Journal of Asian Earth Sciences最新文献_第2页

In-situ U-Pb ages of calcite from the Nadan Sb deposit (South China) record a ∼ 10 million years lifecycle of the hydrothermal system 华南纳丹Sb矿床方解石的原位U-Pb年龄记录了热液系统的生命周期约1000万年

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-04-01 Epub Date: 2026-01-30 DOI: 10.1016/j.jseaes.2026.106985

Ni Peng , Dai Zhang , Alexandre Cugerone , Kai Luo , Jia-Xi Zhou

{"title":"In-situ U-Pb ages of calcite from the Nadan Sb deposit (South China) record a ∼ 10 million years lifecycle of the hydrothermal system","authors":"Ni Peng , Dai Zhang , Alexandre Cugerone , Kai Luo , Jia-Xi Zhou","doi":"10.1016/j.jseaes.2026.106985","DOIUrl":"10.1016/j.jseaes.2026.106985","url":null,"abstract":"<div><div>The duration of hydrothermal activity is key to understanding the genesis of hydrothermal deposits, yet dating low-temperature systems is difficult due to the scarcity of suitable minerals. The Youjiang Basin in the western South China Antimony Metallogenic Belt (SCAMB) hosts several giant Sb deposits and represents the largest low-temperature (<250 °C) Au-As-Sb-Hg mineralization domain in China. Although previous studies have reported mineralization ages of 148–101 Ma for regional Sb deposits, the duration of hydrothermal activity for a single deposit remains unclear. The Nadan Sb deposit in the southwestern Youjiang Basin contains three generations of stibnite-associated calcite (Cal-I, II, III), providing an ideal case for investigation. LA-ICPMS analyses show decreasing Fe-Mn contents (5330–3760, 3291–1537, and 1764–566 ppm) and increasing total REE concentrations (1.57, 10.7, and 12.1 ppm) from Cal-I to Cal-III. U-Pb dating yields ages of 81.6 ± 1.7 Ma, 77.6 ± 1.1 Ma, and 69.8 ± 1.7 Ma, suggesting that the Nadan deposit is the youngest Sb deposit in the SCAMB. The ∼ 10 Myr age span indicates prolonged hydrothermal activity. δ<sup>13</sup>C<sub>PDB</sub> (−0.10‰ to + 0.75‰) and δ<sup>18</sup>O<sub>SMOW</sub> (+10.71‰ to + 12.72‰) values suggest calcite precipitation from magmatic-hydrothermal fluids. These results indicate that sustained magmatic heat and fluid input enabled the long-lived hydrothermal system and played a key role in Sb mineralization in the SCAMB.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"300 ","pages":"Article 106985"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mini-batch-based joint inversion of surface wave dispersion and gravity anomaly for high-resolution crustal velocity structure of China and its adjacent regions 中国及邻区高分辨率地壳速度结构面波频散与重力异常联合小批反演

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-04-01 Epub Date: 2026-01-30 DOI: 10.1016/j.jseaes.2026.106983

Aolin Xiong , Jiangtao Li , Yudi Pan , Hanbing Ai

{"title":"Mini-batch-based joint inversion of surface wave dispersion and gravity anomaly for high-resolution crustal velocity structure of China and its adjacent regions","authors":"Aolin Xiong , Jiangtao Li , Yudi Pan , Hanbing Ai","doi":"10.1016/j.jseaes.2026.106983","DOIUrl":"10.1016/j.jseaes.2026.106983","url":null,"abstract":"<div><div>High-resolution crustal velocity models are essential for understanding the tectonic evolution of China and its adjacent regions, while inversion based solely on an individual geophysical dataset inherently suffers from uncertainty and limited resolution. To mitigate these limitations, we propose a mini-batch-based joint inversion method that integrates surface wave dispersion and gravity anomaly, and apply it to achieve high-resolution crustal shear-wave velocity structure beneath China and its adjacent regions. We improve the joint inversion framework by <span><span>Du et al. (2021)</span></span> through randomly partitioning the surface wave dispersion data into mini-batches, to overcome computation and memory issues with large dataset. Besides, to enhance the sensitivity and constraints of Bouguer gravity anomaly on crustal and uppermost mantle structures, we apply a spherical harmonic expansion to remove long-wavelength background signals. The proposed mini-batch strategy ensures stochastic utilization of the full dataset, significantly reduces computational costs, accelerates convergence, and improves resistance to noise interference. The joint inversion results exhibit apparent improvements in structural resolution, allowing for clearer delineation of segmented low-velocity zones across the Tibetan Plateau, relatively high-velocity anomalies beneath the Lhasa and southern Qiangtang Terrane, stable cratonic features beneath the Sichuan and Tarim Basin, and low-velocity anomalies beneath the Qilian, Changbai and Taiwan orogenic belts. The results also provide refined constraints on the geometry and depth of the Moho interface, demonstrating high sensitivity to complex tectonic regions. These findings provide important constraints on regional tectonic mechanisms. The proposed joint inversion method holds broad application potential in large-scale, massive-data geophysical imaging.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"300 ","pages":"Article 106983"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sphalerite trace-element and S–Cd isotopic compositions revealing the skarn Zn–Pb mineralization processes in southern hunan province, southeastern china 闪锌矿微量元素和S-Cd同位素组成揭示了湘南矽卡岩型锌-铅成矿过程

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-04-01 Epub Date: 2026-01-24 DOI: 10.1016/j.jseaes.2026.106979

Teng Ding , Luyu Cai , Chuanwei Zhu , Rongqing Zhang , Tao Yang , Xudong Huang , Jin Liang

{"title":"Sphalerite trace-element and S–Cd isotopic compositions revealing the skarn Zn–Pb mineralization processes in southern hunan province, southeastern china","authors":"Teng Ding , Luyu Cai , Chuanwei Zhu , Rongqing Zhang , Tao Yang , Xudong Huang , Jin Liang","doi":"10.1016/j.jseaes.2026.106979","DOIUrl":"10.1016/j.jseaes.2026.106979","url":null,"abstract":"<div><div>In this study, we analyzed trace-element and S–Cd isotopic compositions of sphalerite and related igneous rocks from four representative skarn deposits in southern Hunan Province, southeastern China. These include the Shuikoushan (SKS), Tongshanling (TSL), and Baoshan (BS) Zn–Pb(–Cu) deposits associated with granodiorite porphyry, and the Huangshaping (HSP) Zn–Pb–W deposit related to granite porphyry. Our results indicate that sphalerite from the SKS deposit exhibits consistent <em>δ</em><sup>114/110</sup>Cd and δ<sup>34</sup>S values near 0 ‰, with Zn/Cd ratios resembling those of typical high-temperature mineralization systems. In contrast, sphalerite from the BS and TSL deposits shows lower <em>δ</em><sup>114/110</sup>Cd and Zn/Cd ratios but higher δ<sup>34</sup>S values, suggesting that although the granodiorite porphyry was the primary source of Zn–Pb mineralization in these three deposits, the carbonate strata contributed additional sulfur and metals to the BS and TSL systems. Meanwhile, sphalerite from the HSP deposit is characterized by elevated <em>δ</em><sup>114/110</sup>Cd, δ<sup>34</sup>S, and Zn/Cd ratios, implying that hydrothermal circulation through basement rocks played a dominant role in metal and sulfur extraction, with evaporite layers providing heavy sulfur. Integrating these findings with previous petrological data, we propose that lower crustal melting alone was sufficient to generate Zn–Pb mineralization. Additional contributions from dehydrated and melted subducted slabs, together with upper crustal melting, further led to the superposition of Cu and W–Sn mineralization in southern Hunan Province.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"300 ","pages":"Article 106979"},"PeriodicalIF":2.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effective application of multidimensional scaling for detrital zircon geochronology in the southern Miryang Subbasin, Gyeongsang Basin, Korea 多维标度在庆尚盆地密阳次盆地南部碎屑锆石年代学中的有效应用

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-03-15 Epub Date: 2026-01-05 DOI: 10.1016/j.jseaes.2026.106954

Yong-Un Chae , Taejin Choi , Young Ji Joo , Kyung Soo Kim , Sujin Ha , Hyoun Soo Lim

{"title":"Effective application of multidimensional scaling for detrital zircon geochronology in the southern Miryang Subbasin, Gyeongsang Basin, Korea","authors":"Yong-Un Chae , Taejin Choi , Young Ji Joo , Kyung Soo Kim , Sujin Ha , Hyoun Soo Lim","doi":"10.1016/j.jseaes.2026.106954","DOIUrl":"10.1016/j.jseaes.2026.106954","url":null,"abstract":"<div><div>Zircon U-Pb dating was conducted using laser ablation multi-collector inductively coupled plasma mass spectrometry on samples collected from five Natural Monument fossil sites in the southern Miryang Subbasin of the Gyeongsang Basin, Korea. The resulting depositional ages and ages of fossil occurrence are approximately 117 Ma (Aptian) and 113 Ma (Aptian–Albian boundary) in the Hasandong Formation, 104 Ma (Albian) and 96 Ma (Cenomanian) in the Haman Formation, and 93 Ma (Turonian) in the Jindong Formation. By synthesizing the detrital zircon age distributions from this and previous studies, we identify distinct temporal changes in provenance that are more dynamic in the southern subbasin than in its central and northern regions. However, conventional multidimensional scaling (MDS) approaches, which rely on all concordant zircon ages, often obscure provenance signals in volcanic-arc settings due to the dominance of syndepositional volcanic zircons and widely distributed Paleoproterozoic basement rocks. To address this limitation, we applied a geologically informed filtering protocol that removes near-syndepositional volcanic ages (<145 Ma) and non-diagnostic Paleoproterozoic components (>1600 Ma), which commonly mask provenance-sensitive age populations. This refinement focuses on the 1600–145 Ma interval, enhancing the clarity and geological coherence of the resulting MDS configurations. Applying this approach to the Miryang Subbasin dataset improves the separation of samples and reveals diagnostic age patterns consistent with independent geological evidence. Our findings provide refined depositional age constraints and provenance interpretations for the southern Miryang Subbasin and demonstrate a practical framework for enhancing MDS performance in sedimentary basins influenced by syndepositional volcanism.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"299 ","pages":"Article 106954"},"PeriodicalIF":2.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multiscale pore structure and coalbed methane in the Jurassic deep coal seams of Southern Junggar Basin, China 准噶尔盆地南部侏罗系深部煤层多尺度孔隙结构与煤层气

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-03-15 Epub Date: 2026-01-06 DOI: 10.1016/j.jseaes.2026.106955

Zhonghong Chen , Kegong Dong , Weijiang Yao , Xin Hu , Xiaojie Jin , Xu Ou

{"title":"Multiscale pore structure and coalbed methane in the Jurassic deep coal seams of Southern Junggar Basin, China","authors":"Zhonghong Chen , Kegong Dong , Weijiang Yao , Xin Hu , Xiaojie Jin , Xu Ou","doi":"10.1016/j.jseaes.2026.106955","DOIUrl":"10.1016/j.jseaes.2026.106955","url":null,"abstract":"<div><div>This study addresses key scientific challenges regarding reservoir space in deep coal reservoirs (>2400 m). The multi-scale pore structure in coal rocks, as well as the occurrence state of CBM governed by this structure, such as the proportional fractions of adsorbed gas and free gas, plays a crucial role in comprehending the permeability and adsorption capacity of deep coal rocks. The pore structure and gas content of Jurassic Xishanyao Formation (J<sub>2</sub><em>x</em>) coal seams (2460–2585 m) in the central southern Junggar Basin were investigated using multiscale experimental techniques, including FE-SEM, micro-computed tomography (μ-CT), high-pressure mercury intrusion porosimetry (MIP), low-temperature N<sub>2</sub>/CO<sub>2</sub> physisorption, nuclear magnetic resonance (NMR), and isothermal adsorption experiments. Results indicate that the full-scale pore structure is dominated by macropores (>50 nm, avg. 67.7 % of pore volume), followed by micropores (<2 nm, avg. 27.9 %). Critically, micropores contribute 96.43 % of the specific surface area, serving as the primary reservoir for adsorbed gas. Confining pressure (3.45–35 MPa) significantly degrades reservoir quality, causing 23.2 %–63.5 % porosity loss and 97.5 %–99.4 % permeability decline. Deep coals host both adsorbed and free gas. Adsorbed gas content (4.63–10.09 cm<sup>3</sup>/g) is controlled by micropore volume and specific surface area, while free gas content (6.16–8.04 cm<sup>3</sup>/g) correlates positively with macropore volume and constitutes a proportion of 44.8 % in average, significantly exceeding levels in shallow CBM reservoirs. Effective porosity (avg. 2.06 %) provided by macropores (including micro-fractures) forms the storage space for free gas. The results provide a crucial theoretical foundation for evaluating deep CBM reservoirs.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"299 ","pages":"Article 106955"},"PeriodicalIF":2.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Early Permian deltaic systems and weathering differentiation in the southwestern Yangtze Block, South China: Constraints from detrital zircon geochronology and paleogeography reconstruction 扬子地块西南部早二叠世三角洲体系与风化分异：碎屑锆石年代学和古地理重建的约束

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-03-15 Epub Date: 2026-01-12 DOI: 10.1016/j.jseaes.2026.106970

Xusheng Deng , Jintao Zhou , Wenchao Yu , Yuansheng Du , Shengyuan Ji , Ruiqin Lin

{"title":"Early Permian deltaic systems and weathering differentiation in the southwestern Yangtze Block, South China: Constraints from detrital zircon geochronology and paleogeography reconstruction","authors":"Xusheng Deng , Jintao Zhou , Wenchao Yu , Yuansheng Du , Shengyuan Ji , Ruiqin Lin","doi":"10.1016/j.jseaes.2026.106970","DOIUrl":"10.1016/j.jseaes.2026.106970","url":null,"abstract":"<div><div>During the glacial maximum of the Late Paleozoic Ice Age (Asselian–Sakmarian), the Yangtze Block of South China was under the humid climate and located in equatorial eastern Paleo-Tethys. The sedimentary records in the Yangtze Block include intense weathering-related bauxites which are well known, but coeval normal clastic sedimentary rocks, such as those of the Longyin and Baomoshan formations, are poorly studied. In particular, sedimentological and provenance studies of these formations are not available, hindering a comprehensive understanding of Early Permian paleogeography, source to sink system, and weathering patterns in the Yangtze Block. Here, this study combines detrital zircon geochronology with sedimentological analysis of Early Permian clastic sedimentary rocks in the southwestern Yangtze Block. The clastic rocks of the Longyin and Baomoshan formations contain detrital zircon grains with three major age groups (500–650, 750–850, and 900–1000 Ma). These ages are clearly indicative of multiple sources including the dominant provenance from the Lower Ordovician strata in the Kangdian Uplift (western Yangtze Block). The sedimentary records and paleogeographic reconstruction show two eastward-prograding deltaic systems during the Early Permian. An Early Artinskian relative sea-level fall is recorded across the Yangtze Block, synchronous with global glacio-eustatic decline. This eustatic decline reflects Early Permian glaciations on Gondwana. Moreover, the results show that topographic gradient controls the spatial distribution of bauxite versus clastic deposits by governing the equilibrium between chemical weathering and sediment supply, providing a predictive template for bauxite exploration in other glaciation-influenced low-latitude settings.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"299 ","pages":"Article 106970"},"PeriodicalIF":2.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Distribution and enrichment characteristics of carbonate-hosted clay-type lithium resources in western Guangxi, South China 桂西碳酸盐岩粘土型锂资源分布及富集特征

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-03-15 Epub Date: 2026-01-03 DOI: 10.1016/j.jseaes.2026.106948

Jiarong Li , Yazhou Fu , Jiafei Xiao , Huawen Qi , Jiantang Peng , Jian Zhang

{"title":"Distribution and enrichment characteristics of carbonate-hosted clay-type lithium resources in western Guangxi, South China","authors":"Jiarong Li , Yazhou Fu , Jiafei Xiao , Huawen Qi , Jiantang Peng , Jian Zhang","doi":"10.1016/j.jseaes.2026.106948","DOIUrl":"10.1016/j.jseaes.2026.106948","url":null,"abstract":"<div><div>Carbonate-hosted clay-type lithium deposits represent a newly recognized lithium resource in China. This study integrates field observations, mineralogical and geochemical analyses from 267 samples collected across 18 stratigraphic sections of the Upper Permian Heshan Formation in western Guangxi, to investigate the distribution and enrichment of lithium. Results reveal significant spatial heterogeneity, with the Pingguo area exhibiting the highest Li enrichment (averaging 3157 ppm in carbonaceous mudstone), while other regions such as Jingxi, Tianyang, and Dahua display only moderate or localized enrichment. Lithium concentration is strongly lithology-dependent: carbonaceous mudstone contains the highest Li, followed by aluminous mudstone and bauxitic rock, whereas ferruginous mudstone and bauxite are largely barren. Cookeite is the primary Li carrier, showing a strong correlation with whole-rock Li (R<sup>2</sup> = 0.84). We propose that Li-rich kaolinite precipitated from weathering solutions at the karstic unconformity and recrystallized into cookeite during shallow burial diagenesis. Lithium can also occur in clay minerals via isomorphism or adsorption, and organic matter may contribute to enrichment. Geochemical indices (Rb/K, Ni/Co, Sr/Cu, La/Y) indicate deposition under oxidizing, marine-continental transitional, hot-arid, and weakly acidic conditions, favoring Li adsorption and retention. Immobile element and REE signatures suggest detrital materials were mainly derived from peralkaline-peraluminous felsic rocks of the Permian Emeishan large igneous province and a coeval magmatic arc. This work advances the understanding of non-conventional lithium resources in South China and positions western Guangxi as a strategic Li supply base for China’s low-carbon economy.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"299 ","pages":"Article 106948"},"PeriodicalIF":2.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145908874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Paleo-Pacific slab break-off revealed by Cretaceous I-type and peralkaline A-type granite associations in the Cathaysia Block, SE China 华夏地块白垩系i型和过碱性a型花岗岩组合揭示的古太平洋板块断裂

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-03-15 Epub Date: 2026-01-04 DOI: 10.1016/j.jseaes.2026.106949

Ao Li , Wu-Bin Yang , Ning-Bo Li , Shuo Xue , He-Cai Niu , Qiang Shan

{"title":"Paleo-Pacific slab break-off revealed by Cretaceous I-type and peralkaline A-type granite associations in the Cathaysia Block, SE China","authors":"Ao Li , Wu-Bin Yang , Ning-Bo Li , Shuo Xue , He-Cai Niu , Qiang Shan","doi":"10.1016/j.jseaes.2026.106949","DOIUrl":"10.1016/j.jseaes.2026.106949","url":null,"abstract":"<div><div>Investigating spatially and temporally associated granites can provide significant constraints on regional crustal reworking and geodynamic evolution. A famous instance is the coexistence of Cretaceous I-type and peralkaline A-type granites along the coastal Cathaysia Block; nevertheless, their origins and genetic connections remain controversial. Here, we employed zircon U-Pb-Hf-O isotopes, alongside whole-rock geochemistry and Nd-Hf isotopes, to examine the Qingtian granite association within the Cathaysia Block. Zircon U-Pb dating yields crystallization ages of 106.0 ± 0.5 Ma for the I-type granite and 95.8 ± 0.8 Ma for the peralkaline A-type granite, indicating an ∼10 Myr gap. The I-type granite has variable zircon ε<sub>Hf</sub>(t) values (–15.8 to –4.50) and mantle-like δ<sup>18</sup>O (4.76–5.91 ‰), demonstrating a hybrid source comprising Mesozoic juvenile mafic lower continental crust (LCC) and Mesoproterozoic-Paleozoic mafic LCC. In contrast, the peralkaline A-type granite displays zircon ε<sub>Hf</sub>(t) values of –7.18 to 2.07 and sub-normal mantle δ<sup>18</sup>O (4.27–5.22 ‰), together with relatively depleted Nd-Hf isotopes, elevated whole-rock zircon saturation temperatures, and enriched high-field-strength and heavy-rare-earth elements, suggesting a source generated by mixing refractory granulite residues remaining after the I-type melt extraction with melts/fluids released by high-temperature altered oceanic crust (AOC). Combined with regionally coeval oceanic island-like basalts, such AOC-derived component potentially originated from the melting/dehydration of altered gabbroic lower oceanic crust along fractured surfaces. Accordingly, we propose that paleo-Pacific slab break-off represents the likely mechanism for generating this peralkaline A-type magmatism. A compilation of Cretaceous granitoids from the Cathaysia Block further indicates that this break-off occurred at ∼96 Ma.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"299 ","pages":"Article 106949"},"PeriodicalIF":2.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145908885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Factors controlling the formation of high-Cr podiform chromite deposits 高铬足状铬铁矿床形成的控制因素

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-03-15 Epub Date: 2026-01-06 DOI: 10.1016/j.jseaes.2026.106958

Haitao Ma, Jingsui Yang, Pengjie Cai

{"title":"Factors controlling the formation of high-Cr podiform chromite deposits","authors":"Haitao Ma, Jingsui Yang, Pengjie Cai","doi":"10.1016/j.jseaes.2026.106958","DOIUrl":"10.1016/j.jseaes.2026.106958","url":null,"abstract":"<div><div>Understanding the genesis of podiform chromite deposits in ophiolitic mantle provides important insights into the evolution of oceanic lithospheric mantle. The melt-rock interaction between boninitic melt and mantle harzburgites is widely used to explain the genesis of high-Cr podiform chromite deposits. Nevertheless, more quantitative work is still lacking. In this study, we carried out detailed petrological and mineralogical work on the chromitite ores and host rocks from the Luobusa ophiolite, and carried out systematic thermodynamic modelling work to evaluate the factors that may affect the formation of high-Cr podiform chromite deposits. The chromitite ores consist of massive chromitites and disseminated chromitites, whose chromites exhibit high Cr values of 78.1–79.1 and 77.3–78.9, respectively. The host rocks include dunite envelopes and harzburgites, whose chromites show Cr values of 64.2–77.1 and 42.5–53.1, respectively. The parental magma of chromitite ores, calculated by chromite major and trace element data, shows a strong affinity with boninitic melts. Thermodynamic modelling results declare that the refractory degree of harzburgite is the primary factor controlling the enrichment of Cr elements in chromites. Additionally, a low melt-rock ratio, low pressure, and moderate water content in boninitic melt all promote the enrichment of Cr content in chromite. The chromitite ores and dunites from the Luobusa crust-mantle transition zone in this study are generated from the interaction process of the hydrous (water contents = 3–5 wt%) low-Ca boninitic melt and refractory harzburgites under the condition of low melt-rock ratios (1:100 to 1:20) and lower pressure (1.0 GPa).</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"299 ","pages":"Article 106958"},"PeriodicalIF":2.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impacts of climate and tectonics on orbital-scale sedimentary cycles in the Bohai Bay Basin since the late Pliocene 渤海湾盆地晚上新世以来气候和构造对轨道尺度沉积旋回的影响

IF 2.4 3区地球科学

Journal of Asian Earth Sciences Pub Date : 2026-03-15 Epub Date: 2026-01-03 DOI: 10.1016/j.jseaes.2026.106952

Yao Wang , Qinmian Xu , Wenchao Niu , Huayu Lu , Hengzhi Lyu , Enlou Zhang , Xianyan Wang

{"title":"Impacts of climate and tectonics on orbital-scale sedimentary cycles in the Bohai Bay Basin since the late Pliocene","authors":"Yao Wang , Qinmian Xu , Wenchao Niu , Huayu Lu , Hengzhi Lyu , Enlou Zhang , Xianyan Wang","doi":"10.1016/j.jseaes.2026.106952","DOIUrl":"10.1016/j.jseaes.2026.106952","url":null,"abstract":"<div><div>The ambiguous high-frequency precession cycles preserved in sediments, which are ascribed to tectonic and post-depositional disturbances, have prevented a comprehensive understanding of the direct response of the surface system to regional climate changes. To address this gap, this study investigates a well-preserved fluvial-lacustrine sequence drilled from the western region of the subsiding Bohai Bay Basin. Through high-resolution paleomagnetic dating and wavelet analysis of gamma ray data, we evaluate the impacts of regional subsidence and monsoon climate change on sedimentary cyclicities. The results reveal significant sedimentary cyclicities that respond to precession (∼21 kyr), obliquity (∼41 kyr), and eccentricity (∼100 kyr, ∼200 kyr, and ∼400 kyr) forcings since the late Pliocene. The continuous precession and obliquity signals, with their comparable variance contributions, directly demonstrate the combined influences of high-latitude ice-volume and low-latitude insolation forcings on the monsoon climatic variations. Basin subsidence and adequate sediment supply have an important impact on the preservation of high-frequency signals, resulting in higher amplitudes of precession oscillations during ∼3.5–3.3 Ma and after ∼2 Ma. In addition, the intensified ∼100 kyr sedimentary cycles are proposed to originate from the bundling of several precession or obliquity cycles, which correlates with the development of fluvial layers under changing environmental conditions. The new record provides new insights into the interactive effects of tectonic processes and climatic changes on orbital-scale sedimentary cycles in this region.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"299 ","pages":"Article 106952"},"PeriodicalIF":2.4,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145908886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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