ISSN:
1432-0967
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract 21 samples of spilitic rocks of Devonian to Carboniferous age from NW-Germany have been analyzed for major elements, a large group of minor elements and the modal mineral composition. Their major element and mineral composition is comparable to Recent spilites from oceanic ridges. Major emphasis has been given to the absolute and relative abundance of the lanthanides and yttrium. Their pattern, which is most probably not altered during processes of spilitization is that of tholeiitic basalts occuring on the continents and in oceanic islands. Spilitization of the rocks under investigation is explained as a metamorphic process in a partially open system (loss of Si, Ca, and gain of H2O, CO2, Na) in a temperature range from 200° to about 400° C. Most abundant new minerals are: albite and chlorite; basaltic relict minerals are: plagioclase (high in Ca) and diopsidic pyroxene. Minerals typical for the temperature range mentioned are: prehnite, pumpellyite, actinolithe, epidote biotite. Microprobe analyses of several typical minerals are listed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00373309
