Spatial distribution and origin of mantle heterogeneity in the Oman ophiolite: evidence from basal peridotites

Abstract

Basal peridotites above the amphibolitic metamorphic sole outcropped around Wadi Sarami in central Oman ophiolite are the best example to understand the spatial extent of mantle heterogeneity and to examine peridotites-slab interactions. We recognized two types of lherzolites (A, B). The type-A lherzolites, being strongly foliated, lie directly above the sole and are overlain and/or surrounded by type B ones that are massive. Both lherzolites and harzburgites are similar in chemical properties to that observed for the abyssal peridotites. In type-A lherzolites, clinopyroxenes show higher contents in Al₂O₃ (up to 7.3 wt%), Na₂O (1.2 wt%),