lower exhumation rate of ∼0.18 mm/yr since 11–8 Ma. These progressively decreasing exhumation rates, interpreted as tectonically driven and coupled with the southward propagation of deformation in the Himalaya, correspond to an inverse correlation in partitioned shortening rates between the Himalaya and the Gangdese Mountains. This relationship enables a first-order estimation of Himalayan crustal shortening based on the tectonically determined exhumation rate in the Gangdese Mountains. Our data and analysis estimate total Neogene crustal shortening of ∼417–522 km across Himalaya, consistent with previous structural studies. Crustal thickening predicted by this shortening supports the interpretation that the modern crustal thickness and paleoelevation of the Himalaya were largely attained by the late Miocene.
{"title":"Reduction in the rate of exhumation of the Gangdese Mountains (Tibetan Plateau) through the Neogene and its implications for crustal shortening of the Himalaya","authors":"Jie Wei, An Wang, Tianyi Shen, Ganyu Lyu, Haoruo Li, Guocan Wang","doi":"10.1016/j.palaeo.2025.113514","DOIUrl":"10.1016/j.palaeo.2025.113514","url":null,"abstract":"<div><div>During the Neogene, the crustal deformation in the southern Tibetan Plateau propagated southward from the Gangdese Mountains to the Himalaya. This propagation provides a perspective for exploring Himalayan crustal shortening and topographic development through the tectonic history of the Gangdese Mountains. In this paper, we present new thermochronological data (16 apatite (U<img>Th)/He, 25 apatite fission-track, and 23 zircon fission-track ages) from the southern Gangdese Mountains, which delineate a detailed history of attenuating rates of exhumation during the Neogene. Specifically, the southern margin of the Gangdese Mountains is characterized by a rapid exhumation (∼1.08 mm/yr) in the early Miocene, followed by a moderate rate of ∼0.27 mm/yr between 16 and 11 Ma, and subsequently a steady, lower exhumation rate of ∼0.18 mm/yr since 11–8 Ma. These progressively decreasing exhumation rates, interpreted as tectonically driven and coupled with the southward propagation of deformation in the Himalaya, correspond to an inverse correlation in partitioned shortening rates between the Himalaya and the Gangdese Mountains. This relationship enables a first-order estimation of Himalayan crustal shortening based on the tectonically determined exhumation rate in the Gangdese Mountains. Our data and analysis estimate total Neogene crustal shortening of ∼417–522 km across Himalaya, consistent with previous structural studies. Crustal thickening predicted by this shortening supports the interpretation that the modern crustal thickness and paleoelevation of the Himalaya were largely attained by the late Miocene.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113514"},"PeriodicalIF":2.7,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799341","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 : 2025-12-18DOI: 10.1016/j.palaeo.2025.113499
K.V. Sarath , K. Sandeep , Alka Absur , Namitha Ajay , Poonam Verma , Yogesh P. Singh , A.K. Rafaz , V. Nandakumar , G. Indu , E. Shaji
The Warkalli Formation represents a key Neogene sedimentary archive along the south-western coast of India. This study examines the northern extension of the Formation exposed around Cheruvathur village, Kerala, integrating sedimentological, geochemical, and palynological data to reconstruct provenance, weathering conditions, palaeovegetation, and depositional environment. The succession is composed of arenaceous–argillaceous sediments capped by laterite and is classified into four facies associations: floodplain, active channel, lagoonal/lacustrine, and dune–beach transition facies, indicating major shifts in fluvial dynamics and changes in the coastline. Extremely high values of Chemical Index of Alteration and Fe-Al enrichment suggest intense tropical chemical weathering and derivation from nearby felsic to intermediate basement rocks, with minor mafic contributions. Pollen spectra dominated by pteridophyte spores and angiosperm pollen, along with fungal remains, indicate warm and humid climatic conditions with freshwater to coastal vegetation and episodic tidal influence. These observations collectively imply strong monsoonal forcing, short sediment transport, and fluctuating sea levels during the Mio-Pliocene. The study provides new insights into Neogene palaeoenvironmental evolution along the passive western margin of India and highlights the climatic sensitivity of tropical coastal depositional systems.
{"title":"New insights into the Neogene sedimentary Formations of south-western India: Implications for provenance, palaeovegetation and depositional environment","authors":"K.V. Sarath , K. Sandeep , Alka Absur , Namitha Ajay , Poonam Verma , Yogesh P. Singh , A.K. Rafaz , V. Nandakumar , G. Indu , E. Shaji","doi":"10.1016/j.palaeo.2025.113499","DOIUrl":"10.1016/j.palaeo.2025.113499","url":null,"abstract":"<div><div>The Warkalli Formation represents a key Neogene sedimentary archive along the south-western coast of India. This study examines the northern extension of the Formation exposed around Cheruvathur village, Kerala, integrating sedimentological, geochemical, and palynological data to reconstruct provenance, weathering conditions, palaeovegetation, and depositional environment. The succession is composed of arenaceous–argillaceous sediments capped by laterite and is classified into four facies associations: floodplain, active channel, lagoonal/lacustrine, and dune–beach transition facies, indicating major shifts in fluvial dynamics and changes in the coastline. Extremely high values of Chemical Index of Alteration and Fe-Al enrichment suggest intense tropical chemical weathering and derivation from nearby felsic to intermediate basement rocks, with minor mafic contributions. Pollen spectra dominated by pteridophyte spores and angiosperm pollen, along with fungal remains, indicate warm and humid climatic conditions with freshwater to coastal vegetation and episodic tidal influence. These observations collectively imply strong monsoonal forcing, short sediment transport, and fluctuating sea levels during the Mio-Pliocene. The study provides new insights into Neogene palaeoenvironmental evolution along the passive western margin of India and highlights the climatic sensitivity of tropical coastal depositional systems.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113499"},"PeriodicalIF":2.7,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842085","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 : 2025-12-17DOI: 10.1016/j.palaeo.2025.113516
Shuo Wang , Yuzhu Zhang , Ninglian Wang , Zhiheng Du , Yan Zhu , Peng Cheng , Yuda Chui
Antarctica's postglacial ice-free regions preserve sedimentary archives that are critical for reconstructing relative sea-level (RSL) changes and glacial-isostatic adjustment (GIA). This study presents a 37 cm sediment core from a coastal isolation basin (NYD Lake) on Inexpressible Island in Terra Nova Bay, Ross Sea. The basin's retaining sill is currently 1.1 m above mean sea level. The core spans the past ∼7400 calibrated years and captures a clear environmental transition from a tidal marine setting to a semi-enclosed lacustrine system. Three depositional units are identified: (1) a lower marine unit (below 18 cm; prior to ∼3500 cal yr BP) composed of coarse sand with high sulfur content, indicating strong tidal influence; (2) a transitional unit (18–7 cm) with mixed marine and freshwater signatures, reflecting gradual isolation; and (3) an upper lacustrine unit (above 7 cm; since ∼1700 cal yr BP), characterized by fine silt and organic geochemistry dominated by freshwater algal input but still subject to tidal or wave influence. C/N ratios and δ13C values indicate that the source of sedimentary organic matter shifted from a marine–terrestrial mixture to primarily freshwater algal origin after ∼1700 cal yr BP. This transition marks the isolation of the NYD Lake, coinciding with the sill emerging above sea level. Using the sill elevation and the timing of isolation, we estimate a crustal uplift rate of 0.65 ± 0.17 mm/yr. This record provides rare empirical constraints on Holocene RSL changes in the Terra Nova Bay and contributes to improving GIA models and understanding coastal evolution along the western Ross Sea margin.
南极洲冰期后无冰区保存着沉积档案，这些档案对于重建相对海平面（RSL）变化和冰川均衡调整（GIA）至关重要。本文研究了罗斯海特拉诺瓦湾不可表达岛（Inexpressible Island）海岸隔离盆地（NYD Lake）的37 cm沉积物岩心。目前，该盆地的挡土坝高出平均海平面1.1米。岩心跨越过去~ 7400校准年，捕捉了从潮汐海洋环境到半封闭湖泊系统的清晰环境转变。确定了3个沉积单元：(1)较低的海洋单元（低于18 cm；早于~ 3500 cal yr BP），由高含硫量的粗砂组成，表明潮汐的强烈影响；(2)过渡性单元（18-7厘米），具有海洋和淡水混合特征，反映出逐渐隔离；(3)上湖单元（7cm以上；自~ 1700 cal yr BP以来），特征为细粉砂和有机地球化学，以淡水藻类输入为主，但仍受潮汐或波浪影响。C/N比值和δ13C值表明，在~ 1700 cal yr BP之后，沉积有机质的来源从海陆生混合物转变为主要的淡水藻类来源。这种转变标志着纽约湖的孤立，与海平面以上的岩石相吻合。根据基台高程和隔离时间，我们估计地壳隆升速率为0.65±0.17 mm/yr。该记录为特拉诺瓦湾全新世RSL变化提供了罕见的经验约束，有助于改进GIA模型和理解罗斯海西部边缘的沿海演变。
{"title":"Mid-holocene environmental changes and glacial-isostatic uplift recorded in a coastal isolation basin on inexpressible Island, Ross Sea, Antarctica","authors":"Shuo Wang , Yuzhu Zhang , Ninglian Wang , Zhiheng Du , Yan Zhu , Peng Cheng , Yuda Chui","doi":"10.1016/j.palaeo.2025.113516","DOIUrl":"10.1016/j.palaeo.2025.113516","url":null,"abstract":"<div><div>Antarctica's postglacial ice-free regions preserve sedimentary archives that are critical for reconstructing relative sea-level (RSL) changes and glacial-isostatic adjustment (GIA). This study presents a 37 cm sediment core from a coastal isolation basin (NYD Lake) on Inexpressible Island in Terra Nova Bay, Ross Sea. The basin's retaining sill is currently 1.1 m above mean sea level. The core spans the past ∼7400 calibrated years and captures a clear environmental transition from a tidal marine setting to a semi-enclosed lacustrine system. Three depositional units are identified: (1) a lower marine unit (below 18 cm; prior to ∼3500 cal yr BP) composed of coarse sand with high sulfur content, indicating strong tidal influence; (2) a transitional unit (18–7 cm) with mixed marine and freshwater signatures, reflecting gradual isolation; and (3) an upper lacustrine unit (above 7 cm; since ∼1700 cal yr BP), characterized by fine silt and organic geochemistry dominated by freshwater algal input but still subject to tidal or wave influence. C/N ratios and δ<sup>13</sup>C values indicate that the source of sedimentary organic matter shifted from a marine–terrestrial mixture to primarily freshwater algal origin after ∼1700 cal yr BP. This transition marks the isolation of the NYD Lake, coinciding with the sill emerging above sea level. Using the sill elevation and the timing of isolation, we estimate a crustal uplift rate of 0.65 ± 0.17 mm/yr. This record provides rare empirical constraints on Holocene RSL changes in the Terra Nova Bay and contributes to improving GIA models and understanding coastal evolution along the western Ross Sea margin.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"684 ","pages":"Article 113516"},"PeriodicalIF":2.7,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842084","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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