Geological Characteristics And Its Tectonic Significance Of The Paleozoic Volcanic Rocks In Bogda-harlik

This article focuses on petrological, geochemical perspective go on systematic dicussfor Paleozoic volcanic Rock in Bogda-Harlik erea, while the combination of thedistribution of volcanic rocks, forming environment and the formation of the era werediscussed and comprehensive understanding. With analysis and comparative study ofgeochemical data provide an important basis for the evolution of Paleozoic geologicalresearch in the area.The area is mainly composed of Ordovician, Silurian, Devonian, Carboniferous,Permian volcanic rocks in Harlik of eastern area and Carboniferous volcanic rocks inBogda of western area. The volcanic rocks are calc-alkaline series in Harlik of easternregion, The volcanic rocks are mainly calc-alkaline series and are a small amount ofalkaline series in Bogda of western region. Regional stratigraphy, geochronology andpaleontological data indicate that the volcanic rocks in region formed in the Paleozoic;Volcanic rock assemblages are basalts-basaltic andesite-andesite-dacite-rhyolite;volcanic rocks enriched in REE, large-ion lithophile element (LILE),and depleted in Nb,Ta, Ti, high field strength elements (HSFE). Rock assemblages and geochemistry showthat the Paleozoic volcanic rocks in the region has the geochemical properties ofcontinental margin volcanic arc of volcanics rocks, its magma source shall be subject topartial melting of subducted oceanic plate accountable lithospheric mantle wedge. Theingredients polar character of Paleozoic volcanic rocks in the Bogda-Harlik impliedoceanic basin of Kangguer was northward subduction in Paleozoic of this area and formedHarlik Ordovician-Silurian volcanic arc, to the Carboniferous, Bogda-Harlik becomeback arc zone of volcanic arc properties.