Geochemistry and petrology of rift-related mafic sills and arc-related Gabbro–Diorite bodies, Northern Bafq District,Central Iran  

作　　者：S.M.Niktabar N.Rashidnejad Omran 

机构地区：[1]Department of Geology, Tarbiat Modares University

出　　处：《Acta Geochimica》2018年第2期180-192,共13页地球化学学报（英文）

摘　　要：Two types of mafic intrusions have been recognized in the north of the Bafq district, Central Iran. A number of olivine-gabbroic to gabbroic sills intruded the Rizu Formation, comprised of alternating carbonate and volcanic rocks. Mineralogical data show that olivine + pyroxene +brown amphibole(kaersutite) + calcic plagioclase +opaque comprise the olivine-gabbroic rocks, and intermediate(or sodic) plagioclase + altered pyroxene and altered amphibole to biotite + opaque minerals the gabbroic rocks.Both rock types have shown within-plate and alkaline characters and have been presumed to be related to rift formation. The mafic-alkaline magma source of the sills is proposed to have been derived from enriched mantle.Regionally, two Gabbro–Diorite intrusions have been identified in the metamorphic complexes. Mineralogical data suggest that the pyroxene + amphibole(hornblende) +plagioclase + biotite + opaque minerals formed the gabbro to diorite intrusions. These rocks have shown characteristics of calc-alkaline and volcanic arc magmatism.Two types of mafic intrusions have been recognized in the north of the B afq district, Central Iran. A number of olivine-gabbroic to gabbroic sills intruded the Rizu Formation, comprised of alternating carbonate and volcanic rocks. Mineralogical data show that olivine ＋ pyroxene ＋ brown amphibole （kaersutite） ＋ calcic plagioclase ＋ opaque comprise the olivine-gabbroic rocks, and intermediate （or sodic） plagioclase ＋ altered pyroxene and altered amphibole to biotite ＋ opaque minerals the gabbroic rocks. Both rock types have shown within-plate and alkaline characters and have been presumed to be related to rift formation. The mafic-alkaline magma source of the sills is proposed to have been derived from enriched mantle. Regionally, two Gabbro-Diorite intrusions have been identified in the metamorphic complexes. Mineralogical data suggest that the pyroxene ＋ amphibole （hornblende）＋ plagioclase ＋ biotite ＋ opaque minerals formed the gabbro to diorite intrusions. These rocks have shown characteristics of calc-alkaline and volcanic arc magmatism.

关 键 词：SILLS Rizu formation RIFT Volcanic arc 

分 类 号：P588.12[天文地球—岩石学]