N. A. Rashidnejad Omran; A. A. Fattahi; F. Masoudi
Abstract
The late Eocene post-collisional Khoshoumi- Dar-Anjir intrusive complex consist of two adjacent Khoshoumi granite and Dar Anjir diorite plutons in Saghand area, located in 120 km northeast of Yazd in Central Iran structural zone. This complex intruded within high-grade metamorphic rocks of Chapedony ...
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The late Eocene post-collisional Khoshoumi- Dar-Anjir intrusive complex consist of two adjacent Khoshoumi granite and Dar Anjir diorite plutons in Saghand area, located in 120 km northeast of Yazd in Central Iran structural zone. This complex intruded within high-grade metamorphic rocks of Chapedony Complex. Syenogranite, monzogranite, granodiorite, tonalite and quartzdiorite constitiue its lithologies. Aplitic and micromonzonitic to microdioritic dikes crosscutting the entire body. Hybrid rocks and mafic microgranular enclaves with various shapes and sizes are widely seen in this complex. Geochemical investigations show that these rocks are metaluminous to moderately peraluminous, magnesian and high- K calc- alkaline I- and A-type granitoids. Chonderite- normalized REE patterns of both plutons and related dikes display intra-elemental fractionation (2.72 >(La/Yb)N >41.64) and concentration of LREE and Eu negative anomalies (ave Eu/Eu*= 0.63). Trace elements behavior represent depletion in Nb, Ti, P and enrichment in K, Rb, Ba and Th that could be assigned to mafic magma contamination by crustal materials. Their tectonic setting match with Volcanic Arc Granites (VAG) and Within Plate Granites (WPG). Petrographical, geological and tectonomagmatic characteristics of this intrusive complex are very similar to high- K calc- alkaline granites (KGC) and like most of them, fractional crystallization and mafic – felsic magma mixing play significant role in its evolution and petrogenesis.
