The association of barite veins with acid igneous and metamorphic rocks
It was observed that barite veins are invariably associated with acid igneous rocks whether Plutonic or volcanic and certain metamorphic rocks which tend to be acidic in composition. The present investigation tries to explain on chemical basis why does this association occur in nature. The associate...
Elmentve itt :
| Szerzők: | |
|---|---|
| Dokumentumtípus: | Cikk |
| Megjelent: |
University of Szeged, Department of Mineralogy, Geochemistry and Petrology
Szeged
1982
|
| Sorozat: | Acta mineralogica-petrographica
25 No. 2 |
| Kulcsszavak: | Kőzettan, Ásványtan, Földtan |
| Tárgyszavak: | |
| Online Access: | http://acta.bibl.u-szeged.hu/24695 |
| Tartalmi kivonat: | It was observed that barite veins are invariably associated with acid igneous rocks whether Plutonic or volcanic and certain metamorphic rocks which tend to be acidic in composition. The present investigation tries to explain on chemical basis why does this association occur in nature. The associated acid igneous and metamorphic rocks like granite, granodiorite, porphyrite and gneiss are all characterised by being rich in potash feldspar and biotite, in other words they are feldspar-mica rocks. These two minerals are known to be enriched in the element Ba. Weathering processes release Ba in solution. Once in solution, Ba migrates veinward to regions of sulfate in order to form the well known barite veins. Another mechanism of forming barite veins depends on the fact that there is considerable Ba mobility and enrichment during metasomatism and granitization. This mobility with the presence of free S04 2 " radical will help in formation of barite veins characteristic of granitized zones. Magmatic hydrothermal fluids are shown here to be deprived from any significant amount of Ba. Thus hydrothermal origin usually attributed to many barite veins ought to be replaced by a mechanism based on either of the two mentioned models. |
|---|---|
| Terjedelem/Fizikai jellemzők: | 157-161 |
| ISSN: | 0365-8066 |