Szczegóły publikacji
Opis bibliograficzny
Agates from Western Atlas (Morocco) – constraints from mineralogical and microtextural characteristics / Jaroslav PRŠEK, Magdalena DUMAŃSKA-SŁOWIK, Tomasz POWOLNY, Lucyna NATKANIEC-NOWAK, Tomasz TOBOŁA, Damian Zych, Dominika Skrępnicka // Minerals [Dokument elektroniczny]. — Czasopismo elektroniczne ; ISSN 2075-163X. — 2020 — vol. 10 iss. 2 art. no. 198, s. 1–15. — Wymagania systemowe: Adobe Reader. — Bibliogr. s. 12–15, Abstr. — Publikacja dostępna online od: 2020-02-22
Autorzy (7)
Słowa kluczowe
Dane bibliometryczne
| ID BaDAP | 128164 |
|---|---|
| Data dodania do BaDAP | 2020-04-02 |
| Tekst źródłowy | URL |
| DOI | 10.3390/min10020198 |
| Rok publikacji | 2020 |
| Typ publikacji | artykuł w czasopiśmie |
| Otwarty dostęp |  |
| Creative Commons | |
| Czasopismo/seria | Minerals |
Abstract
Agate samples collected from the vicinity of Asni and Agouim (Western Atlas, Morocco) were investigated using microscopic observations supported by Raman micro-spectroscopy. The agates are marked by the presence of various microtextures typical of epithermal vein deposits, including jigsaw-puzzle, feathery, and lattice-bladed. The first two indicate that the formation of agates was likely marked by recrystallization of metastable silica phases (i.e., opaline silica or massive chalcedony). The presence of lattice-bladed (after barite and calcite) quartz may be, in turn, ascribed to the boiling-related conditions that could have triggered the formation of abundant copper and iron sulfides found within silica matrix. Additionally, the local occurrence of growth lines (so-called Bambauer quartz) and intergrowth of length-slow and length-fast chalcedony are linked to the variations of physico-chemical conditions during rock formation (alkaline-acidic). According to Raman spectroscopy, silica matrix of the agates is made of alpha-quartz with a local admixture of moganite (from 0.0 up to 78 wt.%), but also contains numerous solid inclusions of hematite, celadonite, as well as poorly-organized carbonaceous material and rutile. These phases were likely emplaced during low-temperature hydrothermal activity of SiO2-bearing fluids that originated from post-magmatic hydrothermal activity developed within host rocks and/or meteoric waters.
