Article
Geosciences, Multidisciplinary
Yusuke Shimura, Tetsuya Tokiwa, Hiroshi Mori, Makoto Takeuchi, Yui Kouketsu
Summary: The study conducted structural analyses and peak-temperature estimations on Cretaceous subduction complexes in southwest Japan. Different deformation characteristics and peak temperatures were observed in three complexes arranged in descending order of structural position, suggesting diachronous occurrences in different tectonic settings within the subduction zone.
JOURNAL OF ASIAN EARTH SCIENCES
(2021)
Article
Geochemistry & Geophysics
Masaki Enami, Yuki Wakasugi, Motohiro Tsuboi
Summary: In the Sanbagawa metamorphic belt, the semi-pelitic band has compositions intermediate between the basic and pelitic bands, with peak metamorphic conditions estimated at 1.0-1.2 GPa/600-630 degrees C.
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY
(2021)
Article
Geochemistry & Geophysics
Zhiqiang Lu, Ichiko Shimizu, Tetsumaru Itaya
Summary: In this study, K-Ar dating was conducted on weakly metamorphosed sedimentary rocks collected from the Kanto Mountains in Central Japan to determine the metamorphic ages of the accretionary complexes in the Northern Chichibu Belt in SW Japan. The results revealed variations in the ages of chert and red shale compared to mudstone and tuff in the same strata, possibly due to the influence of submarine hydrothermal activities. The mineral ages of illite samples with different grain sizes indicated older ages and higher crystallinity for larger grain-size classes. The peak metamorphic ages of different units within the accretionary complexes were determined, suggesting a major structural discontinuity in the Middle Jurassic accretionary complexes.
Article
Geochemistry & Geophysics
Jeremy L. Asimus, Nathan R. Daczko, Isra S. Ezad
Summary: Core complexes are dome-like structures that form in tectonic settings like mid-ocean ridges and continental rifted margins, providing insights into deep Earth processes. The Entia Dome in central Australia is a remarkable core complex that formed during a contractional mountain-building event. Through fieldwork, petrography, geochemistry, and experiments, we present evidence of melt-present deformation in the lower crust beneath the Entia Dome. This melt-weakening, in conjunction with the structural architecture of the dome, suggests a decoupling between upper crustal thrusting and lower crustal extrusion during the mountain-building event.
Article
Geosciences, Multidisciplinary
Haroldo Vizan
Summary: The Central Patagonian Igneous Metamorphic Belt on the southwestern margin of the North Patagonian Massif, Argentina, is a geologically significant belt that has been subject to debates regarding its origin and geological events. Paleogeographic reconstructions reveal two main tectonic processes, the Chanic and Gondwanan events, which contributed to the formation and collapse of an accretionary orogen in this region.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2023)
Article
Geosciences, Multidisciplinary
Stephen Collett, Karel Schulmann, Pierig Deiller, Pavla Stipska, Vit Peresty, Marc Ulrich, Yingde Jiang, Luc de Hoym de Marien, Jitka Mikova
Summary: This article investigates the high-pressure and high-temperature metamorphism during the Mid-Devonian period in the Variscan Orogeny, focusing on the geological characteristics of the Marianske Lazne Complex (MLC). The unique position of MLC at the base of its original upper plate is highlighted. The study reveals that both MLC and the upper plate developed above a relatively unaltered Neoproterozoic lithospheric mantle, which is important for reconstructing the original architecture of the Variscan terranes.
GEOSCIENCE FRONTIERS
(2022)
Article
Geochemistry & Geophysics
Jack James Percival, Jiri Konopasek, Robert Anczkiewicz, Morgan Ganerod, Jiri Slama, Roberto Sacks de Campos, Maria de Fatima Bitencourt
Summary: The Dom Feliciano Belt in southern Brazil and Uruguay represents the western half of a Neoproterozoic orogenic belt in the South Atlantic region. The nature of orogenesis in this belt has been debated due to limited geochronological data. In this study, metamorphosed rocks from the Brusque Complex in the northern Dom Feliciano Belt were analyzed, showing evidence of orogenic metamorphism and early crustal thickening. The results suggest that orogenesis in this belt was initiated by rift-basin inversion driven by far-field forces transmitted through the crust.
Article
Geology
Claude Nambaje, Ian S. Williams, K. Sajeev
Summary: The SIMS U-Th-Pb dating technique has provided direct measurements of the ages of cassiterite in pegmatite and quartz vein Sn mineralisation in the Karagwe-Ankole Belt, Rwanda. The study identified three generations of Sn mineralisation associated with magmatic and metamorphic processes during different periods of Rodinian and Gondwanan assembly, helping to place the mineralisation in a tectonic context. The recognition of different Sn mineralisation episodes and their links to local geological settings, igneous activity and regional tectonism will aid in exploration for ore-grade Sn deposits in Rwanda and neighboring countries.
ORE GEOLOGY REVIEWS
(2021)
Article
Geochemistry & Geophysics
Salviano da Silva, Andres Bustamante, Camilo Bustamante, Agustin Cardona, Caetano Juliani
Summary: The origin of the Raspas Metamorphic Complex and its metamorphic conditions have been unclear. This study provides new data on the geochemistry, metamorphism, and cooling age, shedding light on the protolith, metamorphic conditions, and tectonic implications for the Northern Andes.
Article
Geosciences, Multidisciplinary
Fang Wang, Fulai Liu, Ngo Xuan Thanh, Lei Ji, Jianjiang Zhu, Huining Wang
Summary: Metasedimentary rocks in the Son La area of northwestern Vietnam provide important evidence for the geological evolution of the region. Detrital zircons from these rocks were dated and yielded ages between 2787 and 618 Ma. The age patterns and Hf isotope compositions suggest a connection with the western Yangtze Block. Metamorphic zircon and monazite from these rocks constrain Triassic tectonic events at 247-240 Ma, indicating a subduction-collision orogenic belt.
Article
Geology
Yan Yang, Chenyue Liang, Franz Neubauer, M. Santosh, Jan D. Kramers, Changqing Zheng, Huiming Zhang
Summary: This study re-evaluates the Central Zone of the Limpopo Belt in southern Africa, revealing early Precambrian tectonic processes. Based on petrology, U-Pb zircon ages, and major and trace element data of high-pressure mafic granulites in the Sand River area, the research identifies protoliths formed at a mid-ocean ridge around 2.8 Ga. Three metamorphic stages are recognized in the studied samples, indicating a clockwise P-T path and important information about Neoproterozoic collisional orogeny, independent orogeny, and subsequent exhumation and cooling. U-Pb zircon dating shows protolith formation prior to 2.72 Ga and metamorphic ages of 2.72 Ga (peak) and 2.0 Ga (post-peak cooling) for the mafic granulites. The metamorphic evolution reconstructed in this study suggests a Neoarchean collision between the Kaapvaal and Zimbabwe cratons, followed by a discrete Paleoproterozoic orogenic overprint and post-orogenic exhumation and cooling.
INTERNATIONAL GEOLOGY REVIEW
(2023)
Article
Geochemistry & Geophysics
Claudio Alejandro Salazar-Mora, Victor Sacek
Summary: By using numerical models, researchers explored the effects of quiescence between orogeny and rifting on the pre-rift lithosphere and subsequent conjugate rifted margin configuration. The study found that long periods of tectonic quiescence can lead to hyperextended conjugate rifted margins, while narrower orogenic wedges are less affected. This research supports the development of conjugate rifted margins in the Atlantic Ocean.
Review
Geosciences, Multidisciplinary
Qiangqiang Zhang, Xiaoying Gao, Renxu Chen, Yongfei Zheng
Summary: This study presents an integrated study of metamorphic records along the China Central Orogenic System (CCOS) to shed light on the tectonic evolution of the Eastern Tethys tectonic domain. The results show that continental subduction and collision mainly occurred in the early and later convergent stages, while intracontinental rifting mainly occurred in the post-convergent stage.
SCIENCE CHINA-EARTH SCIENCES
(2023)
Article
Geochemistry & Geophysics
Laura Culi, Jesus Sole, Marc Campeny, Jeffry A. G. Oalmann
Summary: This study investigates garnets from the southwestern Oaxacan Complex in Mexico for the first time, providing insights into their petrographical, geochemical, and geothermobarometrical characteristics. The results show that the garnets in different lithotypes have similar almandine proportions but differ in pyrope concentrations and element enrichments. The pressure obtained in this study is higher than in the northern part of the Complex, indicating different structural levels within the orogen.
Article
Geosciences, Multidisciplinary
Ze-Ming Zhang, Hui-Xia Ding, Xin Dong, Zuo-Lin Tian, Richard M. Palin, M. Santosh, Yan-Fei Chen, Yuan-Yuan Jiang, Sheng-Kai Qin, Dong-Yan Kang, Wen-Tan Li
Summary: This paper investigates the formation and evolution processes of the Gangdese arc in southern Tibet through the study of Mesozoic magmatic rocks. The arc experienced different tectonic, magmatic, and metamorphic evolution stages, including normal subduction, shallow subduction, mid-oceanic ridge subduction, and flat subduction.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2022)
Article
Geosciences, Multidisciplinary
Hikaru Sawada, Yusuke Sawaki, Shuhei Sakata, Akira Ishikawa, Brian Muteta, Yukio Isozaki, Shigenori Maruyama
Summary: This study used in-situ U-Pb dating and Re-Os isotopic analysis to reveal the evolution of the Shurugwi greenstone belt, indicating that Wanderer and Mont d'Or formations were deposited around 3.0-3.01 billion years ago, while the SGB was formed around 3.0-3.01 billion years ago and was tectonically emplaced over the 3.01 billion years old orthogneiss.
JOURNAL OF AFRICAN EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Tetsuji Onoue, Katsuhito Soda, Yukio Isozaki
Summary: The study investigates the geochemical characteristics of late Permian seafloor rocks, revealing the evolution of oceanic anoxia that occurred before the end-Permian mass extinction event. The appearance of euxinic conditions with hydrogen sulfide may be linked to intensified continental weathering and temperature rise.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Paleontology
Sena Kono, Yukio Isozaki, Tomohiko Sato, Moriaki Yasuhara, Wei Liu, Xing-Liang Zhang
Summary: Stratigraphic analysis of small shelly fossils (SSFs) in the lower Cambrian Zhongyicun Member in the Chengjiang area of Yunnan, China reveals unique SSFs and suggests the presence of arthropod body fossils in the Fortunian, earlier than previously believed.
Article
Geosciences, Multidisciplinary
Masafumi Saitoh, Yukio Isozaki
Summary: The study investigates the impact of methane release associated with the Siberian Traps volcanism during the end-Permian extinction on the global methane cycle, and analyzes the carbon isotopic composition variations at Chaotian, South China. The research suggests that changes in marine carbon isotopic composition may be influenced by factors such as primary productivity collapse and volcanic activity.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
Victor P. Nechaev, Evgene Sklyarov, Yukio Isozaki, Nikolay N. Kruk, Alexey Travin, Yukiyasu Tsutsumi, Eugenia Nechaeva
Summary: The study in the Sergeevka belt in coastal South Primorye, Far East Russia, revealed the presence of more than 30 mafic dykes, which are divided into two distinct age/geochemistry suites showing different origins and affected by a transition in mantle source type.
Editorial Material
Geosciences, Multidisciplinary
Robert A. Gastaldo, Yukio Isozaki, Evelyn Kustatscher, Robert Reisz, ShuZhong Shen
FRONTIERS IN EARTH SCIENCE
(2021)
Editorial Material
Paleontology
Yukio Isozaki
PALEONTOLOGICAL RESEARCH
(2023)
Article
Paleontology
Yukio Isozaki
Summary: This article reviews the current status of research on Paleozoic mass extinctions, highlighting the categorization of extinction causes and the exploration of non-bolide extraterrestrial causes. Recent studies suggest that extraterrestrial processes, such as supernova explosions and migration of dark clouds, may have played a role in the extinctions. These findings provide new insights and explanations for our understanding of the Paleozoic mass extinctions.
PALEONTOLOGICAL RESEARCH
(2023)
Article
Geology
Juliana Ferreira Godot Souza, Yukio Isozaki, Yukiyasu Tsutsumi, Renata da Silva Schmitt, Silvia Regina de Medeiros, Cicera Neysi de Almeida, Bruno Cesar Araujo, Pamela Richetti, Evania Alves da Silva, Aristoteles de Morais Rios Netto
Summary: This study presents U-Pb dating of detrital zircons from sandstones of the Araripe basin in NE Brazil, providing insights into the Mesozoic paleogeography. The findings suggest significant changes in provenance during the Later Jurassic to mid-Cretaceous, reflecting the rapid evolution of paleogeographic scenarios in northwest Gondwana. An alternative model for the paleogeography of northwest Gondwana is proposed, explaining the occurrence of Tethyan fauna in the Araripe Basin.
SEDIMENTARY GEOLOGY
(2022)
Article
Geography, Physical
Satoshi Yoshida, Yukio Isozaki, Tomohito Nakano, Yukiyasu Tsutsumi
Summary: This study measured the Uranium-Pb ages of detrital zircons from sandstone samples collected in Nagasaki and Nishisonogi Peninsula, SW Japan. The results showed that the depositional ages of the sandstones ranged from Late Cretaceous to Eocene. The main provenances of the sandstones were identified to be the Ryoke/San-yo and San-in granite belts in SW Japan.
JOURNAL OF GEOGRAPHY-CHIGAKU ZASSHI
(2022)
Article
Geosciences, Multidisciplinary
Yukio Isozaki, Yusuke Sawaki, Hideki Iwano, Takafumi Hirata, Keitaro Kunugiza
Summary: This study analyzes the geochemistry and U-Pb age of zircons in the large granitoid boulders in the Jinzu Group in order to identify the origin of the Hida belt in central Japan. The results suggest that these boulders have typical A-type granite geochemistry and a Late Triassic age of approximately 220 Ma. The boulders are more likely to originate from the Hida belt rather than the eastern Songliao block in China, indicating the past occurrence of A-type granite in the Hida belt.
Article
Geosciences, Multidisciplinary
Masafumi Saitoh, Manabu Nishizawa, Kazumi Ozaki, Masayuki Ikeda, Yuichiro Ueno, Ken Takai, Yukio Isozaki
Summary: The Capitanian stage is a peculiar stage characterized by marine anoxia and a large extinction. Previous studies have confirmed the occurrence of marine anoxia at least locally in the Capitanian, but the spatial extent and duration of anoxia in the superocean Panthalassa during this stage have been poorly understood. This study provides new insights into the global nitrogen cycle and redox conditions, showing that the nitrogen source was substantially enriched in δ15N via denitrification within subsurface oxygen-deficient zones. Numerical modeling further reveals that reducing water masses prevailed at intermediate water depths in the superocean, contributing to the shelf extinction.
PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Masafumi Saitoh, Yuichiro Ueno, Yukio Isozaki, Naohiro Yoshida
Summary: Previous research on multiple sulfur isotopes in sedimentary pyrite at the end-Permian suggests a mixing of sulfur from two different sources, with noticeable sulfate reduction in deep waters. This challenges the traditional shoaling model and infers substantial variations in hydrogen sulfide concentration and upwelling rate during the Permian-Triassic transition.
Article
Geography, Physical
Yuto Ishizaka, Yukio Isozaki, Yukiyasu Tsutsumi
Summary: By measuring the U-Pb ages of detrital zircons in Cretaceous and Paleogene fore-arc sandstones of the Yezo Group in western Hokkaido, it was found that there was a significant transition in tectono-sedimentary history from Early Cretaceous dominance to mid- to Late Cretaceous dominance. This transition suggests a significant renewal of the surface crust in the provenance during the Albian. The coeval turnover in zircon age spectra of fore-arc sandstones along the Cretaceous East Asian margin implies a ubiquitous development of fore-arc basins and their provenances over more than 1,500 km before the Miocene opening of the Japan Sea.
JOURNAL OF GEOGRAPHY-CHIGAKU ZASSHI
(2021)
Article
Geography, Physical
Sena Kono, Yukio Isozaki, Tomohiko Sato, Xingliang Zhang, Wei Liu
Summary: The detailed lithostratigraphy of the Lower Cambrian in South China was analyzed at the Xiaolantian section in the Chengjiang area, Yunnan, revealing six distinct lithostratigraphic units and one particular terrigenous elastic unit in the middle. These beds were found to have been deposited in shallow marine settings in the Kangdian rift-related basin in western South China. The study also highlighted a significant unit composed of terrigenous elastics in the middle of the Zhongyicun Member, serving as a key bed for lithostratigraphical correlation within the basin.
JOURNAL OF GEOGRAPHY-CHIGAKU ZASSHI
(2021)
Review
Geosciences, Multidisciplinary
Fuquan Yang, Xinxia Geng, Zhixin Zhang, Guoren Liu, Hanqing Zhang
Summary: Northern Xinjiang in China is an important part of the Central Asian Orogenic Belt, characterized by multiple episodes and types of mineralization. Cu and Au deposits are mostly found in Altay, Junggar, and Tianshan, with minor occurrences in Beishan. The most common types of Cu-Au deposits are volcanogenic and porphyry deposits. The formation of Cu-Au deposits can be divided into five mineralization episodes, with the Devonian and Carboniferous being the main periods. These deposits developed in various tectonic settings, including island arc, continental arc, collision, and postcollisional extensional tectonics.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Jiang Zhu, Dan-yang Liu, Chao Chen, Song Chen, Yuan-bing Zou, Leonid Danyushevsky, Jing-meng Huang, Xiang-wei Tang
Summary: Numerous lode gold and silver deposits have been discovered in orogenic belts in China. This study focuses on the formation and fluid evolutions of the super-large Yingdongpo gold and giant Poshan silver deposits in the Tongbai-Dabie orogen. The results suggest that both deposits were formed concurrently with Early Cretaceous granitic magmatism and the ore-forming fluids were primarily of magmatic origin with meteoric water inputting. The gold mineralization is related to a change in the physicochemical properties of the fluids, while the silver mineralization is favored by progressive deposition of sulfides in a slowly cooling hydrothermal system.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Arun Bhadran, B. P. Duarah, Drishya Girishbai, Mohammad Atif Raza, Avi Mero, Sandeep Lahon, A. L. Achu, Girish Gopinath
Summary: The Brahmaputra foreland basin, known for its dynamic tectonism and sediment load, exhibits a variety of seismically generated soft sediment deformation structures (SSDS) such as clastic dikes, sand sills, and micro-faults. These structures, influenced by multiple strong seismic events, are characterized by their dimensions, intrusion angles, cross-cutting relations, wall shattering, and age. The study suggests that a significant earthquake with high intensity and magnitude might have caused liquefaction features in the area. The findings highlight the importance of studying SSDS in tectonically active regions with limited surface ruptures and dense alluvial cover.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Huan Wang, Lirong Dou, Xingyang Zhang, Jiquan Yin, Beiwei Luo, Haigang Duan, Peiguang Yang, Yifan Song
Summary: Quantitative analysis of sediment composition and microfacies helped identify changes in facies belts in the Cretaceous Mishrif Formation. The study demonstrated the importance of carbonate microfacies quantification and its implications for paleogeographic research.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Boran Wang, Zhilong Huang, Dongsheng Xiao, Haiyue Yu, Wenren Zeng, Xin Wang, Tong Qu, Zhiyuan Li, Yizhuo Yang
Summary: By systematically analyzing the source rocks of the Sangonghe Formation in the Taibei Sag, NW China, and using kerogen kinetics modeling, this study reveals the influence of geological conditions on hydrocarbon generation and expulsion. The source rocks in different environments show distinct geochemical characteristics and hydrocarbon generation potential.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Haiying Yang, Zhifang Zhao, Haifeng Fan, Min Zeng, Jiafei Xiao, Xiqiang Liu, Shengwei Wu, Jiangqin Chao, Yong Xia
Summary: This paper investigates the REE enrichment and the role of Fe/Mn (oxyhydr)oxides in marine phosphorites from the early Cambrian period in South China. The study reveals that Fe/Mn (oxyhydr)oxides play a crucial role in REE enrichment and are controlled by Fe-redox pumping.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Qing Li, Hongbin Wang, Feng Cai, Di Luo, Fanxing Kong, Ang Li, Xiting Liu
Summary: The elemental and isotopic compositions and abundance of carbonates in marine sediments are used to reconstruct ancient climate and ocean conditions. This study analyzed sediment samples from the Okinawa Trough to examine the relationship between carbonates' compositions and methane seepage and sea-level changes. The results indicate that both biogenic and authigenic carbonates are important factors in understanding paleoclimate and paleoceanography.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Maryam Akbarzadeh Aghdam, Abdolreza Ghods, Farhad Sobouti, Khalil Motaghi, Keith Priestley, Mohammad Enayat
Summary: The Makran subduction zone is difficult to monitor due to limited seismic activity, but a temporary seismic network was installed to investigate the relationship between different regions and detect seismicity. The observed seismicity suggests the presence of structural boundaries and seismically inactive areas.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Zhen-Yu Wang, Hong-Rui Fan, Hai-Dong She, Kui-Feng Yang
Summary: This study conducted detailed geochemical, geochronological and isotopic analyses on the Songxian syenite in the Qinling Orogen. The results revealed the magma sources, petrogenesis and geodynamic implications of this alkaline intrusion. The study suggests that the syenite was formed through multiple stages of magmatism, involving the partial melting of the enriched lithospheric mantle and mixing with melts derived from the lower crust.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Yu Li, Wen-Liang Xu, Xiao-Ming Zhang, Jie Tang
Summary: This study presents new zircon U-Pb-Hf and whole-rock geochemical data for Jurassic intrusive rocks in the Yanbian area of NE China, providing insights into the subduction history of the Paleo-Pacific Plate. The study reveals three stages of Jurassic magmatism in the area, indicating the presence of an active continental margin related to the initial subduction of the Paleo-Pacific Plate beneath the Eurasian continent.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Lina Ai, Shengfa Liu, Shuai Cong, Hui Zhang, Peng Cao, Kaikai Wu, Wenxing Ye, Che Abd Rahim Mohamed, Xuefa Shi
Summary: This study investigates the depositional configurations and sedimentary environments of the Malacca Strait through analyzing grain size characteristics and hydrographic data. The results show that residual sediments are concentrated in the central region, while modern terrigenous sediments are distributed along the coast of Malaysia and the northern region. The sedimentary environments are influenced by seasonal variations and hydrodynamic conditions.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Liang Xiao, Jia-qi Liang, Li-yan Guo, De-shuang Ji, Man Yuan, Xiang-chuan Li, Nan Sun, Zuo-chen Li
Summary: This study investigates the correlation between stable carbon isotopes of plant fossils and CO2 levels in the Jurassic period. The results suggest a weak correlation between the two, indicating caution is needed when using stable carbon isotopes to reconstruct high paleo-CO2 concentrations.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Xuli Yang, Feng Huang, Jifeng Xu, Xijun Liu, Liying Zhang, Zhao Zhang, Benyan Xu, Man Zhang, Yunchuan Zeng, Qian Liu, Mingda Lv
Summary: The extensively developed Early Cretaceous intermediate-felsic rocks in the northern North China Craton provide valuable insights into the nature of Paleo-Pacific subduction and associated geodynamic processes. Geochemical and geochronological analyses of trachyandesites and rhyolites from the eastern Hebei, northern NCC suggest that the trachyandesites likely originated from enriched mafic lower crust and the rhyolites are derived from the trachyandesitic magmas through fractional crystallization. The migration direction change of these rocks is believed to be primarily attributed to slab rollback of the subducting Paleo-Pacific Plate.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Wei Liu, Ping Gao, Xianming Xiao, Yanming Zhao, Yijie Xing, Jinku Li
Summary: The organic-rich shales of the Shuijingtuo Formation in China are an important target for shale gas exploration. The upper section of the formation, primarily consisting of limestone, silty shale, and black shale, has been rarely studied but recently showed promising results for shale gas exploration. Geochemical investigations of the upper section shale deposits revealed that the organic matter enrichment mechanism underwent dynamic changes due to relative sea-level changes and episodic upwelling activities.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Xin Wang, Chen Zhang, Zixin Xue, Qianyou Wang, Zhenxue Jiang, Kun Zhang, Xiangye Kong
Summary: This study analyzed the heterogeneity of gas compositions and the effects of magmatism on gas accumulation in shale gas exploration in the Yangtze plate. The results showed that magmatism caused the development of micro-fractures in shale reservoirs and accelerated the thermal evolution rate of organic matter. The impact of magmatism on shale gas accumulation varied in different regions, either favoring or compromising efficient gas accumulation in shale reservoirs.
JOURNAL OF ASIAN EARTH SCIENCES
(2024)