Pub Date : 2026-03-11DOI: 10.1016/j.gloplacha.2026.105429
Simin Peng, Yu Li, Zhansen Zhang, Zhi Zhang, Yong Ge
{"title":"Seasonal jet stream dominates spatiotemporal heterogeneity of dry-wet status in arid Central Asia since the Holocene","authors":"Simin Peng, Yu Li, Zhansen Zhang, Zhi Zhang, Yong Ge","doi":"10.1016/j.gloplacha.2026.105429","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2026.105429","url":null,"abstract":"","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147447953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-03-11DOI: 10.1016/j.gloplacha.2026.105428
Mengyue Duan, Jörg Robl, Franz Neubauer, Anne-Laure Argentin, Moritz Liebl, Flora Boekhout
{"title":"Northeastward growth of the Tibetan Plateau recorded in the drainage network of the Ordos Loess Plateau","authors":"Mengyue Duan, Jörg Robl, Franz Neubauer, Anne-Laure Argentin, Moritz Liebl, Flora Boekhout","doi":"10.1016/j.gloplacha.2026.105428","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2026.105428","url":null,"abstract":"","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"62 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147447956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-03-09DOI: 10.1016/j.gloplacha.2026.105426
Christian Leipe, Moritz Nykamp, Philipp Hoelzmann, David Handfried, Alexander A. Shchetnikov, Elena V. Bezrukova, Mayke Wagner, Pavel E. Tarasov
The North Atlantic climate has been suggested to exert a major control on the hydroclimate of Inner Asia, but the direction and persistence of the temperature–moisture relationship remain unclear. Here, we present new varve-chronology-constrained geochemical records from Lake Shira in northern Inner Asia, revealing a cyclical succession of centennial-scale wet-dry climate intervals over the past ~2500 years. Wet periods with high lake levels are interrupted by three arid intervals (350–479 CE, 1459–1534 CE, 1898–1928 CE), marked by low lake levels, high salinity and holomixis. The wet intervals coincide with the Roman Warm Period, the Medieval Warm Period and the middle–late Little Ice Age (LIA), and the dry phases with cold spells associated with the Dark Ages Cold Period and the beginning and end of the LIA. A phase of less intense aridity 349–296 BCE overlaps with the end of the Iron Age Cold Period. A thorough review of published climate data and our own findings shows that this pattern is primarily driven by thermal conditions in the North Atlantic region, where higher sea surface temperatures (reflected in elevated Atlantic Multidecadal Oscillation indices) promote more positive North Atlantic Oscillation states and intensify mid-latitude westerly moisture transport. Comparison of varve thickness measurements with observed/reconstructed climate records for the past 150 years indicates that sedimentation rate is mainly controlled by fluvial discharge to the lake. Although varve thickness tends to be negatively correlated with precipitation and temperature, several notable exceptions limit its use as independent climate proxy.
{"title":"High-resolution hydroclimatic variability in northern Inner Asia in response to North Atlantic temperature changes during the last 2500 years","authors":"Christian Leipe, Moritz Nykamp, Philipp Hoelzmann, David Handfried, Alexander A. Shchetnikov, Elena V. Bezrukova, Mayke Wagner, Pavel E. Tarasov","doi":"10.1016/j.gloplacha.2026.105426","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2026.105426","url":null,"abstract":"The North Atlantic climate has been suggested to exert a major control on the hydroclimate of Inner Asia, but the direction and persistence of the temperature–moisture relationship remain unclear. Here, we present new varve-chronology-constrained geochemical records from Lake Shira in northern Inner Asia, revealing a cyclical succession of centennial-scale wet-dry climate intervals over the past ~2500 years. Wet periods with high lake levels are interrupted by three arid intervals (350–479 CE, 1459–1534 CE, 1898–1928 CE), marked by low lake levels, high salinity and holomixis. The wet intervals coincide with the Roman Warm Period, the Medieval Warm Period and the middle–late Little Ice Age (LIA), and the dry phases with cold spells associated with the Dark Ages Cold Period and the beginning and end of the LIA. A phase of less intense aridity 349–296 BCE overlaps with the end of the Iron Age Cold Period. A thorough review of published climate data and our own findings shows that this pattern is primarily driven by thermal conditions in the North Atlantic region, where higher sea surface temperatures (reflected in elevated Atlantic Multidecadal Oscillation indices) promote more positive North Atlantic Oscillation states and intensify mid-latitude westerly moisture transport. Comparison of varve thickness measurements with observed/reconstructed climate records for the past 150 years indicates that sedimentation rate is mainly controlled by fluvial discharge to the lake. Although varve thickness tends to be negatively correlated with precipitation and temperature, several notable exceptions limit its use as independent climate proxy.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"10 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147392406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-03-07DOI: 10.1016/j.gloplacha.2026.105423
N.K. Davi, L. Andreu-Hayles, C. Leland, A. Pacheco-Solana, M.P. Rao, E.R. Cook, N. Pederson
Climate change is intensifying hurricanes. Understanding the occurrence and impact of past storm events on forests provides a critical historical context for recent and projected changes in hurricane activity. Strong winds, flooding, and saltwater inundation from hurricanes can damage the canopy and roots of trees that, in turn, can leave a distinct signature in different tree-ring parameters. Here, we evaluate hurricane impacts from major storms (Category 2–5) on tree-ring width records from three coastal oak forests from New York and Rhode Island, USA. We analyze additional parameters (earlywood/latewood width and anatomical traits) in Montauk, New York to better understand the mechanisms of how a storm signature manifests in different tree-ring features. We find a significant reduction of ring width (RW) and latewood (LW) width, and an increase in the ratio of lumen area to total ring area (LAR) in the year following major hurricane events. These results illustrate a significant impact of hurricanes on the growth and physiological functioning of coastal oak trees. Furthermore, when RW and LAR were used in a combined approach, the effectiveness of pinpointing hurricanes increased, suggesting potential to reconstruct hurricane events prior to the historical record. Our findings also show a negative association between tree radial growth and sea-level height anomalies over the last few decades, emphasizing the continuous rise in sea level as a serious threat to these coastal ecosystems.
{"title":"Identifying hurricane and sea-level rise signatures in coastal oak forests of the Northeastern United States using a multi-parameter approach","authors":"N.K. Davi, L. Andreu-Hayles, C. Leland, A. Pacheco-Solana, M.P. Rao, E.R. Cook, N. Pederson","doi":"10.1016/j.gloplacha.2026.105423","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2026.105423","url":null,"abstract":"Climate change is intensifying hurricanes. Understanding the occurrence and impact of past storm events on forests provides a critical historical context for recent and projected changes in hurricane activity. Strong winds, flooding, and saltwater inundation from hurricanes can damage the canopy and roots of trees that, in turn, can leave a distinct signature in different tree-ring parameters. Here, we evaluate hurricane impacts from major storms (Category 2–5) on tree-ring width records from three coastal oak forests from New York and Rhode Island, USA. We analyze additional parameters (earlywood/latewood width and anatomical traits) in Montauk, New York to better understand the mechanisms of how a storm signature manifests in different tree-ring features. We find a significant reduction of ring width (RW) and latewood (LW) width, and an increase in the ratio of lumen area to total ring area (LAR) in the year following major hurricane events. These results illustrate a significant impact of hurricanes on the growth and physiological functioning of coastal oak trees. Furthermore, when RW and LAR were used in a combined approach, the effectiveness of pinpointing hurricanes increased, suggesting potential to reconstruct hurricane events prior to the historical record. Our findings also show a negative association between tree radial growth and sea-level height anomalies over the last few decades, emphasizing the continuous rise in sea level as a serious threat to these coastal ecosystems.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"64 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147392411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-03-06DOI: 10.1016/j.gloplacha.2026.105415
Alan Haywood, Muhammad Mubashar Dogar, Ran Feng, Gabriel Pontes, Christian Stepanek
{"title":"GPC climate/atmosphere section remit","authors":"Alan Haywood, Muhammad Mubashar Dogar, Ran Feng, Gabriel Pontes, Christian Stepanek","doi":"10.1016/j.gloplacha.2026.105415","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2026.105415","url":null,"abstract":"","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"32 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147392458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-03-06DOI: 10.1016/j.gloplacha.2026.105398
Kui Tong, Jinxi Li, Shugen Liu, I. Tonguç Uysal, Andrew Todd, Zijian Wang, Lu Zeng, Tian Hua, Zhiwu Li
Quantifying the potential temporal and spatial relationships between tectonics and surface-process changes remains challenging, but is critical to understanding the tectono-topographic evolution and geodynamic mechanisms of the Tibetan Plateau. In this study, we combine KAr dating of authigenic illite-bearing fault gouge, structural and clay mineralogical analyses to provide a direct temporal constraint on fault activation of the Lancangjiang fault (LCJF) in the SE Tibetan Plateau, which links to the rapid incision of the Lancang River. The resulting ages suggest that the LCJF has undergone at least high temperature (> ~250 °C) thrusting and brittle reactivation at ~51 Ma and ~ 2.4 Ma, respectively. The thrusting of the LCJF at ~51 Ma is related to the far-field stress effect of the hard India-Eurasia collision. The brittle reactivation of the LCJF at ~2.4 Ma is characterized by transpressional thrusting, which can be interpreted as being triggered by the southeastward extrusion of the Chuandian Block. The Early Pleistocene brittle thrusting of the LCJF is temporally consistent with the rapid valley incision within the Lancang River kinckzone, suggesting that tectonics is the primary factor controlling the incision of the Lancang River. Our work highlights that the illite-bearing fault gouge dating, which directly constrains the timing of brittle deformation of topographically prominent faults, has great potential for understanding drainage evolution and the associated geodynamics.
{"title":"Mid-Eocene thrusting and early Pleistocene brittle reactivation of the Lancangjiang fault and their implications for the incision of the Lancang River in the SE Tibetan Plateau","authors":"Kui Tong, Jinxi Li, Shugen Liu, I. Tonguç Uysal, Andrew Todd, Zijian Wang, Lu Zeng, Tian Hua, Zhiwu Li","doi":"10.1016/j.gloplacha.2026.105398","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2026.105398","url":null,"abstract":"Quantifying the potential temporal and spatial relationships between tectonics and surface-process changes remains challenging, but is critical to understanding the tectono-topographic evolution and geodynamic mechanisms of the Tibetan Plateau. In this study, we combine K<ce:glyph name=\"sbnd\"></ce:glyph>Ar dating of authigenic illite-bearing fault gouge, structural and clay mineralogical analyses to provide a direct temporal constraint on fault activation of the Lancangjiang fault (LCJF) in the SE Tibetan Plateau, which links to the rapid incision of the Lancang River. The resulting ages suggest that the LCJF has undergone at least high temperature (> ~250 °C) thrusting and brittle reactivation at ~51 Ma and ~ 2.4 Ma, respectively. The thrusting of the LCJF at ~51 Ma is related to the far-field stress effect of the hard India-Eurasia collision. The brittle reactivation of the LCJF at ~2.4 Ma is characterized by transpressional thrusting, which can be interpreted as being triggered by the southeastward extrusion of the Chuandian Block. The Early Pleistocene brittle thrusting of the LCJF is temporally consistent with the rapid valley incision within the Lancang River kinckzone, suggesting that tectonics is the primary factor controlling the incision of the Lancang River. Our work highlights that the illite-bearing fault gouge dating, which directly constrains the timing of brittle deformation of topographically prominent faults, has great potential for understanding drainage evolution and the associated geodynamics.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"19 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147392460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Dongsheng region of the Ordos Basin (China) contains important sandstone-hosted uranium deposits that reveal an evolving interaction of geochemical evolution and tectono-sedimentary dynamics. The present work combines whole-rock and carbon‑sulfur isotopic compositions to understand the origin and formation of uranium metallogeny within the Middle Jurassic intracontinental Zhiluo Formation of the Ordos Basin. The δ13C values (−26.7‰ to −2.2‰) of calcite-cement indicate that the carbon mainly originated through biochemical remineralization. Negative and variable δ13C values indicate a strong biogenic carbon contribution, while positive excursions reflect mantle or inorganic inputs. Additionally, the δ34S composition (−25.2‰ to 10.2‰) indicates the mutual inputs from bacterial sulfate reduction and Rayleigh fractionation. The broad δ34S range of pyrite similarly points to multiple sources, with a strong bacterial sulfate reduction signal. Trace element patterns show Light Rare Earth Element (LREE) enrichment, Heavy Rare Earth Elements (HREE) depletion, and distinctive “W-shaped” anomalies (e.g., Nd, Nb, Zr), consistent with reductive immobilization under diagenetic conditions. Tectonic reconstruction and sedimentary provenance support a deposition along an active continental margin with felsic to intermediate source rocks. The Zhiluo Formation was deposited in arid to semi-arid settings, as evidenced by low Rb/Sr and high Sr/Cu and Sr/Ba ratios, reflecting high paleosalinity and strong evaporation. A revised genetic model is here proposed in which oxidized uranium-bearing groundwater interacts with both locally derived organic matter and hydrocarbon-charged reducing fluids (e.g., CH4, CO, H2S, CO2) along structurally controlled fluid pathways, resulting in redox-driven uranium precipitation. This integrated isotopic–geochemical framework not only refines the mineralization model for the Dongsheng deposit but also provides a predictive approach for uranium exploration in analogous basinal settings worldwide. Our outcomes stress the wider role of microbial-hydrocarbon cycling in modulating uranium deposits across continental settings.
{"title":"Geochemical and isotopic insights into uranium mineralization in the Dongsheng Area (Ordos Basin, NW China): Implications for global uranium systems","authors":"Shamim Akhtar , Tehseen Zafar , Xiaoyong Yang , Fabrizio Frontalini","doi":"10.1016/j.gloplacha.2026.105313","DOIUrl":"10.1016/j.gloplacha.2026.105313","url":null,"abstract":"<div><div>The Dongsheng region of the Ordos Basin (China) contains important sandstone-hosted uranium deposits that reveal an evolving interaction of geochemical evolution and tectono-sedimentary dynamics. The present work combines whole-rock and carbon‑sulfur isotopic compositions to understand the origin and formation of uranium metallogeny within the Middle Jurassic intracontinental Zhiluo Formation of the Ordos Basin. The δ<sup>13</sup>C values (−26.7‰ to −2.2‰) of calcite-cement indicate that the carbon mainly originated through biochemical remineralization. Negative and variable δ<sup>13</sup>C values indicate a strong biogenic carbon contribution, while positive excursions reflect mantle or inorganic inputs. Additionally, the δ<sup>34</sup>S composition (−25.2‰ to 10.2‰) indicates the mutual inputs from bacterial sulfate reduction and Rayleigh fractionation. The broad δ<sup>34</sup>S range of pyrite similarly points to multiple sources, with a strong bacterial sulfate reduction signal. Trace element patterns show Light Rare Earth Element (LREE) enrichment, Heavy Rare Earth Elements (HREE) depletion, and distinctive “W-shaped” anomalies (e.g., Nd, Nb, Zr), consistent with reductive immobilization under diagenetic conditions. Tectonic reconstruction and sedimentary provenance support a deposition along an active continental margin with felsic to intermediate source rocks. The Zhiluo Formation was deposited in arid to semi-arid settings, as evidenced by low Rb/Sr and high Sr/Cu and Sr/Ba ratios, reflecting high paleosalinity and strong evaporation. A revised genetic model is here proposed in which oxidized uranium-bearing groundwater interacts with both locally derived organic matter and hydrocarbon-charged reducing fluids (e.g., CH<sub>4</sub>, CO, H<sub>2</sub>S, CO<sub>2</sub>) along structurally controlled fluid pathways, resulting in redox-driven uranium precipitation. This integrated isotopic–geochemical framework not only refines the mineralization model for the Dongsheng deposit but also provides a predictive approach for uranium exploration in analogous basinal settings worldwide. Our outcomes stress the wider role of microbial-hydrocarbon cycling in modulating uranium deposits across continental settings.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"258 ","pages":"Article 105313"},"PeriodicalIF":4.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-03-01Epub Date: 2025-12-19DOI: 10.1016/j.gloplacha.2025.105265
Munirdin Tohti , Wenjiao Xiao , Qigui Mao , Miao Sang , Zhiguo An , Qingyun Di , Yibo Wang , Liang Zhao
The Western Kunlun Orogen (WKO), located on the northwestern margin of the Tibetan Plateau, is considered as an accretionary orogen that preserves the entire tectonic evolution of the Tethyan oceans. Its Paleozoic to early Mesozoic orogenic history is crucial for reconstructing the Paleo-Asian plate, as it occupies a key tectonic position at the junction of the Pan-Asian and Tethyan tectonic domains. However, considerable dispute exists regarding its long-term orogenic process, particularly concerning the closure timings, positions, and subduction polarity of the Proto -Tethys and Paleo-Tethys Ocean in the WKO. The main cause of these controversies is the lack of a high-resolution lithospheric structure in this area. To clarify and gain deeper insights into the orogenic processes of Tethys, a 350-km-long Magnetotelluric (MT) profile, consisting of 32 broadband sounding stations, was deployed across the Tarim Basin (TB), Northern Kunlun Terrane (NKT), Southern Kunlun Terrane (SKT), Mazar Accretionary prism, and Karakorum Terrane (KKT) to collect field data for at least 36 h. Dimensionality analysis indicated that a 2D analysis was valid. The MT data were rotated to a 150° direction before inversion, based on an electrical principal strike analysis. The MT data were then imaged through a joint inversion of Transverse Electric Field (TE) and Transverse Magnetic Field (TM) modes using a nonlinear conjugate gradient (NLCG) algorithm. The resulting model provides crucial new constraints on the lithospheric structure beneath the WKO, revealing several distinct resistive anomalies. The bidirectional dipping geometry of these anomalies, integrated with geochronological and geochemical evidence, reveals two distinct subduction systems: one between the Northern and Southern Kunlun terranes, representing the subduction polarity of Proto-Tethys Ocean, and another between the Southern Kunlun and Karakorum terranes, recording the subduction process of Paleo-Tethys Ocean. Additionally, we interpret two resistive lower crust-uppermost mantle structures beneath the Mazar accretionary prism as a delaminated oceanic slab. Concurrently, a large, interconnected high-conductivity zone from the crust to the upper mantle is identified, likely reflecting partial melting due to asthenospheric upwelling triggered by Mid-Jurassic slab delamination. Furthermore, we propose that these pre-existing weak zones ultimately facilitated the Cenozoic deformation and uplift of the Kunlun Mountains during the ongoing India-Asia collision.
{"title":"Two-dimensional lithospheric electrical structure and implications for the geodynamic process of the Western Kunlun Orogen","authors":"Munirdin Tohti , Wenjiao Xiao , Qigui Mao , Miao Sang , Zhiguo An , Qingyun Di , Yibo Wang , Liang Zhao","doi":"10.1016/j.gloplacha.2025.105265","DOIUrl":"10.1016/j.gloplacha.2025.105265","url":null,"abstract":"<div><div>The Western Kunlun Orogen (WKO), located on the northwestern margin of the Tibetan Plateau, is considered as an accretionary orogen that preserves the entire tectonic evolution of the Tethyan oceans. Its Paleozoic to early Mesozoic orogenic history is crucial for reconstructing the Paleo-Asian plate, as it occupies a key tectonic position at the junction of the Pan-Asian and Tethyan tectonic domains. However, considerable dispute exists regarding its long-term orogenic process, particularly concerning the closure timings, positions, and subduction polarity of the Proto -Tethys and Paleo-Tethys Ocean in the WKO. The main cause of these controversies is the lack of a high-resolution lithospheric structure in this area. To clarify and gain deeper insights into the orogenic processes of Tethys, a 350-km-long Magnetotelluric (MT) profile, consisting of 32 broadband sounding stations, was deployed across the Tarim Basin (TB), Northern Kunlun Terrane (NKT), Southern Kunlun Terrane (SKT), Mazar Accretionary prism, and Karakorum Terrane (KKT) to collect field data for at least 36 h. Dimensionality analysis indicated that a 2D analysis was valid. The MT data were rotated to a 150° direction before inversion, based on an electrical principal strike analysis. The MT data were then imaged through a joint inversion of Transverse Electric Field (TE) and Transverse Magnetic Field (TM) modes using a nonlinear conjugate gradient (NLCG) algorithm. The resulting model provides crucial new constraints on the lithospheric structure beneath the WKO, revealing several distinct resistive anomalies. The bidirectional dipping geometry of these anomalies, integrated with geochronological and geochemical evidence, reveals two distinct subduction systems: one between the Northern and Southern Kunlun terranes, representing the subduction polarity of Proto-Tethys Ocean, and another between the Southern Kunlun and Karakorum terranes, recording the subduction process of Paleo-Tethys Ocean. Additionally, we interpret two resistive lower crust-uppermost mantle structures beneath the Mazar accretionary prism as a delaminated oceanic slab. Concurrently, a large, interconnected high-conductivity zone from the crust to the upper mantle is identified, likely reflecting partial melting due to asthenospheric upwelling triggered by Mid-Jurassic slab delamination. Furthermore, we propose that these pre-existing weak zones ultimately facilitated the Cenozoic deformation and uplift of the Kunlun Mountains during the ongoing India-Asia collision.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"258 ","pages":"Article 105265"},"PeriodicalIF":4.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-03-01Epub Date: 2026-01-07DOI: 10.1016/j.gloplacha.2026.105280
Hui Chen , Zhen Yan , Changlei Fu , Jonathan C. Aitchison
The Qilian Orogen in the northeastern margin of Qinghai-Tibetan plateau records the tectonic history of the Proto-Tethyan Ocean from its initial subduction to final closure. However, the timing of subduction initiation, subduction polarity, and arc-continent collision processes remain controversial. This study investigates detrital heavy mineral assemblages and geochemistry of 135 detrital chromite and garnet grains from nine sandstone samples of the Upper Ordovician Koumenzi Formation in a coastal tidal environment within the North Qilian Belt. The results reveal distinct spatial variations in mineral abundance: chromite is more prevalent in the northern samples compared to central and southern sections, while garnet abundance exhibits an inverse pattern, with the highest abundance observed in the central section. Compositional analyses reveal that the detrital chromites closely resemble those from North Qilian MOR- and forearc SSZ-type ophiolites, whereas garnets display geochemical affinities with high-pressure/low-temperature metamorphic rocks from the accretionary complex and amphibolite–granulite–facies metamorphic complex, suggesting a mixed provenance. Integrated with detrital compositions of sandstone and conglomerate, as well as a multiple flow system characterized by SEE to NEE- and NWW to W-ward currents, these data collectively support a dual source region involving both the North Qilian island arc–accretionary complex (NQIAC) and the Central Qilian Block (CQB). Based on the spatial-temporal evolution of the NQIAC and Andean-type margin of the CQB, we suggest that the Proto-Tethyan Ocean underwent bidirectional subduction between the CQB and the North Qilian island arc from ∼520 to 450 Ma, followed by a subduction polarity reversal during arc-continent collision at ∼450–440 Ma, triggering formation of a retro-foreland basin that received detritus from both the uplifted accretionary complex and the CQB.
{"title":"Late Ordovician arc-continent collision in the northernmost Tethyan-Ocean: Insights from detrital chromite and garnet geochemistry of the Koumenzi Formation in the Qilian Orogenic Belt","authors":"Hui Chen , Zhen Yan , Changlei Fu , Jonathan C. Aitchison","doi":"10.1016/j.gloplacha.2026.105280","DOIUrl":"10.1016/j.gloplacha.2026.105280","url":null,"abstract":"<div><div>The Qilian Orogen in the northeastern margin of Qinghai-Tibetan plateau records the tectonic history of the Proto-Tethyan Ocean from its initial subduction to final closure. However, the timing of subduction initiation, subduction polarity, and arc-continent collision processes remain controversial. This study investigates detrital heavy mineral assemblages and geochemistry of 135 detrital chromite and garnet grains from nine sandstone samples of the Upper Ordovician Koumenzi Formation in a coastal tidal environment within the North Qilian Belt. The results reveal distinct spatial variations in mineral abundance: chromite is more prevalent in the northern samples compared to central and southern sections, while garnet abundance exhibits an inverse pattern, with the highest abundance observed in the central section. Compositional analyses reveal that the detrital chromites closely resemble those from North Qilian MOR- and forearc SSZ-type ophiolites, whereas garnets display geochemical affinities with high-pressure/low-temperature metamorphic rocks from the accretionary complex and amphibolite–granulite–facies metamorphic complex, suggesting a mixed provenance. Integrated with detrital compositions of sandstone and conglomerate, as well as a multiple flow system characterized by SEE to NEE- and NWW to W-ward currents, these data collectively support a dual source region involving both the North Qilian island arc–accretionary complex (NQIAC) and the Central Qilian Block (CQB). Based on the spatial-temporal evolution of the NQIAC and Andean-type margin of the CQB, we suggest that the Proto-Tethyan Ocean underwent bidirectional subduction between the CQB and the North Qilian island arc from ∼520 to 450 Ma, followed by a subduction polarity reversal during arc-continent collision at ∼450–440 Ma, triggering formation of a retro-foreland basin that received detritus from both the uplifted accretionary complex and the CQB.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"258 ","pages":"Article 105280"},"PeriodicalIF":4.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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