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Xenocrysts in Eocene Camptonites from Taourirt, Northern Morocco

1988; Cambridge University Press; Volume: 52; Issue: 368 Linguagem: Inglês

10.1180/minmag.1988.052.368.04

1471-8022

Abdelkader Mokhtari, Danielle Velde,

Geochemistry and Elemental Analysis

Abstract A study of xenocrystic material included in 57 Ma igneous rocks that outcrop in the Taourirt area of north-east Morocco has been made. The mineralogy of the host rocks is essentially clinopyroxene, rare olivine, titanomagnetite and either kaersutite or biotite. Feldspars (plagioclase and alkali feldspar) and nepheline are usually altered. Accessories may include haüyne, perovskite and ferriannite-rich annite. The complex xenocrystic assemblage includes various types of clinopyroxene, amphiboles, micas of differing compositions and various types of spinel. These inclusions did not dissolve in the melt and, as a consequence, the residual (alkali-rich) mineralogical assemblage is not modified. Their abundance is such that they may not significantly affect the major element compositions, but they may strongly influence the levels of certain trace elements such as Cr and Ni.