Nguyen Hoang , Tran Thi Huong , Ryuichi Shinjo , Le Duc Anh , Le Duc Luong , Phan Dong Pha
{"title":"Geochemistry of late Miocene-Pleistocene basalts from a coastal area of Vietnam: Implication for small-scale mantle heterogeneities","authors":"Nguyen Hoang , Tran Thi Huong , Ryuichi Shinjo , Le Duc Anh , Le Duc Luong , Phan Dong Pha","doi":"10.1016/j.jseaes.2025.106488","DOIUrl":null,"url":null,"abstract":"<div><div>This study presents a comprehensive analysis of late Miocene to Pleistocene basaltic samples collected from a coastal area of central Vietnam. The investigation involved various analytical methods, including eruption age determination, petrographic examination, geochemical characterization, and assessment of Sr-Nd-Hf-Pb isotopic compositions. The sampled basalt types include silica-undersaturated mantle xenolith-bearing basalts (∼1 Ma), olivine-bearing phyric alkaline, and sub-alkaline basalts (∼7 to 1 Ma). These basalt varieties display typical intraplate geochemistry and a wide range of radiogenic isotope variations, indicating mantle and crustal influences. Interestingly, despite these variations, there is no evidence of crustal contamination. Spatial analysis reveals distinct differences in geochemical and isotopic signatures across the sampled areas, suggesting spatial controls on mantle source composition. The isotopic compositions align with depleted mantle (DM) and enriched mantle types 1 and 2 (EM1 and EM2), closely associating with the Indian DUPAL lead isotopic signature. The localized heterogeneity within the subcontinental lithospheric mantle (SCLM) is attributed to metasomatism from mafic lenses or magmatic melts from the asthenosphere. Furthermore, elemental characteristics resembling typical ocean island basalts and elevated Pb and Sr isotopic ratios suggest a potential involvement of ancient, subducted sediments within the mantle.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"281 ","pages":"Article 106488"},"PeriodicalIF":2.7000,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Asian Earth Sciences","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1367912025000045","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
This study presents a comprehensive analysis of late Miocene to Pleistocene basaltic samples collected from a coastal area of central Vietnam. The investigation involved various analytical methods, including eruption age determination, petrographic examination, geochemical characterization, and assessment of Sr-Nd-Hf-Pb isotopic compositions. The sampled basalt types include silica-undersaturated mantle xenolith-bearing basalts (∼1 Ma), olivine-bearing phyric alkaline, and sub-alkaline basalts (∼7 to 1 Ma). These basalt varieties display typical intraplate geochemistry and a wide range of radiogenic isotope variations, indicating mantle and crustal influences. Interestingly, despite these variations, there is no evidence of crustal contamination. Spatial analysis reveals distinct differences in geochemical and isotopic signatures across the sampled areas, suggesting spatial controls on mantle source composition. The isotopic compositions align with depleted mantle (DM) and enriched mantle types 1 and 2 (EM1 and EM2), closely associating with the Indian DUPAL lead isotopic signature. The localized heterogeneity within the subcontinental lithospheric mantle (SCLM) is attributed to metasomatism from mafic lenses or magmatic melts from the asthenosphere. Furthermore, elemental characteristics resembling typical ocean island basalts and elevated Pb and Sr isotopic ratios suggest a potential involvement of ancient, subducted sediments within the mantle.
期刊介绍:
Journal of Asian Earth Sciences has an open access mirror journal Journal of Asian Earth Sciences: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review.
The Journal of Asian Earth Sciences is an international interdisciplinary journal devoted to all aspects of research related to the solid Earth Sciences of Asia. The Journal publishes high quality, peer-reviewed scientific papers on the regional geology, tectonics, geochemistry and geophysics of Asia. It will be devoted primarily to research papers but short communications relating to new developments of broad interest, reviews and book reviews will also be included. Papers must have international appeal and should present work of more than local significance.
The scope includes deep processes of the Asian continent and its adjacent oceans; seismology and earthquakes; orogeny, magmatism, metamorphism and volcanism; growth, deformation and destruction of the Asian crust; crust-mantle interaction; evolution of life (early life, biostratigraphy, biogeography and mass-extinction); fluids, fluxes and reservoirs of mineral and energy resources; surface processes (weathering, erosion, transport and deposition of sediments) and resulting geomorphology; and the response of the Earth to global climate change as viewed within the Asian continent and surrounding oceans.