Global and Planetary Change最新文献

{"title":"High-latitude continental evidence of the Jenkyns Event: Insights from the Southern Junggar Basin, NW China","authors":"Zhihui Zhang ,&nbsp;Yuanchen Guo ,&nbsp;Dawei Lv ,&nbsp;Man Lu ,&nbsp;Tiantian Wang ,&nbsp;Luojing Wang ,&nbsp;Guibo Zheng ,&nbsp;Yuting Zhang ,&nbsp;Bing Wang ,&nbsp;Guoqiang Duan","doi":"10.1016/j.gloplacha.2025.105007","DOIUrl":"10.1016/j.gloplacha.2025.105007","url":null,"abstract":"<div><div>The Jenkyns Event (Toarcian Oceanic Anoxic Event, T-OAE) represents a period of extreme global warming during the Early Jurassic. This study integrated geochronological, palynological, and elemental geochemical analyses on the Lower Jurassic Sangonghe Formation, a high-latitude lacustrine sequence exposed in the Honggou Section of the Junggar Basin. The results reveal a negative organic excursion in carbon isotopes, accompanied by significant enrichment in total organic carbon (TOC) within the Sangonghe mudstone. Combined with. Zircon U<img>Pb dating and age-diagnostic palynological assemblages, these findings suggest a probable correlation with the Jenkyns Event documented in both marine and terrestrial sediments. We reconstructed the climatic changes and environmental responses of the Junggar basin during the event. Elevated values of paleoclimatic proxies, including the C value and ln (Al₂O₃/Na₂O), along with an increased proportion of drought-tolerant palynomorph taxa, indicate an inland aridification occurring alongside intermittent humidity. Concurrent declines in the clastic input proxy (Ti/Al) and increases paleoproductivity proxy (Zn/Ti) suggest lake deepening and enhanced primary productivity, potentially resulting in water-column anoxia. This interpretation is supported by positive shifts in redox-sensitive indicators, including Mo_EF, U_EF, and C_org/P. Positive correlations between TOC and indicators of primary productivity and redox conditions suggest that increased primary productivity and development of anoxia jointly facilitated substantial organic carbon accumulation in high-latitude lake, making it a sink of organic carbon during the extreme thermal event. These findings provide a terrestrial evidence from high-latitude settings of climatic and environmental responses to the Jenkyns Event and offer new insights into its global significance.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"254 ","pages":"Article 105007"},"PeriodicalIF":4.0,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144841535","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}

{"title":"East-west divergence in Holocene organic carbon accumulation of Tibetan Plateau lakes: Roles of climate and organic matter sources","authors":"Tonggang Zang ,&nbsp;Xiaohuan Hou ,&nbsp;Zhe Sun ,&nbsp;Xiaoxue Gao ,&nbsp;Kejia Ji ,&nbsp;Juzhi Hou","doi":"10.1016/j.gloplacha.2025.105014","DOIUrl":"10.1016/j.gloplacha.2025.105014","url":null,"abstract":"<div><div>With the increasing prominence of carbon emissions and the intensification of global warming, the carbon cycle and carbon accumulation have drawn widespread attention. Lake carbon accumulation is a crucial component of the terrestrial carbon cycle, significantly influencing local climate change and atmospheric carbon dioxide levels. The Tibetan Plateau (TP), renowned for its high elevation, numerous alpine lakes, and large carbon storage in sediments, is a key area for studying lake organic carbon accumulation. However, the carbon accumulation rate (CAR) of lakes on the TP exhibits strong spatial variability, and the driving mechanisms vary across regions, especially in the western TP, which has been poorly studied. To understand the driving mechanisms of climate and human activities on lake CAR across the TP, we collected 33 sediment cores, including 15 from the western TP, and calculated the CAR during the Holocene. Our results show that the average CAR of lakes on the TP during the Holocene was 6.13 g C m⁻² yr⁻¹. Through relational cluster analysis, lakes were classified into two groups, with an east - west distribution pattern separated by the 90°E meridian. In eastern lakes, CAR is closely related to temperature and precipitation, while in western lakes, it is mainly influenced by wind strength. This difference is attributed to the distinct sources of organic matter in lake sediments. In eastern lakes, total organic carbon (TOC) comes from both aquatic and terrestrial plants. Higher temperatures and more precipitation promote terrestrial vegetation growth in the watershed, increasing sediment TOC content and accelerating sediment accumulation rate (SAR). In contrast, in western lakes with lower temperatures and less precipitation, TOC mainly originates from aquatic plants. Thus, temperature and precipitation changes have a minor impact on TOC, and lake sedimentation is mainly affected by wind dynamics, resulting in a negative correlation between precipitation and CAR. Additionally, the CAR of all lakes on the TP is negatively correlated with lake area and depth. Under continued warming, the CAR of eastern TP lakes is likely to increase, with small and shallow lakes playing a significant role.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"254 ","pages":"Article 105014"},"PeriodicalIF":4.0,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144828659","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}

{"title":"A strong influence of the precession and northern high latitudinal climate on the monsoon seasonality and productivity in the Andaman Sea","authors":"Rinu Fathima ,&nbsp;Rajeev Saraswat ,&nbsp;Sudhira R. Bhadra ,&nbsp;Dinesh Kumar Naik ,&nbsp;Thejasino Suokhrie","doi":"10.1016/j.gloplacha.2025.105017","DOIUrl":"10.1016/j.gloplacha.2025.105017","url":null,"abstract":"<div><div>The Indian Monsoon (IM) is a vital component of the global climate system, driving seasonal changes in precipitation, productivity, and circulation in the Indian Ocean. However, despite its significance in affecting the socio-economic conditions of over a billion people living in South Asia, the factors influencing the spatio-temporal variability of IM remain uncertain. The Andaman Sea, a core monsoon region, is a unique and relatively under-sampled basin with limited connectivity to the global ocean. To better understand the stadial-interstadial variability in IM seasonality and associated productivity, we studied the relative abundance of planktic foraminifera from the International Ocean Discovery Program (IODP) Expedition 353 Site U1448 in the Andaman Sea. Our findings reveal a strong stadial-interstadial variability in the monsoon seasonality, with a stronger Indian Summer monsoon (ISM) during the interstadials and a stronger Indian Winter monsoon (IWM) during the stadials. Specifically, the strongest ISM was during the early Holocene, associated with higher insolation, while peak IWM intensity was during the Heinrich Event 1 (H1). Moreover, we observed a strong influence of the high latitudinal millennial scale North Atlantic cold and warm events, such as Younger Dryas (YD), Heinrich Event (H1−10), and Bolling-Allerod (B/A), on the Andaman Sea, with warm events typically leading to stronger ISM and cold events leading to stronger IWM. We also report a strong coupling between ISM and productivity, with stronger ISM associated with higher productivity. A distinct stadial-interstadial variability was observed in the magnetic susceptibility (MS) and Red/Blue (R/B) reflectance ratio which were used to understand the calcium carbonate (CaCO₃) and organic carbon (C_org) content variability. The higher CaCO₃ and C_org values were observed during the interstadials and lower values during the stadials. Both, ISM and IWM exhibited a significant periodicity of 24 and 21 kyr, respectively and the summer monsoon was in phase with maximum northern hemisphere solar insolation in the precession band with a minor lag of 2.4 kyr, suggesting the dominant role of precession in controlling the monsoon in the Andaman region. This study suggests a precession modulated insolation variability as the major factor controlling IM variability, along with which, internal feedbacks including the glacial boundary conditions, northern hemisphere climate and greenhouse gas concentration also influenced the IM during the last glacial-interglacial cycle. These findings provide crucial insights into the factors affecting IM variability and will aid in improving our understanding of the climate system's complex dynamics.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"254 ","pages":"Article 105017"},"PeriodicalIF":4.0,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144864919","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}

{"title":"Variations of Zn isotopes in phosphorites and their implications","authors":"Danish Khan ,&nbsp;Haifeng Fan ,&nbsp;Hongjie Zhang ,&nbsp;Fang Zhang ,&nbsp;Eric E. Hiatt ,&nbsp;James R. Hein ,&nbsp;Ting Zhou ,&nbsp;Hanjie Wen","doi":"10.1016/j.gloplacha.2025.105016","DOIUrl":"10.1016/j.gloplacha.2025.105016","url":null,"abstract":"<div><div>Variations of Zn isotopes in phosphorites can play an important role in elucidating the primary productivity and temporal dynamics of the marine environment. However, the controlling factors associated with Zn isotope fractionation in phosphorite deposits are not well documented, which limits the utility of Zn isotope as a proxy to study modern and paleo-ocean productivity. In this research, several geochemical proxies derived from trace elements are used to monitor the effect of various parameters on the evolution of δ⁶⁶Zn in Cenozoic and Permian phosphorite deposits in detail. Lower δ⁶⁶Zn values in phosphorites indicate reduced productivity, while higher δ⁶⁶Zn values suggest increased productivity, although this relationship may be influenced by other moderating factors. The study finds that the Peru Margin (Cenozoic) and Retort Member (Permian) phosphorites exhibit lower δ⁶⁶Zn values, acting as sinks for lighter δ⁶⁶Zn. In contrast, phosphorites from the Blake Plateau align with modern deep ocean δ⁶⁶Zn values, while those from the California Borderland, Chatham Rise, and open-ocean seamounts (Cenozoic) and Meade Peak Member (Permian) show higher δ⁶⁶Zn values, serving as sinks for heavier δ⁶⁶Zn isotopes. These variations of Zn isotopes in phosphorites could be controlled by productivity and redox conditions. Based on our dataset, we suggest that in addition to organic-rich shales, Fe<img>Mn oxides, and carbonates, phosphorites may also represent another potential important sink for both lighter and heavier Zn isotopes.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"254 ","pages":"Article 105016"},"PeriodicalIF":4.0,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830643","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}

{"title":"Changes in continental weathering across the Permian-Triassic transition: A global review","authors":"Joseph Mayala Nsingi ,&nbsp;Ying Cui ,&nbsp;Emily Cepin ,&nbsp;Brian Beaty ,&nbsp;Noah Planavsky ,&nbsp;Qingting Wu ,&nbsp;Markus Adloff ,&nbsp;Jiuyuan Wang ,&nbsp;David Selby ,&nbsp;Zeyang Liu ,&nbsp;Yixin Dong ,&nbsp;Shijun Jiang ,&nbsp;Feng Zhu","doi":"10.1016/j.gloplacha.2025.105015","DOIUrl":"10.1016/j.gloplacha.2025.105015","url":null,"abstract":"<div><div>The end-Permian mass extinction (EPME) is associated with the loss of approximately 80–90 % marine species and 70 % terrestrial taxa. Massive greenhouse gas emissions from activities of the Siberian Traps Large Igneous Province (ST-LIP) and arc volcanisms are thought to be the trigger of the EPME. Global temperatures rose significantly following the EPME, and such extreme warmth persisted into the Early Triassic, which may have led to enhanced silicate weathering, and increased river runoff and sediment accumulation rate. However, ecosystem recovery was delayed by at least five million years after the EPME. One leading hypothesis attributes this protracted recovery to sustained atmospheric CO₂ accumulation, resulting from volcanic emissions from the ST-LIP that overwhelmed the normal Earth surface carbon cycle. To evaluate this, we synthesize geochemical and sedimentological records of continental weathering across the Permian–Triassic (PT) transition, drawing on a suite of proxies including major elements-based proxies, strontium (^87/86Sr and δ^88/86Sr), osmium (¹⁸⁷Os/¹⁸⁸Os), lithium (δ⁷Li), magnesium (δ²⁶Mg) and calcium (δ⁴⁴Ca) isotopes. We highlight the strengths and limitations of each proxy and assess how chemical and physical weathering may have responded to the environmental perturbations across the PT transition. Collectively, these records can help test the hypothesis that the silicate weathering feedback were insufficient to counteract elevated CO₂ levels, thereby failing to stabilize Earth's climate during the prolonged Early Triassic warmth.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"254 ","pages":"Article 105015"},"PeriodicalIF":4.0,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144864918","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}

{"title":"Chinese speleothem evidence of the early-mid Holocene transition and the instability of Asian summer monsoon","authors":"Bin Zhao ,&nbsp;Yongjin Wang ,&nbsp;Kan Zhao ,&nbsp;Jianjun Yin ,&nbsp;Quan Wang ,&nbsp;Shaohua Yang ,&nbsp;Qingfeng Shao ,&nbsp;Hai Cheng ,&nbsp;Yijia Liang","doi":"10.1016/j.gloplacha.2025.105010","DOIUrl":"10.1016/j.gloplacha.2025.105010","url":null,"abstract":"<div><div>The Asian summer monsoon circulation during the Holocene is suggested to be controlled by northern hemisphere summer insolation, but the transition from strong to weak monsoon status lagged the insolation peak, and its causes remain unclear. Here, we provide a high-resolution East Asian summer monsoon record, with 14 ²³⁰Th/U dates and 510 δ¹⁸O data on a stalagmite from Shima Cave, central China, spanning the past 14.6 ka. Our record shows a gradual monsoon intensification from the deglaciation to the early Holocene, followed by monsoon deterioration since the mid Holocene. Using 23 cave δ¹⁸O records from China, we obtained an integrated δ¹⁸O record in order to investigate the overall changes in Asian summer monsoon circulation throughout the Holocene. The general pattern and transition of the integrated δ¹⁸O record agree well with the Ti record from Cariaco Basin, both demonstrating a prominent transition at ∼7.5 ka BP and coinciding with worldwide reorganizations of atmospheric circulations. The early-mid Holocene monsoon transition demonstrates that the response of the monsoon to insolation is likely altered by internal changes, including temperature in northern hemisphere and ice-sheet recession. Besides, fluctuating monsoon climate during the early Holocene is well demonstrated in Shima record. Prominent and large-amplitude monsoon weakenings during the 8.2 ka, 9.2 ka and Preboreal Oscillation events, and five small-amplitude events, all related to meltwater injections and cooling in the North Atlantic regions. The close correspondence between these reconstructions suggests that the early Holocene monsoonal changes were sensitive to northern high-latitude climates during the process of ice sheet retreat.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"254 ","pages":"Article 105010"},"PeriodicalIF":4.0,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827328","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}

{"title":"Slab tearing controlling divergent volatile fluxes at convergent plate boundaries, southern Tibetan Plateau","authors":"Sanyu Quan ,&nbsp;Yingchun Wang ,&nbsp;Shuang Liao ,&nbsp;Yi Wang ,&nbsp;Yinlei Hao ,&nbsp;Jiao Tian ,&nbsp;Zhongping Li ,&nbsp;Chunhui Cao ,&nbsp;Hikaru Iwamori","doi":"10.1016/j.gloplacha.2025.105011","DOIUrl":"10.1016/j.gloplacha.2025.105011","url":null,"abstract":"<div><div>The morphology and characteristics of subducting slabs play a critical role in controlling the formation and release of volatiles at plate boundaries. However, this control mechanism remains unclear in orogenic belts, such as the Tibetan Plateau. This study compiles helium and carbon data from 116 hot springs (132 samples) across three rift systems in southern Tibet—Pumqu-Xianza Rift, Yadong-Gulu Rift, and Cuona-Woka Rift—and employs a revised helium‑carbon coupling model, along with Monte Carlo simulation. The results reveal a transitional zone between the previously defined helium boundary (“mantle suture”) and newly identified carbon boundary (“tear boundary”), indicating a 200-km-wide transitional zone between the pre-established helium boundary and the newly identified carbon boundary, showing northward displacement of the carbon boundary relative to the helium boundary. Calculated ³He fluxes demonstrate spatial variations: 8.8 × 10³ atoms/m²/s south of the helium boundary, 3.3 × 10⁴ atoms/m²/s within the transitional zone, and 2.1 × 10⁵ atoms/m²/s north of the carbon boundary. Slab tearing appears to between YGR and PXR (∼89°E), resulting in significant differences in mantle volatile distribution. The mantle carbon is &lt;1 % south of the helium boundary, ranges from 1 % and 2 % in the transition zone, while higher than 2 % north of the carbon boundary (with a mean of 4.6 %). V-type slab tearing west of YGR facilitates asthenospheric upwelling under ongoing north-south compression, generating E-W crustal extension that ultimately forms the rift system. These findings highlight the critical impact of slab tearing on the mantle-crust interactions, the regulation of volatile migration, and the geodynamic processes influencing habitability in the collision zone.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"254 ","pages":"Article 105011"},"PeriodicalIF":4.0,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144865042","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}

{"title":"Preface to the special issue: Western Pacific biogeochemical cycles across the air-sea and sediment-water interfaces and their response to global changes","authors":"Tianyu Chen ,&nbsp;Zhimian Cao ,&nbsp;Joseph Stewart ,&nbsp;Xianhui Wan","doi":"10.1016/j.gloplacha.2025.105013","DOIUrl":"10.1016/j.gloplacha.2025.105013","url":null,"abstract":"<div><div>The Western Pacific is a unique region for studying cross-interface biogeochemical cycling, which is influenced by the boundary currents and their interactions with the East Asian marginal seas. This special issue expands our knowledge of the Western Pacific biogeochemical cycles across the air–sea and sediment–water interfaces, and their links with global climate change. It contains 27 research articles addressing 3 primary themes: (i) air–sea interface processes (e.g., biological pump, gas exchange, dust fluxes), (ii) sediment–water interface processes (e.g., organic matter diagenesis, hydrothermal flux, metal isotope geochemistry), and (iii) paleoceanographic records documenting past Western Pacific productivity, carbon cycle and water mass mixing. Together, these contributions advance our understanding of how the Western Pacific Ocean participates in global biogeochemical and climate systems, both in the present and geological past.</div></div>","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"254 ","pages":"Article 105013"},"PeriodicalIF":4.0,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144897863","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}

{"title":"Establishing a robust area-to-volume scaling for Qinghai-Tibetan Plateau Retrogressive Thaw Slumps: A key tool for quantifying mass wasting and carbon release induced by permafrost degradation","authors":"Jiapei Ma, Genxu Wang, Chunlin Song, Dexin Gao, Jinlong Li, Peng Huang, Linmao Guo, Kai Li, Shan Lin, Shouqin Sun","doi":"10.1016/j.gloplacha.2025.105012","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2025.105012","url":null,"abstract":"Quantifying soil erosion and associated carbon release from Retrogressive Thaw Slumps (RTSs) across the vast Qinghai-Tibetan Plateau (QTP) remains challenging due to the difficulty in obtaining large-scale volumetric data. This knowledge gap hinders accurate assessments of permafrost degradation impacts. Here, we developed a regionally specific area-to-volume scaling relationship using multi-source high-resolution Digital Elevation Model (DEM) data. Based on the regression of 1,443 slumps, we found that RTS volume (V) scales with area (A) following the power law <mml:math altimg=\"si4.svg\"><mml:mi>V</mml:mi><mml:mo>=</mml:mo><mml:mfenced close=\")\" open=\"(\"><mml:mrow><mml:mn>0.18</mml:mn><mml:mo>±</mml:mo><mml:mn>0.04</mml:mn></mml:mrow></mml:mfenced><mml:mo>·</mml:mo><mml:msup><mml:mi>A</mml:mi><mml:mrow><mml:mn>1.20</mml:mn><mml:mo>±</mml:mo><mml:mn>0.02</mml:mn></mml:mrow></mml:msup><mml:mo>,</mml:mo><mml:mfenced close=\")\" open=\"(\" separators=\",\"><mml:mrow><mml:msup><mml:mi>R</mml:mi><mml:mn>2</mml:mn></mml:msup><mml:mo>=</mml:mo><mml:mn>0.88</mml:mn></mml:mrow><mml:mrow><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.001</mml:mn></mml:mrow></mml:mfenced></mml:math>. This distinct scaling relationship reflects the relatively smaller area and shallower slump floor depth of RTSs on the QTP compared to those in Arctic regions. By integrating this scaling with an estimation model accounting for RTS geometry and the spatial heterogeneity of soil and ground-ice content, we reconstructed RTS volumetric changes (1989–2022), revealing a total mass wasting of 0.87 × 10<ce:sup loc=\"post\">8</ce:sup> t (95 % CI: 0.54× 10<ce:sup loc=\"post\">8</ce:sup>–1.44× 10<ce:sup loc=\"post\">8</ce:sup> t) in the past 3 decades. Associated carbon release peaked at 0.16 <mml:math altimg=\"si5.svg\"><mml:mi mathvariant=\"italic\">Tg</mml:mi><mml:mo>·</mml:mo><mml:mi>C</mml:mi><mml:mo>·</mml:mo><mml:mi>y</mml:mi><mml:msup><mml:mi>r</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math> (95 % CI: 0.13–0.20 <mml:math altimg=\"si5.svg\"><mml:mi mathvariant=\"italic\">Tg</mml:mi><mml:mo>·</mml:mo><mml:mi>C</mml:mi><mml:mo>·</mml:mo><mml:mi>y</mml:mi><mml:msup><mml:mi>r</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math>) in 2016, offsetting ∼3.1 % of the total permafrost carbon sink. Although current impacts remain moderate, the observed non-linear response of RTS activity to warming and wetting—where ∼20 % higher temperatures and 12 % more precipitation in summer months have driven nearly a tenfold increase in activity—suggests future risks could escalate. Our findings close a critical gap in RTS volume monitoring across the QTP and provide a quantitative framework for evaluating permafrost degradation and its carbon feedback under a warming climate.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"42 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144897864","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}

{"title":"Ni-Mo isotopes track marine metal cycling through early Cambrian redox shifts: Metalliferous black shales as paleo-environmental archives","authors":"Liu Willow Yang, Tao Yang, Huiyang Yu, Tao Han, Jian-Feng Gao, Hong-Fei Ling","doi":"10.1016/j.gloplacha.2025.105008","DOIUrl":"https://doi.org/10.1016/j.gloplacha.2025.105008","url":null,"abstract":"Highly metalliferous black shales, enriched in trace metals like nickel and molybdenum, are valuable archives for reconstructing ancient marine environment and metal cycling. Despite various metallogenic models, the mechanisms driving Ni<ce:glyph name=\"sbnd\"></ce:glyph>Mo mineralization remain unclear, with limited attention to continuous stratigraphic profiles and environmental context. To address this, we apply the coupled δ<ce:sup loc=\"post\">98</ce:sup>Mo-δ<ce:sup loc=\"post\">60</ce:sup>Ni isotopic approach, along with multi-proxy geochemical data, to a continuous early Cambrian section (Songlin section) and compares with three other Ni-Mo-enriched deposits across South China (Zunyi, Nayong and Zhangjiajie). δ<ce:sup loc=\"post\">98</ce:sup>Mo values range from −0.3 ‰ to +2.1 ‰ and δ<ce:sup loc=\"post\">60</ce:sup>Ni from −0.4 ‰ to +0.8 ‰, with a strong positive correlation (R<ce:sup loc=\"post\">2</ce:sup> = 0.51). Consistent trend between ore layers and host rocks suggests co-fractionation of Mo and Ni isotopes through adsorption onto Fe<ce:glyph name=\"sbnd\"></ce:glyph>Mn (hydro)oxides. Stratigraphic trends suggest a three-stage paleoenvironmental evolution, with intensified euxinia and upwelling during Member II deposition favoring Ni<ce:glyph name=\"sbnd\"></ce:glyph>Mo precipitation. While euxinia and organic matter burial contributed to metal retention in the sediments, these factors alone cannot fully explain the isotope variations. We propose that redox-sensitive Fe<ce:glyph name=\"sbnd\"></ce:glyph>Mn (hydro)oxide cycling, modulated by variable redox, upwelling and primary productivity conditions, serves as the primary control on the metal accumulation. Comparable isotopic patterns in other metalliferous shales along the earth's history suggest a common mechanism during global redox transitions. This study underscores the potential of coupled δ<ce:sup loc=\"post\">98</ce:sup>Mo-δ<ce:sup loc=\"post\">60</ce:sup>Ni as powerful tracers for marine metal cycling and paleoredox reconstruction, offering new insights into the role of ocean chemistry in metal deposition during key redox transitions in the Earth's past.","PeriodicalId":55089,"journal":{"name":"Global and Planetary Change","volume":"115 1","pages":"105008"},"PeriodicalIF":3.9,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144901608","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}