Article
Geochemistry & Geophysics
Marian B. Holness, Madeleine C. S. Humphreys, Olivier Namur, Jens C. O. Andersen, Christian Tegner, Troels F. D. Nielsen
Summary: The mush on the vertical walls of the Skaergaard Intrusion reached a maximum thickness of about 180 m and was highly unstable, with continuous material loss and episodic collapse events. This study highlights the significance of vertical walls in supplying loose material for the formation of mobile magmatic slurries.
JOURNAL OF PETROLOGY
(2022)
Article
Geosciences, Multidisciplinary
Niccolo Satta, Giacomo Criniti, Alexander Kurnosov, Tiziana Boffa Ballaran, Takayuki Ishii, Hauke Marquardt
Summary: Experimental results show that hydrous MORB is less dense but has faster aggregate seismic velocities compared to anhydrous MORB, opposite to other lithologies. Hydration of MORB increases the seismic contrast with the background mantle.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Tushar Mouli Chakraborti, Kosuke Kimura, Arijit Ray, Gautam Kumar Deb, Ramananda Chakrabarti
Summary: The discovery of dismembered cumulate and layered mafic-ultramafic rocks within a mobile belt assemblage in the Singhbhum Craton region of India is enigmatic and may have far-reaching implications for geology. The geochemical composition and isotopic characteristics of the gabbroid and serpentinized wehrlite rocks suggest complex fluid-rock interactions and formation in a magma chamber or oceanic environment. The presence of these oceanic crustal fragments in the Chaibasa intra-continental rift basin indicates rift-drift transition and possible obduction events during the Paleoproterozoic era.
PRECAMBRIAN RESEARCH
(2021)
Article
Geosciences, Multidisciplinary
Sashimeren Imtisunep, Athokpam Krishnakanta Singh, Rajkumar Bikramaditya, Shoraisam Khogenkumar, Monika Chaubey, Naveen Kumar
Summary: Mafic extrusive and intrusive rocks from the Nagaland-Manipur Ophiolite in north-east India were studied to understand their magmatic evolution in different tectonic environments. The results showed that they were derived from two different mantle sources, one from a plume and the other from a subduction zone mantle wedge.
GEOLOGICAL JOURNAL
(2022)
Article
Geochemistry & Geophysics
Mohammad Reza Ghorbani, Hossein Mahmoudi, Fatemeh Sepidbar, Matthias Barth, Mohamed Zaki Khedr, Naoyoshi Iwata, Ryuichi Shinjo, Parham Ahmadi
Summary: The Sawlava ophiolite on the Iran-Iraq border represents remnants of the Cenozoic southern Neo-Tethys Ocean. The study of the ophiolite reveals that the volcanic rocks have different compositions and heterogeneity, possibly recording magmatic activity and plate movements.
Review
Geology
Thungyani Ovung, Biswajit Ghosh, Jyotisankar Ray
Summary: The study of peridotites and volcanic rocks from the Indo-Myanmar Ranges (IMR) ophiolites revealed the source and extent of mantle melting, as well as the impact of subduction components on modifying melt composition. Partial melting in the rocks was found to be 5-25% from a depleted MORB mantle source, while the addition of fluids from a subducting slab and melts from subducting sediments have influenced the composition of IMR volcanics.
INTERNATIONAL GEOLOGY REVIEW
(2021)
Article
Geochemistry & Geophysics
J. Escuder-Viruete, M. Castillo-Carrion, F. Perez Valera, P. Valverde-Vaquero, A. Rubio Ordonez, F. J. Fernandez
Summary: The Rio Boba mafic-ultramafic plutonic sequence in northern Dominican Republic represents the lower crust of the Caribbean island arc. It is formed by cumulate rocks derived from tholeiitic magmas with low H2O content. The magmatic evolution involves multi-stage processes, including decompressional melting of a refractory mantle source and enrichment by a hydrous fluid derived from a subducting slab and/or overlying sediments.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2022)
Article
Geosciences, Multidisciplinary
Changfeng Liu, Zhiguang Zhou, Guosheng Wang, Chen Wu, Hongying Li, Shiwei Ma
Summary: The Xingmeng Orogenic Belt underwent multiple episodes of subduction and accretion during a long-lived orogeny, with a debate on its Late Paleozoic tectonic evolution. This study presents geochemical, geochronological, and isotopic data on strongly peraluminous granites and gabbro-diorites in the region, suggesting they may have originated from partial melting of heterogeneous sources. The findings support a ridge subduction model for the tectonic architecture of the Sunidzuoqi-Xilinhot region.
GEOSCIENCE FRONTIERS
(2021)
Article
Geosciences, Multidisciplinary
Xiawei Zhang, Yingjie Li, Genhou Wang, Shuai Wang, Xingrui Kong, Xiaodong Wang, Zhibin Liu
Summary: Investigating intra-oceanic subduction is crucial for understanding plate tectonic processes and continental growth. A newly discovered early Permian gabbro occurrence in the Diyanmiao ophiolite zone provides important evidence of intra-oceanic subduction in the Paleo-Asian Ocean. The characteristics and geochemical composition of the gabbro suggest its formation during the initial stage of intra-oceanic subduction and indicate that the Paleo-Asian Ocean was still undergoing subduction in the early Permian.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Geochemistry & Geophysics
Shengbiao Yang, Jingsui Yang, Jian Zhang, Ruibao Li, Dongyang Lian, Fahui Xiong, Chuqi Cao, Fei Liu, Hui Zhao
Summary: The study of the Xigaze ophiolite in Tibet provides evidence of the tectonic processes that formed the Neotethyan Ocean. Through geological, mineralogical, and geochemical analysis, the researchers determined that the ophiolite represents an ancient oceanic lithosphere formed during the Early Cretaceous. The findings offer new insights into the diversity of melt evolution in the forearc crust.
Article
Geochemistry & Geophysics
Abbas Asiabanha, Jacques-Marie Bardintzeff, Kobra Shayegh
Summary: The Nourabad-Dinavar ophiolitic complex in western Iran is a fragment of the Neo-Tethys oceanic lithosphere. It has undergone static and dynamic metamorphism and is related to the island-arc regime based on whole-rock chemical data. The mineral chemistry analysis confirms its classification as a MORB-type ophiolite emplaced in the supra-subduction zone. Geochemical modeling reveals the successive magmatic processes involved in its evolution. The emplacement history of the ophiolite complex can be divided into an obduction stage and an exhumation stage.
MINERALOGY AND PETROLOGY
(2023)
Article
Geosciences, Multidisciplinary
Bingqian Ding, Fuping Pei, Jingyang Wei, Wenliang Xu, Zhiwei Wang, Tianjiao Sang
Summary: This study presents new geochronological, geochemical, and isotopic data for igneous rocks in Jilin Province, revealing the evolution of an Early Paleozoic island arc belt. The results suggest the presence of both mid-ocean ridge basalt (MORB)-type and arc-type rocks in the studied area, representing different crustal evolution settings.
Article
Geochemistry & Geophysics
Kan Li, Long Li
Summary: Uptake of nitrogen during hydrothermal alteration of oceanic crust makes it a significant N reservoir. However, the N characteristics of moderate- to high-temperature altered gabbroic oceanic crust have been rarely studied. Through analyzing the N concentrations and isotope compositions of gabbroic rocks from three oceans, it was found that they have similar N characteristics to altered basalts and mainly derive from seawater. These findings are crucial for calculating global N input flux and modeling N quantities released to the deep mantle.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Geosciences, Multidisciplinary
Salim Akhtar, Priyanka Negi, Ashima Saikia
Summary: The study focuses on the mafic cumulate rocks of the Andaman ophiolite, specifically olivine-bearing and olivine-free gabbros in the Kodiaghat and Munda Pahar area of South Andaman Island. The geochemistry and mineral compositions suggest a hybrid signature of island arc tholeiite (IAT) - mid-oceanic ridge basalt (MORB), indicating formation in an oceanic back-arc and oceanic arc setting in the Late Cretaceous. Geochemical modelling shows that trapped melt fractions of 0%-20% can produce the observed trace element signatures of these gabbros.
CANADIAN JOURNAL OF EARTH SCIENCES
(2021)
Article
Engineering, Marine
Tianxiao Ji, Zhigang Zeng
Summary: This paper presents new data on the major elements, trace elements, and Nd-Hf isotopes of south mid-Atlantic ridge (SMAR) MORBs. The geochemical characteristics, including enrichment of fluid-mobile elements and anomalous trace element ratios, suggest that these MORBs have been modified by subduction.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)