The distinctive trace elements signature of the less-evolved MORB materials in the south of Birjand ophiolites

Mafic rocks including basalts and gabbros are the main constituents of Birjand ophiolites. They are found in several places and show low grade metamorphism in the field and under the microscope. Chondrite-normalized REE patterns for basalts and gabbros indicate that these rocks are transitional-enriched to depleted mid-oceanic ridge basalts respectively. Otherwise, N-MORB normalized trace elements patterns for basalts and gabbros are considered to be enriched in some LIL elements. Depletion in Ti and also in Nb (in gabbros) is other characteristic of these rocks. Therefore an incomplete short-lived subduction regime for generation of those heterogeneities can be suggested. The primary mantle-normalized trace elements pattern for Birjand harzburgite also confirms some LIL enrichments.