当前位置：
X-MOL 学术
›
Solid Earth
›
论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Contribution of carbonatite and recycled oceanic crust to petit-spot lavas on the western Pacific Plate
Solid Earth ( IF 3.4 ) Pub Date : 2024-02-08 , DOI: 10.5194/se-15-167-2024 Kazuto Mikuni , Naoto Hirano , Shiki Machida , Hirochika Sumino , Norikatsu Akizawa , Akihiro Tamura , Tomoaki Morishita , Yasuhiro Kato
Solid Earth ( IF 3.4 ) Pub Date : 2024-02-08 , DOI: 10.5194/se-15-167-2024 Kazuto Mikuni , Naoto Hirano , Shiki Machida , Hirochika Sumino , Norikatsu Akizawa , Akihiro Tamura , Tomoaki Morishita , Yasuhiro Kato
Abstract. Petit-spot volcanoes, occurring due to plate flexure, have been reported globally. As the petit-spot melts ascend from the asthenosphere, they provide crucial information of the lithosphere–asthenosphere boundary. Herein, we examined the lava outcrops of six monogenetic volcanoes formed by petit-spot volcanism in the western Pacific. We then analyzed the 40Ar/39Ar ages, major and trace element compositions, and Sr, Nd, and Pb isotopic ratios of the petit-spot basalts. The 40Ar/39Ar ages of two monogenetic volcanoes were ca. 2.6 Ma (million years ago) and ca. 0 Ma. The isotopic compositions of the western Pacific petit-spot basalts suggest geochemically similar melting sources. They were likely derived from a mixture of high-μ (HIMU) mantle-like and enriched mantle (EM)-1-like components related to carbonatitic/carbonated materials and recycled crustal components. The characteristic trace element composition (i.e., Zr, Hf, and Ti depletions) of the western Pacific petit-spot magmas could be explained by the partial melting of ∼ 5 % crust bearing garnet lherzolite, with 10 % carbonatite flux to a given mass of the source, as implied by a mass-balance-based melting model. This result confirms the involvement of carbonatite melt and recycled crust in the source of petit-spot melts. It provides insights into the genesis of tectonic-induced volcanoes, including the Hawaiian North Arch and Samoan petit-spot-like rejuvenated volcanoes that have a similar trace element composition to petit-spot basalts.
更新日期：2024-02-09
京公网安备 11010802027423号