Journal of Asian Earth Sciences最新文献_第10页

Status and prospect of hydrocarbon resources in Southeast Asian petroliferous basins 东南亚含油气盆地油气资源现状与展望

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-09 DOI: 10.1016/j.jseaes.2025.106869

Weilin Zhu , Zengyuan Zhou , Hefeng Sun , Wenxu Peng , Shijie Zhao , Xiaowei Fu , Kailong Feng

Southeast Asia (SEA) has broad prospects for cooperation in the Belt and Road Initiative. The potential of hydrocarbon resources in SEA is discussed by analyzing the basin types, resource endowment differences, and controlling factors of hydrocarbon distribution, along with the recent progress of oil and gas exploration. The results show that convergent continental margin, divergent continental margin, and Continental interior basins in SEA are formed by unidirectional drift, convergence and collision of the Tethys tectonic domain, and hydrocarbon reserves account for 34.24 %, 38.94 % and 26.83 %. Basin type, source rock type and maturity, late structuration, and oil and gas type are the main factors controlling hydrocarbon enrichment. In the past ten years, the total recoverable hydrocarbon reserves discovered in SEA were approximately 1.54 × 10⁵ mmboe, accounting for 4.8 % of the total reserves discovered in the same period. The newly discovered reserves are characterized by more gas and less oil, with natural gas accounting for 93.2 %, and the areal extent scale of the individual reservoirs is small. The exploration campaign, characterized by a low commercial success rate (10.9 %) and modest average recoverable reserves (16.01 Mmboe per discovery), demonstrated that the stratigraphic trap play concept did not meet expectations. The recoverable resources of hydrocarbons to be discovered in the main basins of SEA are approximately 3.15 × 10⁴ mmboe and 5.07 × 10⁴ mmboe, respectively. The new field of mature basins is the leading force for exploration and reserve increases. The undiscovered hydrocarbon resources are mainly distributed in these areas, especially in the deep-water areas of mature basins.

东南亚地区“一带一路”合作前景广阔。结合近年来的油气勘探进展，从盆地类型、资源禀赋差异、油气分布控制因素等方面分析了东南亚地区油气资源潜力。结果表明：东中国海的辐合型大陆边缘、扩张型大陆边缘和大陆内部盆地是由特提斯构造域的单向漂移、辐合和碰撞形成的，油气储量占比分别为34.24%、38.94%和26.83%。盆地类型、烃源岩类型及成熟度、晚期构造和油气类型是控制油气富集的主要因素。近十年来，东南亚地区发现的可采油气总储量约为1.54 × 105 mmboe，占同期发现总储量的4.8%。新发现储量具有气多油少的特点，天然气占93.2%，单个储层面积规模较小。此次勘探活动的特点是商业成功率低（10.9%），平均可采储量适中（每次发现16.01万桶油当量），表明地层圈闭油气藏的概念没有达到预期。SEA主要盆地待发现油气可采资源量分别约为3.15 × 104 mmboe和5.07 × 104 mmboe。成熟盆地的新领域是勘探增产的主导力量。未发现油气资源主要分布在这些地区，尤其是成熟盆地的深水区。

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引用次数: 0

Growth of thrust-faults in fold-and-thrust belts: an example from the Kelasu structural belt of the Kuqa depression, Tarim Basin, NW China 褶皱冲断带逆冲断层发育——以塔里木盆地库车坳陷克拉苏构造带为例

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-07 DOI: 10.1016/j.jseaes.2025.106870

Zihan Gao , Hongwei Yin , Chao Wu , Weili Chen , Jiaqi Zhao , Wanhui He , Wei Wang

The growth of thrust-faults provides critical insights into the tectonic evolution and evolution of hydrocarbon traps in fold-and-thrust belts. However, systematic analyses of the displacement profiles of faults in fold-and-thrust belts remain a great challenge because they require abundant seismic data. This study focuses on the sub-salt thrust system in the Kuqa Depression of the Tarim Basin, China, where six main thrust faults are interpreted to analyze the along-strike variations in fault displacement. The results reveal that the displacement profiles of the main thrusts exhibited significant variability in shape, peak values, and maximum displacement to fault length ratio. The growth of the sub-salt faults is controlled by the uplifted basement and the overlying salt. The basement uplift constrained the lateral propagation of the faults, and the paleo-uplift results in strike differences in the structural evolution of the fault system. In addition, large fault displacements are closely linked to thick overlying salt layers, highlighting the mechanical role of salt in facilitating displacement accumulation. These findings provide a better understanding of the growth patterns of thrust faults and their influencing factors.

逆冲断层的发育为研究褶皱冲断带构造演化和油气圈闭演化提供了重要依据。然而，由于需要大量的地震资料，对褶皱冲断带断层位移剖面的系统分析仍然是一个巨大的挑战。以塔里木盆地库车坳陷盐下逆冲系统为研究对象，对库车坳陷盐下逆冲系统的6条主要逆冲断层进行了解释，分析了断层位移的沿向变化规律。结果表明，主要逆冲断层的位移剖面在形状、峰值和最大位移与断层长度之比上表现出明显的变异性。盐下断裂的发育受抬升基底和上覆盐的控制。基底隆升制约了断裂的横向扩展，古隆升导致了断裂系统构造演化的走向差异。此外，大断层位移与上覆较厚的盐层密切相关，凸显了盐对位移聚集的促进作用。这些发现有助于更好地认识逆冲断层的发育模式及其影响因素。

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引用次数: 0

Trace element geochemistry of scheelite: Implications for W mineralization and fluid evolution of the Huangjindong Au-(W) deposit, South China 白钨矿微量元素地球化学：对黄金洞金(W)矿床成矿和流体演化的指示意义

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-07 DOI: 10.1016/j.jseaes.2025.106857

Parfait M. Mupenge , Degao Zhai , Xiangfa Song , Qingqing Zhao , Gang Zhao , Jiajun Liu , Jian-Feng Gao

Scheelite is common in quartz vein–type Au deposits and provides a valuable tracer of ore-forming fluid sources and mineralization conditions. The Huangjindong Au deposit, in the central Jiangnan orogen of South China, contains approximately 80 tons of gold, where scheelite is abundant within Au-bearing quartz veins. Through cathodoluminescence (CL) and LA-ICP-MS analyses, this study investigates the trace element geochemistry of scheelite from the Huangjindong Au-(W) deposit to evaluate its implications for W mineralization and ore-forming fluid evolution. Textural evidences reveal two scheelite types, i.e., anhedral-subhedral and coarse-grained, with both showing homogeneous cathodoluminescence features. The geochemical investigations showed that both types of scheelite are characterized by high Sr/Mo ratios, low REE with slight MREE enrichment, and positive Eu anomalies, consistent with orogenic gold systems. The Huangjindong scheelite exhibits low Mo, Nb, Ta, and Na but elevated Sr, reflecting relatively low-temperature, reducing hydrothermal conditions. The large Y/Ho ratios further suggest variations during fluid evolution. These geochemical signatures indicate a metamorphic fluid of deep-crustal origin, subsequently modified by fluid–rock interactions. Comparisons with global datasets show that the Huangjindong scheelite closely resembles those from orogenic gold systems but differs from skarn or porphyry deposits, supporting an orogenic classification for this deposit. This study demonstrates that scheelite trace elements provide a robust tool for constraining ore-forming fluid conditions and discriminating genetic types of gold deposits.

白钨矿普遍存在于石英脉型金矿床中，为成矿流体来源和成矿条件提供了有价值的示踪剂。金矿床位于华南江南造山带中部，含金量约80吨，含金石英脉中含白钨矿丰富。通过阴极发光（CL）和LA-ICP-MS分析，研究了黄金洞金(W)矿床白钨矿的微量元素地球化学特征，探讨了其对W成矿和成矿流体演化的指示意义。白钨矿有两种类型，即半面形白钨矿和粗粒白钨矿，均表现出均匀的阴极发光特征。地球化学研究表明，这两类白钨矿均具有Sr/Mo比值高、REE低且MREE轻度富集、Eu正异常等特征，与造山带金体系一致。黄金洞白钨矿Mo、Nb、Ta、Na低，Sr高，反映了相对低温、还原热液条件。较大的Y/Ho比值进一步表明了流体演化过程中的变化。这些地球化学特征表明这是一种深地壳起源的变质流体，随后被流体-岩石相互作用所改变。黄金洞白钨矿与造山带金系统的白钨矿相似，但与夕卡岩或斑岩矿床不同，支持该矿床的造山带分类。研究表明，白钨矿微量元素为限定成矿流体条件和判别金矿床成因类型提供了强有力的工具。

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引用次数: 0

Redox conditions during the formation of sedimentary manganese deposits in the Cryogenian Nanhua Basin, South China 华南华南盆地低温系沉积锰矿床形成过程中的氧化还原条件

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-07 DOI: 10.1016/j.jseaes.2025.106856

Jian Wang , Ping Wang , Liangjun Yuan , Wen Pan , Shuaiyao Wang

The Nanhua Basin of South China recorded Cryogenian stratigraphic sequence, including the syn-Sturtian and Marinoan sediments. The Datangpo Formation precipitated during the interglacial interval between the two global glaciations, and a Mn-carbonate layer was preserved at the basal Datangpo Formation. However, the redox conditions of the Cryogenian manganese deposits in the Nanhua Basin remain poorly studied. In this study, the Mn-carbonates are characterized by high total nitrogen (TN) contents, ranging from 0.03 % to 0.11 % (mean 0.07 %) in the ZK4207 drillcore and 0.03 % to 0.09 % (mean 0.05 %) in the PM002 section. Combined with total organic carbon (TOC) and K₂O data, TN shows no relationship with TOC, but a positive relationship with K₂O, indicating that N was preserved as NH₄⁺ bound to silicates in sediments. Meanwhile, the Mn-carbonates also recorded high nitrogen isotope compositions (δ¹⁵N) (ZK4207 drillcore: mean + 2.7 ‰; PM002 section: mean 3.0 ‰), indicating the intermittently oxic condition in the deep Nanhua Basin. During organic matter mineralization, ¹⁴N-enriched NH₄⁺ was partially oxidized, leading to the ¹⁵N-enrichment in the residual NH₄⁺, which was subsequently bound to silicates and preserved in the sediments. The redox variations in the deep basin result in the Mn²⁺ oxidation under oxic condition, then the formed Mn-oxides/oxyhydroxides were subsequently reduced to Mn-carbonates. This study provides new insights for the redox fluctuations in the Nanhua Basin and the metallogenetic process of the manganese deposits.

华南南华盆地记录了低温系层序，包括同斯图梯和马里诺梯沉积。大唐坡组沉积于两次全球冰期之间的间冰期，基底大唐坡组沉积了一层锰碳酸盐层。然而，对华南盆地低温系锰矿床氧化还原条件的研究仍然较少。在本研究中，mn -碳酸盐岩具有较高的总氮（TN）含量，在ZK4207岩心中为0.03% ~ 0.11%（平均0.07%），在PM002岩心中为0.03% ~ 0.09%（平均0.05%）。结合总有机碳（TOC）和K2O数据，TN与TOC不相关，而与K2O呈正相关，说明N以NH4+结合的形式保存在沉积物中。同时，mn -碳酸盐岩也记录了较高的氮同位素组成（δ15N）（ZK4207岩心平均值为+ 2.7‰，PM002岩心平均值为3.0‰），表明南华盆地深部处于间歇氧合状态。在有机质矿化过程中，富含14n的NH4+被部分氧化，导致15n在残余NH4+中富集，随后与硅酸盐结合并保存在沉积物中。深盆地的氧化还原变化导致Mn2+在氧化条件下氧化，形成的mn -氧化物/氢氧化物随后被还原为mn -碳酸盐岩。该研究为华南盆地氧化还原波动和锰矿床的成矿过程提供了新的认识。

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引用次数: 0

Unraveling origin of intraplate nephelinites: insights from seismic tomography and geochemistry 揭示板内辉石的起源：来自地震层析成像和地球化学的见解

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-06 DOI: 10.1016/j.jseaes.2025.106853

Ke-Chun Hong , Jin-Cheng Ma , Feng Wang , Yi-Ni Wang , Wen-Liang Xu

This paper presents the results of an integrated seismic tomographic and geochemical investigation of Cenozoic intraplate nephelinites from Shandong Province in the eastern North China Craton to constrain origin of intraplate nephelinites. Seismic tomography images show that delaminated crust has entered the mantle transition zone (MTZ) where it interacted with the stagnant Pacific slab. The nephelinites have similar geochemical compositions to experimental melts of carbonated eclogite, and EMI basalts as well as kimberlites in trace element patterns, implying an essential role of deep carbonate melts. These data, together with their low δ²⁶Mg and high δ⁶⁶Zn values, indicate that carbonated silicate melts derived by partial melting of carbonated eclogites may have contributed to the formation of these nephelinites. Our new findings suggest that interactions between delaminated crust and the stagnant Pacific slab in the MTZ generated the intraplate nephelinitic volcanism.

本文介绍了华北克拉通东部山东地区新生代板内辉砾岩的地震层析和地球化学综合调查结果，以限制板内辉砾岩的成因。地震层析成像显示，分层地壳已进入地幔过渡带（MTZ），并与停滞的太平洋板块相互作用。其地球化学成分与碳酸化榴辉岩实验熔体、EMI玄武岩以及微量元素模式的金伯利岩相似，暗示了深层碳酸盐岩熔体的重要作用。这些数据与它们的低δ26Mg和高δ66Zn值一起表明，碳酸化榴辉岩部分熔融产生的碳酸化硅酸盐熔体可能对这些辉辉岩的形成有贡献。我们的新发现表明，MTZ的脱层地壳与停滞的太平洋板块之间的相互作用产生了板内辉闪质火山作用。

引用次数: 0

Lithospheric structure of the northeastern margin of the Tibetan plateau revealed by ambient noise tomography

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-05 DOI: 10.1016/j.jseaes.2025.106864

Gong Deng , Jianshe Lei , Dapeng Zhao , Junmeng Zhao , Rui Gao , Zhuo Ye

The northeastern margin of the Tibetan plateau is key to understanding the uplift mechanism of active orogenic systems. In this work we determine detailed 3-D shear-wave velocity (Vs) tomography of the lithosphere beneath the Qilian block and the Ordos and Alxa blocks to study the growth mechanism of the northeastern margin of the Tibetan plateau. Rayleigh-wave phase velocity dispersions at periods of 5–50 s are extracted from seismograms recorded at 336 broadband stations in the study area during September 2013 to April 2015. Our tomography reveals clear boundaries between different tectonic blocks, with high-Vs features beneath the stable Alxa and Ordos blocks and pronounced low-Vs anomalies mainly beneath the Qilian block. The low-Vs anomalies extend vertically from the upper mantle to ∼20 km depth in the crust and horizontally northward beneath the Hexi corridor basin. Furthermore, these crustal low-Vs anomalies are mainly confined to the west of the Riyueshan fault at ∼104°E and not beyond the eastern boundary of the Longxi block. Our results indicate that localized crustal delamination and mantle upwelling beneath the Qilian block have weakened the lower crust and enabled weak materials to infiltrate northward beneath the Hexi corridor. This process likely drives rapid uplift and promotes broad orogenic activity along the plateau northern boundary. In contrast, the Longxi and Ordos blocks exhibit mechanically relatively strong lithosphere which primarily forms narrow orogenic belts at the boundary. We infer that these contrasting differences likely arise from variations in the subduction angle of the Indian slab from the west to east.

从研究区336个宽带台站2013年9月至2015年4月的地震记录中提取了5 ~ 50s周期的瑞利波相速度频散。层析成像显示不同构造块体之间边界清晰，在稳定的阿拉善和鄂尔多斯块体下方具有高v值特征，而在祁连块体下方具有明显的低v值异常。低vs异常从上地幔垂直延伸至地壳深处~ 20km，水平向北延伸至河西走廊盆地下方。此外，这些地壳低vs异常主要局限于日月山断裂以西~ 104°E，未超出陇西地块的东部边界。结果表明，祁连地块下的局部地壳拆沉和地幔上升流削弱了下地壳，使弱物质向河西走廊下方北渗。这一过程可能推动了高原北部边界的快速隆升，并促进了广泛的造山活动。陇西地块和鄂尔多斯地块则表现出较强的机械岩石圈，主要在边界处形成狭窄的造山带。我们推断，这些对比差异可能是由印度板块自西向东俯冲角度的变化引起的。

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引用次数: 0

δ13C and δ18O differences between biogenic and non-biogenic carbonates in Chinese loess-paleosol sections: Implications for paleoclimate proxies 中国黄土-古土壤剖面生物成因与非生物成因碳酸盐δ13C和δ18O差异：古气候代用意义

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-04 DOI: 10.1016/j.jseaes.2025.106855

Chenglong Li , Xuefen Sheng , Rui Bao , Jiawei Da

Geochemical proxies of carbonates are widely applied in Quaternary paleoclimate reconstructions. However, differences in formation processes among secondary carbonate types can yield divergent environmental signals, making their reconstructions not directly comparable. Here, we compare the δ¹³C and δ¹⁸O values of two types of secondary carbonates from the Mangshan loess-paleosol section on the southeastern margin of the Chinese Loess Plateau: non-biogenic carbonates (bulk, clay-sized samples and nodules) and biogenic carbonates (fossil land snail shells), to evaluate their consistency and identify the causes of discrepancies. Fossil snail shells exhibit only minor aragonite-to-calcite transformation (average calcite content 5.4%), whereas non-biogenic carbonates consist of secondary calcite without detrital dolomite. The δ¹³C values of land snail shells vary from −6.87 ‰ to −1.59 ‰, lower than those of bulk samples (from −3.57 ‰ to −1.51 ‰), clay-sized samples (from −5.12 ‰ to −1.27 ‰), and nodules (from −3.46 ‰ to −1.56 ‰). These isotopic offsets are also observed in modern samples and other sections, mainly reflecting differences in plant types recorded by the two carbonate types, along with a minor contribution from atmospheric CO₂. By contrast, the δ¹⁸O values of shells (−9.61 ‰ to −2.83 ‰) are higher than those of bulk samples (−9.88 ‰ to −8.77 ‰), clay-sized samples (−10.34 ‰ to −7.61 ‰), and nodules (−9.92 ‰ to −9.10 ‰). This suggests that stronger evaporative enrichment occurred in surface soil water for snail shell formation, compared with subsurface soil water involved in pedogenic carbonate formation. Overall, the geochemical differences between biogenic and non-biogenic carbonates arise from distinct formation processes; therefore, using those geochemical proxies for paleoclimate reconstruction needs caution.

碳酸盐岩地球化学指标在第四纪古气候重建中有着广泛的应用。然而，次生碳酸盐岩类型之间形成过程的差异会产生不同的环境信号，使得它们的重建不能直接比较。本文比较了黄土高原东南缘Mangshan黄土-古土壤剖面中2种次生碳酸盐的δ13C和δ18O值，即非生物成因碳酸盐（块状、粘土大小的样品和结核）和生物成因碳酸盐（陆地螺壳化石），评价了它们的一致性，并确定了差异的原因。螺壳化石仅表现出少量文石向方解石的转化（平均方解石含量5.4%），而非生物成因碳酸盐由次生方解石组成，不含碎屑白云岩。陆螺壳的δ13C值在- 6.87‰~ - 1.59‰之间变化，低于大块样品（- 3.57‰~ - 1.51‰）、黏土样品（- 5.12‰~ - 1.27‰）和结核样品（- 3.46‰~ - 1.56‰）。在现代样品和其他剖面中也观察到这些同位素偏移，主要反映了两种碳酸盐类型记录的植物类型的差异，以及大气CO2的少量贡献。相比之下，贝壳样品的δ18O值（- 9.61‰~ - 2.83‰）高于大块样品（- 9.88‰~ - 8.77‰）、黏土样品（- 10.34‰~ - 7.61‰）和结核样品（- 9.92‰~ - 9.10‰）。这表明，在螺壳形成过程中表层土壤水分的蒸发富集作用强于在成土碳酸盐岩形成过程中的地下土壤水分。总体而言，生物成因与非生物成因碳酸盐的地球化学差异源于不同的形成过程；因此，使用这些地球化学指标进行古气候重建需要谨慎。

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引用次数: 0

Can Nb-enriched arc basalts result from mixing of boninite and ocean island basalt magmas? A case study from Jurassic gabbroic rocks of western Iran (Sanandaj-Sirjan Zone) 富铌弧玄武岩是否由博宁岩和洋岛玄武岩岩浆混合形成？伊朗西部（sanandaji - sirjan地区）侏罗系辉长岩研究

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-11-03 DOI: 10.1016/j.jseaes.2025.106852

Amir Esna-Ashari , Jamshid Hassanzadeh , Antonio Langone , Fatemeh Sarjoughian , Massimo Tiepolo

The origin of Nb-rich basalts—specifically high-Nb basalts (HNB) and Nb-enriched basalts (NEB)—is a key issue in subduction-related igneous petrology. The gabbroic rocks from the Alvand Plutonic Complex (ALPC) in the Neo-Tethyan Sanandaj-Sirjan Zone of Iran, with zircon U–Pb crystallization ages of 165 ± 2 Ma, provide a valuable natural setting for investigating these magmas. The trace element chemistry of gabbroic clinopyroxene and amphibole indicates crystallization from a parental melt with similarities with both HNB and OIB-type alkaline magmas. Major and trace element data show that the clinopyroxene compositions lie between those of OIB-like melts and highly depleted ultramafic boninitic rocks (HDUR) found in the same plutonic belt. Similarly, bulk-rock gabbros that are the intrusive equivalent of basalts span a compositional range from HNB to NEB and are transitional between OIB and HDUR end-members.

We propose that the ALPC gabbros formed by mixing between an OIB-type magma, sourced from upwelling asthenosphere through a slab window, and a highly depleted boninitic melt sourced from partial melting of a depleted mantle wedge. This mixing model contrasts with the widely accepted adakitic model, which involves melting of a mantle wedge previously metasomatized by slab-derived melts. Our findings highlight the overlooked role of boninitic magmas in generating Nb-rich basalts and suggest that variable proportions of OIB and boninitic components can produce the compositional spectrum observed in HNB and NEB worldwide.

富铌玄武岩（特别是高铌玄武岩（HNB）和富铌玄武岩（NEB））的成因是与俯冲有关的火成岩岩石学的一个关键问题。伊朗新特提斯Sanandaj-Sirjan地区Alvand深部杂岩（ALPC）的锆石U-Pb结晶年龄为165±2 Ma，为研究这些岩浆提供了有价值的自然背景。辉长岩斜辉石和角闪石的微量元素化学特征表明，它们是由母熔融体结晶而成，与HNB型和oib型碱性岩浆相似。主量元素和微量元素数据表明，斜辉石的组成介于oib类熔体和在同一深成矿带中发现的高度贫化超镁铁性硼质岩（HDUR）之间。同样，块状辉长岩是侵入岩，相当于玄武岩，其组成范围从HNB到NEB，是OIB和HDUR端元之间的过渡。我们认为，ALPC辉长岩是由一种源自软流圈通过板窗上涌的oib型岩浆与一种源自枯竭地幔楔的部分熔融的高度枯竭的硼岩质熔体混合形成的。这种混合模式与广泛接受的埃达克岩模式形成对比，后者涉及到先前由板块衍生熔体交代的地幔楔的熔融。我们的研究结果强调了在富铌玄武岩的形成过程中被忽视的美美质岩浆的作用，并表明不同比例的OIB和美美质成分可以产生在世界范围内HNB和NEB中观察到的成分谱。

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引用次数: 0

High-pressure abiotic methane production in the refractory peri-Siberian forearc mantle recorded by olivine-hosted fluid inclusions (Eastern Sayan, southern Siberia) 南西伯利亚东萨彦地区含橄榄石流体包裹体记录的难熔性西伯利亚弧前地幔高压非生物甲烷生产

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-10-31 DOI: 10.1016/j.jseaes.2025.106850

Vasiliy A. Belyaev , Marina A. Gornova , Sergei Yu. Skuzovatov , Anas A. Karimov , Igor S. Sharygin , Alexander Ya. Medvedev , Yuri D. Shcherbakov

The redox state of fluids migrating above subduction zones is crucial for understanding of complex processes of element cycling and magma generation. In this contribution, we report the secondary fluid inclusions (FIs) in olivine from refractory peridotites of the Khara-Nur ophiolite, previously interpreted as a fragment of fossil subcontinental lithospheric mantle experienced melt interaction and retrograde metamorphism above a subduction zone. Fluid inclusions accompany serpentine (mainly antigorite) veinlets and altogether reflect limited and focused hydration within ∼ 400–600 °C at forearc depths. Raman spectroscopy of FIs revealed dominant CH₄ and rare H₂ gases, graphite, serpentinization minerals (antigorite/chrysotile, brucite, magnetite), and rarely, carbonates. Part of FIs contains CH₄ ± graphite only. The qualitative estimation of elemental budget in fluid inclusions by LA-ICP-MS indicates weak Na ± Cl ± Cu enrichment, while the other elements (including REE, HSFE, FME) are generally below quantification limits. CH₄ in serpentine-bearing FIs is resulted from post-entrapment internal serpentinization of host olivine by an oxidized (H₂O–CO₂ bearing) slab-derived fluid. In contrast, CH₄ in serpentine-free FIs represents reduced fluid, evolved from H₂O–CO₂ slab-derived fluid during progressive serpentinization of reduced (down to ΔFMQ −3) peridotitic environment and CO₂ transformation into CH₄ via reactions with serpentinization-derived H₂. If so, the mantle–wedge refractory (meta)peridotites may act as a filter that transforms oxidized subduction fluids into the reduced species and decreases fluid elemental cargo. As a result, local and/or focused hydration of the wedge peridotites may be pivotal for controlling the redox state of carbon in the peridotitic mantle. Alternatively, contrasting CH₄– and H₂O–CO₂–bearing fluids in FIs may record multiple episodes of fluid interaction via devolatilization of reduced or oxidized crustal lithologies of the oceanic slab.

俯冲带上迁移流体的氧化还原状态对于理解元素旋回和岩浆生成的复杂过程至关重要。在这篇文章中，我们报道了哈拉-努尔蛇绿岩中橄榄石中的次生流体包裹体（FIs），这些包裹体以前被解释为在俯冲带之上经历熔体相互作用和逆行变质作用的次大陆岩石圈地幔化石碎片。流体包裹体伴随着蛇纹石（主要是反长花岗岩）细脉，并在弧前深度的~ 400-600°C范围内反映出有限和集中的水化作用。FIs的拉曼光谱显示主要的CH4和稀有的H2气体，石墨，蛇纹石化矿物（辉长岩/温石棉，水镁石，磁铁矿），以及罕见的碳酸盐。部分FIs仅含CH4±石墨。LA-ICP-MS对包裹体元素收支进行定性估算，结果表明包裹体中Na±Cl±Cu富集较弱，其余元素（包括REE、HSFE、FME）均低于定量限。含蛇纹岩岩石中的CH4是包裹体包裹后被氧化（含H2O-CO2）的板状衍生流体对寄主橄榄石进行内部蛇纹岩化作用的结果。相比之下，不含蛇纹岩的FIs中的CH4代表还原流体，是在还原（降至ΔFMQ−3）橄榄岩环境的逐步蛇纹岩化过程中由H2O-CO2板源流体演化而来的，并通过与蛇纹岩化衍生的H2反应将CO2转化为CH4。如果是这样，地幔楔的难熔（元）橄榄岩可能起到过滤作用，将氧化俯冲流体转化为还原物质，减少流体元素货量。因此，楔形橄榄岩的局部和/或集中水化作用可能是控制橄榄岩地幔中碳氧化还原状态的关键。另外，FIs中含CH4 -和h2o - co2流体的对比可能记录了通过海洋板块还原或氧化的地壳岩性的脱挥发而发生的多期流体相互作用。

{"title":"High-pressure abiotic methane production in the refractory peri-Siberian forearc mantle recorded by olivine-hosted fluid inclusions (Eastern Sayan, southern Siberia)","authors":"Vasiliy A. Belyaev , Marina A. Gornova , Sergei Yu. Skuzovatov , Anas A. Karimov , Igor S. Sharygin , Alexander Ya. Medvedev , Yuri D. Shcherbakov","doi":"10.1016/j.jseaes.2025.106850","DOIUrl":"10.1016/j.jseaes.2025.106850","url":null,"abstract":"<div><div>The redox state of fluids migrating above subduction zones is crucial for understanding of complex processes of element cycling and magma generation. In this contribution, we report the secondary fluid inclusions (FIs) in olivine from refractory peridotites of the Khara-Nur ophiolite, previously interpreted as a fragment of fossil subcontinental lithospheric mantle experienced melt interaction and retrograde metamorphism above a subduction zone. Fluid inclusions accompany serpentine (mainly antigorite) veinlets and altogether reflect limited and focused hydration within ∼ 400–600 °C at forearc depths. Raman spectroscopy of FIs revealed dominant CH<sub>4</sub> and rare H<sub>2</sub> gases, graphite, serpentinization minerals (antigorite/chrysotile, brucite, magnetite), and rarely, carbonates. Part of FIs contains CH<sub>4</sub> ± graphite only. The qualitative estimation of elemental budget in fluid inclusions by LA-ICP-MS indicates weak Na ± Cl ± Cu enrichment, while the other elements (including REE, HSFE, FME) are generally below quantification limits. CH<sub>4</sub> in serpentine-bearing FIs is resulted from post-entrapment internal serpentinization of host olivine by an oxidized (H<sub>2</sub>O–CO<sub>2</sub> bearing) slab-derived fluid. In contrast, CH<sub>4</sub> in serpentine-free FIs represents reduced fluid, evolved from H<sub>2</sub>O–CO<sub>2</sub> slab-derived fluid during progressive serpentinization of reduced (down to ΔFMQ −3) peridotitic environment and CO<sub>2</sub> transformation into CH<sub>4</sub> via reactions with serpentinization-derived H<sub>2</sub>. If so, the mantle–wedge refractory (meta)peridotites may act as a filter that transforms oxidized subduction fluids into the reduced species and decreases fluid elemental cargo. As a result, local and/or focused hydration of the wedge peridotites may be pivotal for controlling the redox state of carbon in the peridotitic mantle. Alternatively, contrasting CH<sub>4</sub>– and H<sub>2</sub>O–CO<sub>2</sub>–bearing fluids in FIs may record multiple episodes of fluid interaction via devolatilization of reduced or oxidized crustal lithologies of the oceanic slab.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"295 ","pages":"Article 106850"},"PeriodicalIF":2.4,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145466995","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

Tectono-magmatic evolution of the Ambela granitic complex, Northwest Himalayas, Pakistan: Insights from LA-ICP-MS U–Pb zircon geochronology, Lu–Hf isotope, and trace element geochemistry 巴基斯坦西北喜马拉雅Ambela花岗岩杂岩的构造-岩浆演化：LA-ICP-MS U-Pb锆石年代学、Lu-Hf同位素和微量元素地球化学的启示

IF 2.4 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-10-29 DOI: 10.1016/j.jseaes.2025.106846

Mehboob ur Rashid , Hafiz U. Rehman , Hao-Yang Lee , Sun-Lin Chung , Kaushik Das , Muhammad Jawad Zeb , Nasir Ahmad , Muhammad Hussain , Hiroshi Yamamoto

Ambela Granitic Complex (AGC) is a dominant alkaline magmatic body exposed in the Peshawar Plain Alkaline Igneous Province of the NW Himalaya. However, its petrogenetic source was not clear till data. This study aims to investigate petrogenetic source and magma origin of AGC using whole-rock geochemistry, zircon U–Pb/Lu–Hf isotope and trace element geochemistry. Oscillatory-zoned zircons in AGC yielded ²⁰⁶Pb/²³⁸U age spanning between 282 and 287 Ma, indicating granite emplacement during Permian. Positive εHf(t) values of + 1.4 to + 13.8 from zircons confirm mantle-derived juvenile material slightly mixed with continental crust. Whole-rock data show the studied rocks are ferroan, high-K calc-alkaline, and A-type granites. Chondrite-normalized REE patterns of zircon, characterized by LREE depletion, positive Ce and negative Eu anomalies, with elevated U/Yb, Sc/Yb and Nb/Yb ratios, indicate crystallization from an evolved, oxidized melt that underwent plagioclase fractionation in an anorogenic within-plate rift related setting. Zircon-saturation (722 to 858 °C) and Ti-in-zircon (692 to 820 °C) thermometry indicate high-temperature magmatism typical of granitic system. The petrogenetic sequence suggests that initial partial melting of lower crustal rocks was triggered by upwelling of the asthenosphere causing doming and crustal thinning, followed by magmatic differentiation that generated AGC rocks. The presence of mafic dykes in AGC, along with Panjal Trap basalts, represents bimodal magmatism, indicative of mantle plume input. The geochemical affinity and temporal overlap of AGC with the coeval widespread Permian magmatic episode in the Himalayan region suggest an intracontinental rifting related to the Cimmerian orogeny in the northern margin of Gondwana.

安贝拉花岗岩体（Ambela Granitic Complex， AGC）是西北喜马拉雅白沙瓦平原碱性火成岩省的一个优势碱性岩浆体。但其成因尚无确切资料。利用全岩地球化学、锆石U-Pb / Lu-Hf同位素、微量元素地球化学等方法研究AGC的成岩来源和岩浆成因。AGC振荡带锆石的206Pb/238U年龄为282 ~ 287 Ma，表明花岗岩侵位在二叠纪。锆石εHf(t)正值为+ 1.4 ~ + 13.8，证实地幔源幼代物质与大陆地壳有轻微混合。全岩资料显示，所研究的岩石为铁质花岗岩、高钾钙碱性花岗岩和a型花岗岩。锆石球粒陨石归一化的稀土元素模式，以LREE亏缺、正Ce和负Eu异常、U/Yb、Sc/Yb和Nb/Yb比值升高为特征，表明锆石的结晶来自于一个演化的氧化熔体，该熔体在与板块内裂谷有关的造山带中经历了斜长石分选。锆石饱和度（722 ~ 858℃）和锆石中钛（692 ~ 820℃）的测温表明该岩浆活动为典型的花岗岩体系高温岩浆活动。岩石成因序列表明，软流圈上升流引发下地壳岩石初始部分熔融，形成穹隆和地壳减薄，岩浆分异形成AGC岩。AGC中的基性岩脉与Panjal圈闭玄武岩的存在，代表了双峰岩浆作用，表明地幔柱的输入。AGC与喜马拉雅地区同时期广泛分布的二叠纪岩浆事件的地球化学亲和性和时间重叠表明，冈瓦纳北缘的西美纪造山运动与AGC的陆内裂谷作用有关。

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引用次数: 0