Szczegóły publikacji
Opis bibliograficzny
Petrogenesis of scapolite-rich gabbro from the alkaline Cho Don complex in north-eastern Vietnam - mineralogical and geochemical implications / Magdalena DUMAŃSKA-SŁOWIK, Tomasz POWOLNY, Giang Nguyen Khac, Wiesław HEFLIK, Magdalena Sikorska-Jaworowska // Lithos ; ISSN 0024-4937. — 2020 — vol. 374–375 art. no. 105703, s. 1–15. — Bibliogr. s. 13–15, Abstr. — Publikacja dostępna online od: 2020-07-23
Autorzy (5)
- AGHDumańska-Słowik Magdalena
- AGHPowolny Tomasz
- Khac Giang Nguyen
- AGHHeflik Wiesław
- Sikorska-Jaworowska Magdalena
Słowa kluczowe
Dane bibliometryczne
ID BaDAP | 129681 |
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Data dodania do BaDAP | 2020-09-07 |
Tekst źródłowy | URL |
DOI | 10.1016/j.lithos.2020.105703 |
Rok publikacji | 2020 |
Typ publikacji | artykuł w czasopiśmie |
Otwarty dostęp | |
Creative Commons | |
Czasopismo/seria | Lithos |
Abstract
A unique scapolite-rich gabbro has been found in the Cho Don complex (north-eastern Vietnam) and investigated using cathodoluminescence microscopy and spectroscopy, electron-microscopic observations, and Raman micro-spectroscopy. The scapolite, occupying up to ca. 30 vol% of rock matrix, displays distinctive brownish to greenish (S2_activated) luminescence, while its chemical composition is marked by the enrichment in Ca (~Me73–80) and CO2 (~4.60 wt%). Meionitic scapolite is accompanied by such magmatic phases as: clinopyroxenes (partially altered to uralite), oligoclase-andesine, K-feldspars, biotite, as well as fluorapatite and titanite. On the basis of micro-textural observations and phase-relations including interstitial form of scapolite, the high Ca content relative to adjacent Na-rich plagioclase and high-angle contacts between pyroxenes and scapolites, it may be inferred that the investigated Me-scapolite represents a high-temperature igneous phase. The presence of wollastonite, vesuvianite and calcite within the rock matrix gives a clue to the interaction between parental melt and country rocks that could act as a source for the formation of a specific CO2-enriched magma. Furthermore, scapolite breaks down into: (1) intergrowths of Ca-rich plagioclase with worm-like calcite that may reflect isobaric cooling following the high-temperature stage of rock evolution, and (2) prehnite-vuagnatite clusters, which in turn correspond to the late-stage low-temperature hydrothermal alteration. The formation of the latter could be induced by alteration of primary clinopyroxenes due to the release of Ca2+ and Ti4+. According to major and trace element data of whole-rock samples, the scapolite-rich gabbro originated from slightly evolved alkaline melt, but also shows enrichment in LREE relative to HREE ([La/Yb]CN ~ 10.24), as well as strong depletion in Nb-Ta-Ti relative to U and Th content. These geochemical signatures point to the enriched lithospheric mantle source of parental magma, which is likely to have been imprinted by subduction components (possibly sediment-derived melts) and/or crustal contamination.