Abstract
The Late Proterozoic rocks of the Wadi El-Imra district of the Central Eastern Desert, Egypt, comprise a metagabbro-diorite complex (oldest) and Older and Younger Granitoid complexes. Trace element characteristics show that the basic and granitoid rocks are of calc-alkaline affinity, but some of the Younger Granitoids grade into alkaline granites. The ºNd values of the the basic and granitoid rocks range from +8.3 to +4.9, and Nd model ages are younger or rather similar to crystallization ages. These data suggest a predominant depleted mantle derivation, indicating formation by subduction in an oceanic setting. REE patterns of the granitoid rocks suggest different modes of petrogenesis. This, coupled with the occurrence of amphibolite xenoliths in the Older Granitoids, may indicate that some of these rocks represent partial melts from basic rocks that have been amphibolitized at deep crustal levels of the oceanic arc.
- © Geological Society of London 1996
Please note that if you are logged into the Lyell Collection and attempt to access content that is outside of your subscription entitlement you will be presented with a new login screen. You have the option to pay to view this content if you choose. Please see the relevant links below for further assistance.