- Tytuł:
- Geochemical variations within the Upper Oligocene-Lower Miocene lava succession of Úhošt Hill (NE margin of Doupovské hory Mts., Czech Republic)
- Autorzy:
-
Rapprich, V.
Holub, V. F. - Powiązania:
- https://bibliotekanauki.pl/articles/2060213.pdf
- Data publikacji:
- 2008
- Wydawca:
- Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
- Tematy:
-
Úhošď Hill
Doupovské hory Mts.
lava-flow succession
basalt
picrobasalt
ankaramite - Opis:
- Purely effusive activity built up a sequence of nine lavas on Úhoš' Hill. The oldest erupted lavas are tephrites/basanites (28.66 ± 1.06 Ma) and are of slightly evolved character. These are overlain by more differentiated alkali basalt. The succession continues with picrobasaltic lavas rich in phenocrysts (ankaramites 26.38 ± 1.04 Ma). The entire succession is crowned by alkali ba alt lavas (22.09 ± 0.73 Ma). All lavas appear to be emitted from a common conduit. With respect to geochemical and isotopic data, how ever, the studied sequence could not be interpreted in terms of the exhausting of a simple magma chamber. We propose the role of a more complex reservoir or, of two independent reservoirs attached to a single conduit system. The tephrites/basanites and picrobasalts (ankaramites) are closely related, the latter being derived by accumulation of mafic phenocrysts, namely clinopyroxene. The bas alts form an other group differing from the tephrites/basanites and picrobasalts in more evolved isotopic compositions of Sr and Nd as well as in in compatible-elementratios. The isotopic composition of the lavas seems to reflect mixed man tle sources derived from the European Asthenospheric Reservoir through the addition of components similar to Enriched Mantle (EM 1 and EM 2). The basalts originated by fractionation of different magma batches that contained a higher proportion of the enriched mantle component(s) or that were more contaminated with crustal material.
- Źródło:
-
Geological Quarterly; 2008, 52, 3; 253-268
1641-7291 - Pojawia się w:
- Geological Quarterly
- Dostawca treści:
- Biblioteka Nauki
Artykuł