Tectonics setting of sedimentary facies in the Kopet-Dagh Basement

رخساره‌های رسوبی

مقاله 3، دوره 2، شماره 1، شهریور 1388   

نوع مقاله: بدون عنوان

شناسه دیجیتال (DOI): 10.22067/sed.facies.v2i1.2071

نویسنده

فرزین قائمی^*

چکیده

Detrital sedimentary rocks of the Agh-darband area with Paleozoic to Late Triassic age, the only exposure of the Kopet-Dagh basement, consist of three zones. 1- Paleozoic metamorphic rocks that have been deposited in deep marine environment of continental slope by turbidity flow. 2-Qara-gheitan Formation has maximum outcrop in Agh-Darband area. Based on sedimentary structures, this formation formed as debris flow and sheet flood within braided stream systems in proximal area, flowing from North to South. Qara-gheitan conglomerates have volcanic sources. Magmatic debris fragments are calk-alkaline granodiorite to tonalite and volcanic debris fragments are high potassic calk-alkaline rhyolite to dacite. Petrological studies show that these rocks are "I- type". These plutonic and volcanic fragments in Qara-gheitan conglomerates had a source from a magmatic arc north of Agh-darband which is now buried under the young sediments. 3-Sina Formation is composed of a sequence of shale and sandstone that formed in continental slope by classic turbidites. All sandstone of Qara-gheitan and Sina Formations are lithic arkose to feldspatic litharenite that originate from dissected to transitional arc. Detrital sedimentary rocks of Paleozoic to Late Triassic age that formed the basement rocks of the Kopet-Dagh formed in foreland basin that also formed in a front of magmatic arc.