Abstract:

Ben Tuan granite blocks belong to the Long Dai structure, and Da Le block belongs to the Da Nang - Se Kong structure zone. At present, most of the studies arranged rocks of two blocks into the Ba Na complex that is Kreta age. Research results show that the two intrusional blocks have relatively different lithological and mineral characteristics. Accordingly, Ben Tuan block appears granite rocks to be rich in pegmatite lumps and orthite, sphen minerals. The results of U - Pb zircon age determined by SHRIMP method for Ben Tuan block granitoid is 244.5 ± 1.5 Ma (T2), the Da The block is 427 ± 2.4 Ma (D1) shows that these two intrusive bloks are not the same as the intrusive magma complex, formed in different techtonic structures. The magmatic formations of Da The block are closely related to Caledonia mountain setting, and the magmatic ones of the Ben Tuan block are related to Indosini mountain setting. The results of this study is of great significance in the interpretation of the Truong Son and Da Nang - Se Kong mountain belt during the Paleozoic - Mesozoic period in the context of the tectonic setting in Southeast Asia