Petrology, Geochemistry and Mineral Chemistry of Neoproterozoic Granitoids, Wadi Zaghra, Southern Sinai, Egypt

Abstract

Wadi Zaghra granitoid intrusion comprises quartz diorite, granodiorite, tonalite, monzogranites, syenogranite, and alkali feldspar granites. Geochemically, Zaghra granitoid rocks are peraluminous magma and exhibit a transitional calc-alkaline to alkaline magma type affinity of I type, as well as island arc setting belonging to the volcanic arc regime. Microprobe data of amphiboles are calcic-type and have the composition of actinolite, actinolite hornblende, magnesio-hornblende, and edenite. Biotites are Mg-rich and meroxene types. Plagioclase has a composition of albite and oligoclase fields with minor andesine. According to mineral chemistry, Wadi Zaghra granitoid rocks crystallized at an average pressure of about 1.4 Kb and a temperature range of 650-700 °C.