Geochemical investigation of olivines from alkali basalt and their xenolithes (Nógrád-Gömör region, Hungary)
Neogene-Quaternary alkaline basalts in the Nógrád-Gömör region bear several kinds of inclusions and xenocrysts: Olivine appears in both the Iherzolitic and wehrlitic series of the inclusions, is frequent among xenocrysts and appears in the host alkaline basalts as phenocrysts and in the groundmass....
Elmentve itt :
| Szerzők: | |
|---|---|
| Dokumentumtípus: | Cikk |
| Megjelent: |
University of Szeged, Department of Mineralogy, Geochemistry and Petrology
Szeged
1987
|
| Sorozat: | Acta mineralogica-petrographica
29 |
| Kulcsszavak: | Kőzettan, Ásványtan, Földtan, Geokémia |
| Tárgyszavak: | |
| Online Access: | http://acta.bibl.u-szeged.hu/24756 |
| Tartalmi kivonat: | Neogene-Quaternary alkaline basalts in the Nógrád-Gömör region bear several kinds of inclusions and xenocrysts: Olivine appears in both the Iherzolitic and wehrlitic series of the inclusions, is frequent among xenocrysts and appears in the host alkaline basalts as phenocrysts and in the groundmass. Deformation lamellae and subgrain boundaries in xenocrysts and in a wehrlite sample indicate a complex history of the inclusion before embedding in the host alkaline basalt. The REEpoor olivine with the highest mg-value is characteristic for lherzolite and dunite inclusions of the upper mantle origin. Main element composition of the xenocrysts is similar to that of the wehrlitic series (cumulate). Their mg-values indicate crystallization from a Fe-rich, tholeiitic magma; magma mixing (possibly assimilation) caused their embedding in the host alkaline basalt. REE spectra of individual grains suggest cognate phenocrysts and groundmass olivines from the alkaline basalts. High mg-values of phenocrysts indicate crystallization in the upper mantle, while groundmass olivines are products of near-surface process. |
|---|---|
| Terjedelem/Fizikai jellemzők: | 35-46 |
| ISSN: | 0365-8066 |