Journal of Asian Earth Sciences最新文献

Geochemical evidence for Late Eocene to Oligocene climate change in the Lühe Basin of the southeastern Tibetan Plateau

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-10 DOI: 10.1016/j.jseaes.2025.106612

Hao Cui , He Tang , Zhifeng Liu , Jianghao Bai , Juncai Chen , Gangjian Wei

The transition from the Eocene to the Oligocene marks a critical phase in Earth’s history, characterized by a shift from greenhouse to icehouse conditions. While global climate changes during this period have been extensively studied, continental geological evidence particularly from landmasses such as the Tibetan Plateau (TP) and its surrounding regions remained limited. Addressing this research gap, our study employs high-resolution trace element geochemical records from the Lühe Basin at the southeastern margin of the Tibetan Plateau (SEMTP) to systematically investiate sediment provenance and weathering processes from the Late Eocene to the Oligocene (35.5–25.5 Ma). The results indicate that the sediment provenance in the Lühe Basin shows limited variation across different scales of provenance analysis, and lithological have little effect on the reconstruction of chemical weathering records. Based on various geochemical proxies, three distinct phases in the evolution of weathering are identified: (1) a phase of progressively intensified weathering during the Late Eocene, (2) a marked decline in weathering intensity during the Eocene-Oligocene Transition (EOT), and (3) a phase of recovery followed by sustained fluctuations in the Oligocene. Furthermore, we discuss the potential global climatic and regional environmental drivers underlying each phase.

从始新世到渐新世的过渡标志着地球历史的一个关键阶段，其特点是从温室条件到冰室条件的转变。虽然这一时期的全球气候变化已被广泛研究，但大陆地质证据，尤其是来自青藏高原（TP）等陆地及其周边地区的证据仍然有限。针对这一研究空白，我们的研究利用青藏高原东南缘吕河盆地（SEMTP）的高分辨率痕量元素地球化学记录，系统研究了晚始新世至渐新世（35.5-25.5Ma）的沉积物来源和风化过程。结果表明，吕梁盆地沉积物产状在不同尺度的产状分析中变化有限，岩性对化学风化记录的重建影响不大。根据各种地球化学代用指标，确定了风化演化的三个不同阶段：(1)晚始新世风化逐渐加剧的阶段；(2)始新世-渐新世过渡（EOT）时期风化强度明显下降的阶段；(3)渐新世持续波动之后的恢复阶段。此外，我们还讨论了每个阶段背后潜在的全球气候和区域环境驱动因素。

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引用次数: 0

Tectonic variations in NS-trending rifts, southern Tibetan Plateau: insights from hydrothermal emissions and seismic activities

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-10 DOI: 10.1016/j.jseaes.2025.106599

Jiao Tian , Xiaocheng Zhou , Minghui Liao , Miao He , Zhaojun Zeng , Yucong Yan , Bingyu Yao , Yuwen Wang , Shihan Cui , Gaoyuan Xing , Chunhui Cao , Liwu Li , Changhui Ju

A series of NS-trending rifts in the Tibetan Plateau interior provide a window for unraveling its rifting properties and geodynamic mechanisms. In this study, we focused on hydrothermal degassing and seismic activities to identify the differential tectonic status of each rift. Analysis of hydrothermal gaseous components reveals that crustal metamorphic products accumulate in the western rifts and the easternmost rift while growing mantle-derived volatiles contribute in the northeast rifting zones. The flow rate of uprising mantle-derived fluids ranges from 0.01 mm/yr to 2972 mm/yr and the total ³He fluxes vary in 1.0 × 10⁻⁷ – 1.2 × 10⁻⁵ mol/km²/yr. The distribution of H₂-enriched hot springs coincides with the young initiation time of the rifts, indicating the young active tectonic setting in the eastern rifts. Spatially discernible characteristics are also observed in seismic activity. Earthquakes occurring in western rifts have relatively shallow focal depths and low frequencies and magnitudes, suggesting that faulting structures are active within the middle-shallow crust. In contrast, more frequent strong and deep-focus earthquakes occurred in the northeastern rifting areas, outlining the large-scale fault planes that dipped into the lower crust or even the bottom of the lithosphere and served as an enhanced conduit for the growing contribution of mantle-derived volatiles at the surface. Our interpretation emphasizes that the underlying Indian slab is unlikely to experience wide tearing beneath Tibet and that eastward-enhanced seismic activity and degassing are likely driven by eastward-propagating lateral slab detachment. These findings have profound implications for the post-collisional evolution of the Tibetan Plateau.

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引用次数: 0

Organic matter accumulation and carbon sequestration in the Paleocene-Eocene Thermal Maximum: Insights from the Kongdian Formation in Cangdong Sag, Bohai Bay Basin

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-10 DOI: 10.1016/j.jseaes.2025.106606

Wenwen Li , Xianfeng Tan , Wei Jiang , Xiaowei Dong , Dunfan Wang , Long Luo , Jia Wang , Jianping Liu , Xueqi Yan , Chenlin Huang

The Paleocene-Eocene Thermal Maximum (PETM) has attracted much attention due to resembling the modern climatic change. This study focuses on the organic matter accumulation and carbon sequestration under the PETM by the Kongdian Formation in the Cangdong Sag, Bohai Bay Basin using petrography, geochemistry, and X-ray diffraction (XRD). The PETM happened in the second member of the Kongdian Formation (Ek₂) which experienced a process of warm-dry to hot-humid to warm-dry variations. Hence the Ek₂^1-2 section has been divided into pre-, core-, and post-PETM. During the pre-PETM, a continuous hot climate strengthened the evaporation to induce the lake salinizing which aggravated water stratification and reducing condition. Intense hydrological cycle resulted in rising terrestrial flux and falling salinity, and more oxidic water column at the core-PETM stage. The salinity continuously falls from the highest point at the post-PETM stage, corresponding to the evaporation weakening and terrestrial input increasing. This caused gradually weakening water stratification and oxidic water column. More saline and reducing conditions promoted the boom of aquatic organism and favorable preservation, so more saturated and aromatic hydrocarbons have been formed at the pre- and post-PETM stages. By contrast, the core-PETM section contains more higher plants with unfavorable preservation, generating less asphaltene. Combined with carbonate and TOC contents, the interplay of organic–inorganic carbon sequestration occurred at the pre- and post-PETM stages, distinct from that at the core-PETM. Injection of light oil from the pre- and post-PETM sections leads to high OSI values of the core-PETM which has good shale oil potentials.

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引用次数: 0

New insights into the middle Eocene environmental conditions and biogeographic setting of the Fergana Basin (Central Asia): Micropaleontological approaches

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-10 DOI: 10.1016/j.jseaes.2025.106613

Yaroslav S. Trubin , Alina Winkler , Ilja Kogan , Andreas Brosig , Jingwen Zhang , Moriaki Yasuhara , Skye Yunshu Tian , Vladimir A. Marinov , Martin R. Langer

The middle Eocene transformation of the Fergana Basin, one of the largest basins in Central Asia situated between the Peri-Tethys and the Asian continent, plays a key role in understanding the transition to regional aridification of Central Asia. The basin’s transformation not only contributed to regional aridification but also affected global ocean circulation and climate. This study examines the micropaleontological communities, especially foraminifera and ostracoda assemblages as proxies, within the Turkestan and Rishtan formations, which corresponding to the Lutetian and Bartonian stages of the middle Eocene, respectively. Statistical analyses were performed to estimate species diversity, structure, and composition of the microfauna, shedding new light on their distribution across facies and stratigraphic profiles, and contributing to a paleoecological reconstruction. The environment is interpreted as a nearshore coastal intertidal or high subtidal zone with a substrate consisting of low-oxygen subsurface sediments and well-oxygenated benthic zone surface habitats. The results of this research provide a deeper understanding of the area, proposing that the middle Eocene of Fergana Basin was a complex configurated realm rather than a gulf, as previously recognized.

{"title":"New insights into the middle Eocene environmental conditions and biogeographic setting of the Fergana Basin (Central Asia): Micropaleontological approaches","authors":"Yaroslav S. Trubin , Alina Winkler , Ilja Kogan , Andreas Brosig , Jingwen Zhang , Moriaki Yasuhara , Skye Yunshu Tian , Vladimir A. Marinov , Martin R. Langer","doi":"10.1016/j.jseaes.2025.106613","DOIUrl":"10.1016/j.jseaes.2025.106613","url":null,"abstract":"<div><div>The middle Eocene transformation of the Fergana Basin, one of the largest basins in Central Asia situated between the Peri-Tethys and the Asian continent, plays a key role in understanding the transition to regional aridification of Central Asia. The basin’s transformation not only contributed to regional aridification but also affected global ocean circulation and climate. This study examines the micropaleontological communities, especially foraminifera and ostracoda assemblages as proxies, within the Turkestan and Rishtan formations, which corresponding to the Lutetian and Bartonian stages of the middle Eocene, respectively. Statistical analyses were performed to estimate species diversity, structure, and composition of the microfauna, shedding new light on their distribution across facies and stratigraphic profiles, and contributing to a paleoecological reconstruction. The environment is interpreted as a nearshore coastal intertidal or high subtidal zone with a substrate consisting of low-oxygen subsurface sediments and well-oxygenated benthic zone surface habitats. The results of this research provide a deeper understanding of the area, proposing that the middle Eocene of Fergana Basin was a complex configurated realm rather than a gulf, as previously recognized.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"288 ","pages":"Article 106613"},"PeriodicalIF":2.7,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143822388","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

The significance of the high-amplitude magnetic anomaly belt in the seismotectonics of mid-west Taiwan

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-05 DOI: 10.1016/j.jseaes.2025.106598

Wen-Bin Doo , Yin-Sheng Huang , Wen-Nan Wu , Ching-Yu Cheng , Chung-Liang Lo , Hsueh-Fen Wang , Shiou-Ya Wang , Yin-Tung Yen

In mid-west Taiwan, there is a unique zone with high crustal magnetization called Lukang Magnetization High (LMH), which is believed to significantly influence earthquake activity in middle Taiwan. According to the magnetic anomaly feature in the Taiwan region, the LMH is the inversion result of the eastern part of the high-amplitude magnetic anomaly zone (NSCSMA) found in the northern South China Sea continental margin. To better understand the connection between this magnetic high (HMAZ) and background tectonic features, this study analyzes the magnetic data in mid-west Taiwan. We used wavelet spectrum analysis and compact inversion techniques to determine its causal source. Wavelet spectrum analysis results show that the wavelength of the major magnetic signal of the HMAZ is 180 km, indicating the source depth of approximately 25 km. The compact inversion results reveal high-susceptibility materials distributed around 20–30 km depth. P-wave velocity models suggest that the causal source of the HMAZ could be located in the lower crust and/or upper mantle and belong to the Eurasia plate. Based on the previous analysis results of the NSCSMA and our observation, we propose that the serpentinized materials may be the causal source of the HMAZ. Moreover, based on the regional seismicity characteristics, our findings indicate that the deformation front plays a more crucial role in the seismotectonic of mid-west Taiwan than the HMAZ.

{"title":"The significance of the high-amplitude magnetic anomaly belt in the seismotectonics of mid-west Taiwan","authors":"Wen-Bin Doo , Yin-Sheng Huang , Wen-Nan Wu , Ching-Yu Cheng , Chung-Liang Lo , Hsueh-Fen Wang , Shiou-Ya Wang , Yin-Tung Yen","doi":"10.1016/j.jseaes.2025.106598","DOIUrl":"10.1016/j.jseaes.2025.106598","url":null,"abstract":"<div><div>In mid-west Taiwan, there is a unique zone with high crustal magnetization called Lukang Magnetization High (LMH), which is believed to significantly influence earthquake activity in middle Taiwan. According to the magnetic anomaly feature in the Taiwan region, the LMH is the inversion result of the eastern part of the high-amplitude magnetic anomaly zone (NSCSMA) found in the northern South China Sea continental margin. To better understand the connection between this magnetic high (HMAZ) and background tectonic features, this study analyzes the magnetic data in mid-west Taiwan. We used wavelet spectrum analysis and compact inversion techniques to determine its causal source. Wavelet spectrum analysis results show that the wavelength of the major magnetic signal of the HMAZ is 180 km, indicating the source depth of approximately 25 km. The compact inversion results reveal high-susceptibility materials distributed around 20–30 km depth. P-wave velocity models suggest that the causal source of the HMAZ could be located in the lower crust and/or upper mantle and belong to the Eurasia plate. Based on the previous analysis results of the NSCSMA and our observation, we propose that the serpentinized materials may be the causal source of the HMAZ. Moreover, based on the regional seismicity characteristics, our findings indicate that the deformation front plays a more crucial role in the seismotectonic of mid-west Taiwan than the HMAZ.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"288 ","pages":"Article 106598"},"PeriodicalIF":2.7,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816213","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

Biodiversity and paleoenvironments of vertebrate-rich Eocene marine deposits (Lutetian) of the tropical western Neotethys: New insights from the Arabian Platform

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-05 DOI: 10.1016/j.jseaes.2025.106604

M. Deville de Periere , Guillaume Guinot , Sylvain Adnet , Sylvia Riechelmann , Alison Murray , Didier Merle , Christian Cesari , Chris Reid , Mohammed Sadah

The Eocene deposits of Saudi Arabia (Dammam Formation) are characterized by intertidal to shallow marine carbonate rocks interbedded with meter-scale shale members (Midra and Saila shales). The latter are dated from the middle Eocene and include large numbers of marine vertebrates, dominated by elasmobranch (sharks, skates, and rays) teeth. The rich fossil assemblage comprises at least 13 elasmobranch taxa (including 8 different sharks and 3 batomorph taxa) and at least 7 bony fish taxa. This assemblage is described for the first time from the Arabian Platform (western margin of the Neotethys) and is critically important to understand the changes in circum Tethyan marine biotas during the Eocene. The larger elasmobranchs are dominated by lamniform sharks, such as “Carcharias” koerti, Brachycarcharias cf. lerichei and Striatolamia cf. macrota, along with the tiger shark Galeocerdo eaglesomei, the hammerhead shark Sphyrna sp., and myliobatoids. Teleost fishes appear less diversified in the area and are dominated by Eotrigonodon and Pycnodus species. A low-diversity benthic fauna including bivalves, gastropods, echinoids and corals was found along with the neritic elasmobranch and teleost taxa. The fish assemblage found in the present study is consistent with other middle Eocene faunas worldwide, especially in the tropical Neotethys seaway. Biostratigraphic analyses and strontium isotope ratio measurements from tooth enameloid confirm a Lutetian age (possibly refined to mid-Lutetian). The variety of taxa recovered in Saudi Arabia enables a preliminary reconstruction of the likely interactions between the various fossil groups and their broad paleoenvironments. Apex predators characterized by large lamniform and carcharhiniform sharks probably hunted in shallow near shore waters, where other fish (including eagle rays, carpet sharks, sawfish, and bony fish) were dwelling.

{"title":"Biodiversity and paleoenvironments of vertebrate-rich Eocene marine deposits (Lutetian) of the tropical western Neotethys: New insights from the Arabian Platform","authors":"M. Deville de Periere , Guillaume Guinot , Sylvain Adnet , Sylvia Riechelmann , Alison Murray , Didier Merle , Christian Cesari , Chris Reid , Mohammed Sadah","doi":"10.1016/j.jseaes.2025.106604","DOIUrl":"10.1016/j.jseaes.2025.106604","url":null,"abstract":"<div><div>The Eocene deposits of Saudi Arabia (Dammam Formation) are characterized by intertidal to shallow marine carbonate rocks interbedded with meter-scale shale members (Midra and Saila shales). The latter are dated from the middle Eocene and include large numbers of marine vertebrates, dominated by elasmobranch (sharks, skates, and rays) teeth. The rich fossil assemblage comprises at least 13 elasmobranch taxa (including 8 different sharks and 3 batomorph taxa) and at least 7 bony fish taxa. This assemblage is described for the first time from the Arabian Platform (western margin of the Neotethys) and is critically important to understand the changes in circum Tethyan marine biotas during the Eocene. The larger elasmobranchs are dominated by lamniform sharks, such as “<em>Carcharias” koerti</em>, <em>Brachycarcharias</em> cf. <em>lerichei</em> and <em>Striatolamia</em> cf. <em>macrota</em>, along with the tiger shark <em>Galeocerdo eaglesomei</em>, the hammerhead shark <em>Sphyrna</em> sp., and myliobatoids. Teleost fishes appear less diversified in the area and are dominated by <em>Eotrigonodon</em> and <em>Pycnodus</em> species. A low-diversity benthic fauna including bivalves, gastropods, echinoids and corals was found along with the neritic elasmobranch and teleost taxa. The fish assemblage found in the present study is consistent with other middle Eocene faunas worldwide, especially in the tropical Neotethys seaway. Biostratigraphic analyses and strontium isotope ratio measurements from tooth enameloid confirm a Lutetian age (possibly refined to mid-Lutetian). The variety of taxa recovered in Saudi Arabia enables a preliminary reconstruction of the likely interactions between the various fossil groups and their broad paleoenvironments. Apex predators characterized by large lamniform and carcharhiniform sharks probably hunted in shallow near shore waters, where other fish (including eagle rays, carpet sharks, sawfish, and bony fish) were dwelling.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"288 ","pages":"Article 106604"},"PeriodicalIF":2.7,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816288","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

Contributions of thermoelastic strain to apparent annual variations in four-component borehole strain: A case study from Gaotai station in the NE margin of the Tibetan Plateau

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-05 DOI: 10.1016/j.jseaes.2025.106600

Xiaolin Yang , Jinling Yang , Hang Li , Jun Wang

Clarifying the physical mechanisms underlying near-surface annual deformation remains a major challenge in crustal dynamics research. For the four-component borehole strain observation networks in mainland China, a few stations are apparently dominated by annual fluctuations. However, only a limited number of specific studies have been carried out to dynamically assess the physical characteristics of these signals. Considering the fact that atmospheric temperature is a major factor inducing annual variations in crustal deformation, the Gaotai station was thus selected as a typical example diagnosis and a half-space model with a decoupling layer was used to quantitatively assess the thermo-effects of annual atmospheric temperature variation on the four-component borehole strain. The results show that an annual temperature variation with amplitude of 16.60 ℃ can induce a theoretical thermal strain of the 10^-6 magnitude at a borehole depth of 44.97 m; additionally, both amplitude and phase of the modeled values closely align with the measured strain time series, suggesting that the annual variation signal of the four-component borehole strain recorded at Gaotai station mainly originates from the annual atmospheric temperature changes. This geodynamical investigation can help to quantitatively elucidate the annual variation mechanism of the multi-component borehole strain and advance our understanding of thermo-deformation processes in shallow crust.

{"title":"Contributions of thermoelastic strain to apparent annual variations in four-component borehole strain: A case study from Gaotai station in the NE margin of the Tibetan Plateau","authors":"Xiaolin Yang , Jinling Yang , Hang Li , Jun Wang","doi":"10.1016/j.jseaes.2025.106600","DOIUrl":"10.1016/j.jseaes.2025.106600","url":null,"abstract":"<div><div>Clarifying the physical mechanisms underlying near-surface annual deformation remains a major challenge in crustal dynamics research. For the four-component borehole strain observation networks in mainland China, a few stations are apparently dominated by annual fluctuations. However, only a limited number of specific studies have been carried out to dynamically assess the physical characteristics of these signals. Considering the fact that atmospheric temperature is a major factor inducing annual variations in crustal deformation, the Gaotai station was thus selected as a typical example diagnosis and a half-space model with a decoupling layer was used to quantitatively assess the thermo-effects of annual atmospheric temperature variation on the four-component borehole strain. The results show that an annual temperature variation with amplitude of 16.60 ℃ can induce a theoretical thermal strain of the 10<sup>-6</sup> magnitude at a borehole depth of 44.97 m; additionally, both amplitude and phase of the modeled values closely align with the measured strain time series, suggesting that the annual variation signal of the four-component borehole strain recorded at Gaotai station mainly originates from the annual atmospheric temperature changes. This geodynamical investigation can help to quantitatively elucidate the annual variation mechanism of the multi-component borehole strain and advance our understanding of thermo-deformation processes in shallow crust.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"288 ","pages":"Article 106600"},"PeriodicalIF":2.7,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143785812","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

Insights into tectonic lineaments patterns and crustal architectures beneath the Carlsberg Ridge: Implications for mineral exploration

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-05 DOI: 10.1016/j.jseaes.2025.106602

Satya Narayan

This study focuses on the Carlsberg Ridge’s complex geological structures, characterized by rugged topography, seismicity, and significant hydrothermal activity, which have led to the deposition of economically valuable sulfide minerals. Using an integrated geophysical approach, including gravity data analysis, lineament mapping, Euler depth estimation, seismicity analysis, and spectral depth examination, we investigate the structural and crustal architecture beneath the Carlsberg Ridge. The analysis utilizes high-resolution GECO global gravity models, to generate detailed subsurface images. A comparative study of GECO-derived and shipborne Free-air gravity data shows strong agreement, with higher correlation and lower RMS error. The study also employs the regional-residual gravity separation, edge enhancement filters, and Euler deconvolution method, which aid in identifying mineralization zones and active/inactive vent sites conducive to mineral accumulation. Results indicate topographic and gravity anomalies linked to shallow-to-moderate depth discontinuities, active tectonics, hydrothermal venting, and mineralization processes. Identified zones shows high lineament density, moderate crustal thickness, and shallower Moho depths. The THVH technique delineated faults and fractures with dominant orientations of NE-SW, NW-SE, ENE-WSW, N-S, and E-W directions, respectively. Seismic events along the ridge axis, with focal depths of 9.0–10.5 km and magnitudes of 4.0–5.9 Mb, correlate with these zones. Mineralized areas align with high seismicity, shallow crustal features, and hydrothermal vent activity. These findings emphasize the Carlsberg Ridge’s potential for deep-sea mineral exploration, offering valuable insights into seafloor mineralization processes. This study provides a foundation for future geophysical and geochemical surveys in mid-oceanic ridge environments.

{"title":"Insights into tectonic lineaments patterns and crustal architectures beneath the Carlsberg Ridge: Implications for mineral exploration","authors":"Satya Narayan","doi":"10.1016/j.jseaes.2025.106602","DOIUrl":"10.1016/j.jseaes.2025.106602","url":null,"abstract":"<div><div>This study focuses on the Carlsberg Ridge’s complex geological structures, characterized by rugged topography, seismicity, and significant hydrothermal activity, which have led to the deposition of economically valuable sulfide minerals. Using an integrated geophysical approach, including gravity data analysis, lineament mapping, Euler depth estimation, seismicity analysis, and spectral depth examination, we investigate the structural and crustal architecture beneath the Carlsberg Ridge. The analysis utilizes high-resolution GECO global gravity models, to generate detailed subsurface images. A comparative study of GECO-derived and shipborne Free-air gravity data shows strong agreement, with higher correlation and lower RMS error. The study also employs the regional-residual gravity separation, edge enhancement filters, and Euler deconvolution method, which aid in identifying mineralization zones and active/inactive vent sites conducive to mineral accumulation. Results indicate topographic and gravity anomalies linked to shallow-to-moderate depth discontinuities, active tectonics, hydrothermal venting, and mineralization processes. Identified zones shows high lineament density, moderate crustal thickness, and shallower Moho depths. The THVH technique delineated faults and fractures with dominant orientations of NE-SW, NW-SE, ENE-WSW, N-S, and E-W directions, respectively. Seismic events along the ridge axis, with focal depths of 9.0–10.5 km and magnitudes of 4.0–5.9 Mb, correlate with these zones. Mineralized areas align with high seismicity, shallow crustal features, and hydrothermal vent activity. These findings emphasize the Carlsberg Ridge’s potential for deep-sea mineral exploration, offering valuable insights into seafloor mineralization processes. This study provides a foundation for future geophysical and geochemical surveys in mid-oceanic ridge environments.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"288 ","pages":"Article 106602"},"PeriodicalIF":2.7,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143799257","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

Rift-related explosive volcanism on the eve of the Cambrian ‘explosion’ on the Olenek Uplift (northeastern margin of Siberian Craton)

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-05 DOI: 10.1016/j.jseaes.2025.106592

Ivan F. Chayka , Olga P. Izokh , Vladimir I. Rogov , Evgeny V. Vinogradov , Elena A. Vasyukova , Boris M. Lobastov , Sergey N. Rudnev , Andrey E. Izokh , Dmitriy V. Grazhdankin

Igneous occurrences comprising stratiform volcanic breccia, diatremes, basalt flows and feeders, and dolerite sills exhibit structural relationships with the Ediacaran–Cambrian boundary strata on the Olenek Uplift (northeastern Siberian Craton). A U-Pb date of 543.9 ± 0.24 Ma for zircons from the volcaniclastics (Bowring et al., 1993) had been considered as the age of the magmatic complex and used to constraint the Ediacaran-Cambrian boundary. We conducted a multifaceted study of this complex shedding additional light on its classification, petrology, tectonics and emplacement regime. We distinguish between basic and high-potassic rock varieties and attribute this diversity to a syn-emplacement overprint by K⁺-bearing sedimentary brines. All the rocks are co-magmatic, originated from a mantle-derived alkali-basaltic melt, and constitute a single event herein formally described as the Tas-Yuryakh complex. Its parental melt supposedly originated via 15–20 % melting of a garnet lherzolite at 65–70 km depth due to reaction of a plume with moderately enriched lithospheric mantle at the passive continental margin. These data combined with the geological evidence corroborate an earlier conclusion that the Tas-Yuryakh complex together with the adjacent Kharaulakh occurrence mark a rift structure that existed at ∼ 540 Ma in an ocean basin between Siberia and Baltica. The volcanic events took place over > 600 km² in shallow-depth coastal settings over a drowned carstified carbonate platform. The reaction of the hot magma with seawater and underground brines could have released a substantial mass of halogen- and boron-bearing compounds into the water and atmosphere affecting local environment and biota.

{"title":"Rift-related explosive volcanism on the eve of the Cambrian ‘explosion’ on the Olenek Uplift (northeastern margin of Siberian Craton)","authors":"Ivan F. Chayka , Olga P. Izokh , Vladimir I. Rogov , Evgeny V. Vinogradov , Elena A. Vasyukova , Boris M. Lobastov , Sergey N. Rudnev , Andrey E. Izokh , Dmitriy V. Grazhdankin","doi":"10.1016/j.jseaes.2025.106592","DOIUrl":"10.1016/j.jseaes.2025.106592","url":null,"abstract":"<div><div>Igneous occurrences comprising stratiform volcanic breccia, diatremes, basalt flows and feeders, and dolerite sills exhibit structural relationships with the Ediacaran–Cambrian boundary strata on the Olenek Uplift (northeastern Siberian Craton). A U-Pb date of 543.9 ± 0.24 Ma for zircons from the volcaniclastics (<span><span>Bowring et al., 1993</span></span>) had been considered as the age of the magmatic complex and used to constraint the Ediacaran-Cambrian boundary. We conducted a multifaceted study of this complex shedding additional light on its classification, petrology, tectonics and emplacement regime. We distinguish between basic and high-potassic rock varieties and attribute this diversity to a <em>syn</em>-emplacement overprint by K<sup>+</sup>-bearing sedimentary brines. All the rocks are co-magmatic, originated from a mantle-derived alkali-basaltic melt, and constitute a single event herein formally described as the Tas-Yuryakh complex. Its parental melt supposedly originated via 15–20 % melting of a garnet lherzolite at 65–70 km depth due to reaction of a plume with moderately enriched lithospheric mantle at the passive continental margin. These data combined with the geological evidence corroborate an earlier conclusion that the Tas-Yuryakh complex together with the adjacent Kharaulakh occurrence mark a rift structure that existed at ∼ 540 Ma in an ocean basin between Siberia and Baltica. The volcanic events took place over > 600 km<sup>2</sup> in shallow-depth coastal settings over a drowned carstified carbonate platform. The reaction of the hot magma with seawater and underground brines could have released a substantial mass of halogen- and boron-bearing compounds into the water and atmosphere affecting local environment and biota.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"288 ","pages":"Article 106592"},"PeriodicalIF":2.7,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816212","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

Origin of chromitites and dunites of the Dazhuqu ophiolite in the Yarlung-Zangbo ophiolite zone, Tibet

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences

Pub Date : 2025-04-05 DOI: 10.1016/j.jseaes.2025.106609

Yu-Wei She , Fa-Hui Xiong , Qiu-Hong Xie

The origin of chromitites in ophiolites remains a topic of debate. The Dazhuqu ophiolitic massif located in the central segment of the Yarlung-Zangbo ophiolite zone contains podiform chromitites. The massive chromitites exhibit significantly low Cr# (38–47) in chromite. In contrast, the disseminated chromitites have relatively wide range of Cr# (16–64) in chromite. The dunites can be classified into two group: low-Cr# chromite-bearing dunites (Cr# = 19–51) and high-Cr# chromite-bearing dunites (Cr# = 74–83). The chromite of harzburgites show similar Cr# range (27–55) to that of the disseminated chromitites and low-Cr# chromite-bearing dunites. The negative correlation between Ti and Cr# along with the positive correlation between Ni and Mg# in chromite suggests that the massive chromitites formed through the physical sorting and accumulation of chromite grains in the melt conduits. The compositional patterns of chromite in the disseminated chromitites and low-Cr# chromite-bearing dunites resemble those of the harzburgites, implying that their chromite may have inherited compositional signatures from the surrounding harzburgites. In contrast, the chromite in the high-Cr# chromite-bearing dunites exhibits compositional patterns associated with boninitic melts. The coexistence of the chromitites and dunites with lower Cr# of chromite and high-Cr# chromite-bearing dunites indicate that the Dazhuqu massif was once modified by both MORB-like and boninitic melts, causing highly variable Cr# of chromite. A model of subduction initiation accounts for the magmatic evolutionary history of the chromitites and mantle sequence of the Dazhuqu massif.

{"title":"Origin of chromitites and dunites of the Dazhuqu ophiolite in the Yarlung-Zangbo ophiolite zone, Tibet","authors":"Yu-Wei She , Fa-Hui Xiong , Qiu-Hong Xie","doi":"10.1016/j.jseaes.2025.106609","DOIUrl":"10.1016/j.jseaes.2025.106609","url":null,"abstract":"<div><div>The origin of chromitites in ophiolites remains a topic of debate. The Dazhuqu ophiolitic massif located in the central segment of the Yarlung-Zangbo ophiolite zone contains podiform chromitites. The massive chromitites exhibit significantly low Cr# (38–47) in chromite. In contrast, the disseminated chromitites have relatively wide range of Cr# (16–64) in chromite. The dunites can be classified into two group: low-Cr# chromite-bearing dunites (Cr# = 19–51) and high-Cr# chromite-bearing dunites (Cr# = 74–83). The chromite of harzburgites show similar Cr# range (27–55) to that of the disseminated chromitites and low-Cr# chromite-bearing dunites. The negative correlation between Ti and Cr# along with the positive correlation between Ni and Mg# in chromite suggests that the massive chromitites formed through the physical sorting and accumulation of chromite grains in the melt conduits. The compositional patterns of chromite in the disseminated chromitites and low-Cr# chromite-bearing dunites resemble those of the harzburgites, implying that their chromite may have inherited compositional signatures from the surrounding harzburgites. In contrast, the chromite in the high-Cr# chromite-bearing dunites exhibits compositional patterns associated with boninitic melts. The coexistence of the chromitites and dunites with lower Cr# of chromite and high-Cr# chromite-bearing dunites indicate that the Dazhuqu massif was once modified by both MORB-like and boninitic melts, causing highly variable Cr# of chromite. A model of subduction initiation accounts for the magmatic evolutionary history of the chromitites and mantle sequence of the Dazhuqu massif.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"289 ","pages":"Article 106609"},"PeriodicalIF":2.7,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817817","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