Article
Geochemistry & Geophysics
Fatemeh Sepidbar, Seyed Masoud Homam, Guanghui Wu, Robert Moritz, Hamid Hafezimoghadas
Summary: This study provides detailed petrological, geochronological, geochemical, Sr-Nd isotope, and mineral chemical data on basalt and gabbro from the Binaloud zone in the Alborz. The results suggest that these rocks were formed at 461.8 +/- 8.2 and 435.0 +/- 4.5 Ma, respectively, and were likely produced by mantle plume activity mixed with enriched sub-continental lithospheric mantle components. The findings also indicate that the subduction of the Tornquist oceanic lithosphere was followed by plume activity, continental rifting, and the opening of the Paleo-Tethys during the Silurian period.
Article
Geochemistry & Geophysics
Arathy Ravindran, Klaus Mezger, S. Balakrishnan, Jasper Berndt
Summary: The study suggests that early mantle differentiation and rapid formation of oceanic and continental crust may have led to the chemical heterogeneity of the Archean mantle. Analysis of isotopes in basaltic and ultramafic rocks reveals the involvement of different parts of the mantle in the formation and evolution of the mantle, providing important clues for geologists.
Article
Geochemistry & Geophysics
He Liu, Yiran Wang, Jianghong Deng, Yu Zhang, Qian Chen, Renqiang Liao, Wei-dong Sun
Summary: Research shows that modern-style subduction and corresponding arc magmatism started globally around 2.2 billion years ago, coinciding with the onset of the supercontinent cycle. Continuous subduction of cold oceanic lithosphere not only leads to arc magmatism along active margins, but also accelerates the cooling rate of the mantle, reducing the widespread distribution of intermediate-felsic rocks derived from crustal delamination and slab melting.
Article
Geosciences, Multidisciplinary
R. Fischer, L. Ruepke, T. Gerya
Summary: Research suggests that the formation of TTG crust undergoes growth and overturn phases, characterized by the formation of low- and medium-pressure TTG linked to Moho depth, and high-pressure TTGs requiring a different mechanism.
Article
Geosciences, Multidisciplinary
George L. Guice, Sophie R. Miocevich, Hannah S. R. Huges, Iain McDonald, Kathryn M. Goodenough, Michael R. Ackerson, John M. MacDonald, John W. Faithfull
Summary: This study investigates four ultramafic-mafic bodies in the Lewisian Gneiss Complex (LGC) of northwest Scotland and identifies distinct petrological characteristics, shedding light on the formation and evolution of the LGC. The findings suggest that the LGC may consist of either a continuous piece of Archean crust or multiple geologically distinct Archean terranes.
PRECAMBRIAN RESEARCH
(2022)
Article
Geochemistry & Geophysics
Nao Nakanishi, Igor S. Puchtel, Richard J. Walker, Peter I. Nabelek
Summary: This study examines the positive W-182 anomalies in the upper mantle using Neoarchean and Paleoproterozoic rocks from the Black Hills in South Dakota, USA. The research finds that the anomalies decreased and nearly disappeared by the end of the Archean, likely due to mantle mixing processes. The specific mechanism behind this process needs further exploration through geodynamical modeling.
Article
Geochemistry & Geophysics
Seyed Ali Akbar Asadi, Habibollah Ghasemi, Fatemeh Sepidbar, Mohsen Mobasheri, Yuruo Shi, Richard M. Palin
Summary: The nature and formation of the Sikhoran ultramafic-mafic complex in southwest Iran is still debated. The complex is composed of various rocks and may have a polygenetic origin with different tectonic settings. The study suggests that the complex formed at different times and may have been influenced by processes such as mantle plume melting and oceanic subduction.
Article
Geochemistry & Geophysics
Sampriti Basak, Eric Hasenstab, Santanu Kumar Bhowmik, Axel Gerdes, Somnath Dasgupta, Carsten Muenker, Gr. Ravindra Kumar, Sumit Chakraborty
Summary: Studying high-grade metamorphic rocks in a crustal-scale shear zone can provide insights into the Archean tectonic processes. Petrological investigations reveal different compositions and reaction histories of these rocks. By using thermobarometry, phase equilibria modeling, and geochronology, a multi-stage P-T-t history was reconstructed, suggesting an early form of peel-back styled orogenesis and intracrustal differentiation.
JOURNAL OF PETROLOGY
(2023)
Review
Geosciences, Multidisciplinary
Aubreya Adams
Summary: The Cameroon Volcanic Line (CVL) of west Africa, which exhibits asynchronous volcanism along the line, poses challenges to common models of mantle processes and volcanic system genesis. Geophysical studies have been conducted to understand the complex geology of the region and potential geodynamic models for the CVL formation.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geology
Johnny Seales, Adrian Lenardic, Julian Garrido Tomasini
Summary: Petrological data suggests that plate tectonics started 2.5 billion years ago, with Earth being a single-plate planet before that time. However, our study shows that plate tectonics has been continuously operating throughout geological history.
Article
Environmental Sciences
Dengliang Gao
Summary: The westward drifting and southward tapering of the South American continent have influenced the asymmetry and non-uniformity in the opening of the South Atlantic. It is revealed that non-uniform seafloor spreading caused the migration of ridges and hotspots, leaving behind nonlinear seamount trails. These findings are significant for understanding the geodynamics of global plate tectonics.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Aurovinda Panda, D. Srinivasa Sarma, Rahul Patel
Summary: The Paleoproterozoic mafic dykes from central Bastar craton exhibit characteristics of basaltic composition, tholeiitic magma series, and crustal contamination. The generation of the magma is supported by interactions between plume and subduction-modified lithospheric mantle. The turbulent ascent of the magma is indicated by Reynolds numbers calculated from quantitative calculations of the dyke widths.
JOURNAL OF EARTH SYSTEM SCIENCE
(2022)
Article
Geochemistry & Geophysics
E. G. Grosch, S. Ndlela, D. Murphy, N. McLoughlin, J. Trubac, J. Slama
Summary: This study presents the first whole-rock Lu-Hf isotope analyses of mafic-ultramafic rocks in the Kromberg type-section of the Barberton greenstone belt. The analysis, together with major and trace element data, helps identify different volcanic rock types and provides insights into their formation environments. The highly dynamic and variable mantle melting environments are reflected in the major and trace element geochemistry.
Article
Geochemistry & Geophysics
Sheng-Zhu Zhu, Xiao-Long Huang, Fan Yang, Peng-Li He
Summary: The study in the Wajilitag area of the western Tarim Large Igneous Province shows that early Permian mafic-ultramafic rocks have characteristics closely related to Fe-Ti-oxide deposits, providing important clues for understanding the relationships among mantle source, magmatism, and metallogenesis.
Article
Geochemistry & Geophysics
Ozgur Karaoglu, Fuat Erkul, Sibel Tatar Erkul, Michele Lustrino
Summary: A 400m thick Middle-Late Triassic volcano-sedimentary succession is exposed near Antalya Gulf, SW Turkey. The majority of the succession consists of volcanic and subvolcanic rocks, associated with breccia, turbiditic sediments, chert, and limestone layers. The igneous rocks are alkali basalts and are considered as precursors of a rift system. Numerical simulations suggest the presence of two magma chambers, one shallow and one deeper, which can explain the distribution of the volcanic rocks in the region.