U-Pb dating was conducted for zircons from a total of 14 samples from 13 granite bodies in southwestern Cambodia using LA-ICP-MS. The granitic rock samples were collected from southwestern Cambodia, southwest of the Mae Ping Fault extending from northwest Cambodia via Tonle Sap Lake to southern Vietnam. The studied rock bodies belong to the ilmenite-series, except for three granitic rock bodies. They were identified as I-or A-type. The analysis yielded three distinct age ranges: 295-309, 191-232, and 75-98 Ma. The 295-309 Ma ages are associated with the Paleo-Tethys Sea subduction beneath the Indochina Block. The ages of 191-232 Ma may correspond to the amalgamation period of the Sibumasu and Indochina Blocks during the Indosinian Orogeny. Granitic rocks with ages of 75-98 Ma occur near the southeastern Cambodia-southern Vietnam border. Formation of these granitic rocks was associated with the Paleo-Pacific Ocean Plate (the Izanagi Plate) subduction beneath the Indochina Block. The region in which these granitic rocks occur is part of the Dalat-Kratie Zone.
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http://dx.doi.org/10.1016/j.heliyon.2023.e19734 | DOI Listing |
Environ Sci Pollut Res Int
January 2025
Department of Agricultural Chemistry, National Taiwan University, Taipei, 106319, Taiwan.
Rare earth elements (REEs) are emerging contaminants rendering potential risks in soils to environmental quality and human health. The causation between their geochemical signatures and contamination levels with parent rocks and soil properties are critical for REEs risk assessments, which are urgently needed globally. Thus, this study aimed to elucidate cause-and-effect among hydrofluoric-acid-digested total and ethylenediaminetetraacetic acid extracted bioavailable soil REEs and their contamination degree evaluated by pollution indices in 268 soil layer (horizon) samples from 50 soil profiles derived from felsic, intermediate, mafic, ultramafic, and sedimentary rocks in Taiwan.
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January 2025
LECIV - Civil Engineering Laboratory, UENF - State University of the North in Rio de Janeiro, Av. Alberto Lamego, 2000, Campos dos Goytacazes, Rio de Janeiro, 28013-602, RJ, Brazil.
The correct choice of a stone aggregate for railway ballast is directly related to the stability, safety, efficiency, and maintenance costs of the track. The aggregate must meet several criteria to ensure it is the most appropriate material. Thus, the present study aimed to evaluate four distinct stones: two granites, a diabase, and a basalt, all mined in the eastern region of the state of São Paulo, Brazil, regarding their applicability as ballast.
View Article and Find Full Text PDFEnviron Geochem Health
January 2025
Korea Institute of Geoscience and Mineral Resources, Daejeon, 34132, Republic of Korea.
Long-term intake of high-fluoride water can cause fluorosis in bones and teeth or damage to organs. Fluoride in groundwater is primarily derived from reactions with rocks containing fluorine-related minerals, and fluoride concentrations are elevated in groundwater that has been reacting with these rocks for a long time. The purpose of this study is to investigate the origin and distribution of fluoride in groundwater and to assess the influence of various factors, including geology, on fluoride concentrations in groundwater.
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January 2025
Xincheng Gold Mine of Shandong Gold Mining Co., Ltd., Laizhou, 261400, Shandong, China.
The creep failure of rocks is related to its microstructure, external loading and time. A nonlinear yield model was introduced to describe the variation in the cohesion and friction angle with plastic strain and intergranular stress. The mechanical properties and creep characteristics of deep granite were obtained by indoor tests, and a variable radius particle clump model was constructed based on the particle flow method.
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January 2025
Physics Department, Faculty of Science, Fayoum University, Fayoum, Egypt.
For the purpose of this study, four natural rock samples-namely, diorite, granodiorite, tonalite, and granite-are being investigated about their radiation attenuation. The elemental composition of the rocks was obtained through Energy dispersive X-ray spectroscopy (EDX) which examines the microstructural and localized area elemental analyses of the four rock samples. A Monte Carlo simulation (MCNP) was used to determine and evaluate the investigated samples.
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