Davut – Tazekent Civarındaki Kayaçların Stratigrafik ve Petrografik Özellikleri, Diyadin-Ağrı-Türkiye

The study is located in vicinity of Taşbasamak, Tazekent, Davut, Boyalan, Kuşburnu and Ulukent villages in the south of Diyadin district of Ağrı city. In the study area, Paleozoic aged Batıbeyli metamorphites which consist of crystallized limestones which contain calc-schist interlevels are observed at the bottom. The Upper Miocene aged Alibonca formation composed of conglomerate, trachyandesitic tuff-agglomerate, sandy limestone, marl, dolomite-dolomitic limestone and lacustrine limestone are located unconformably on these metamorphites. Upper Miocene aged Sekirdağ volcanites consisting of dacitic - rhyodacitic tuffs, agglomerates and lavas are observed by lateral - vertical transition over the Alibonca formation. Higher up, Lower Pliocene aged Solhan volcanites are composed of alkaline basaltic lavas are observed. The Solhan volcanites are covered by Upper Pliocene aged Hamur volcanites consisting of trachyandesitic lava and ignimbrite. Higher up, Upper Pliocene-Pleistocene aged Kale pyroclastics consisting of lapilli tuff, ash, volcanic bomb, slag and agglomerate with alkaline basalt composition are observed. These pyrolastics are covered by Upper Pliocene-Pleistocene aged Tutak volcanites which are composed of alkaline basalts. At the top, travertine and alluvium are found. Calcite + dolomite ± quartz ± muscovite mineral paragenesis is observed in metacarbonates belonging to Batıbeyli metamorphites. The tuffs belonging to the Kuşburnu pyroclastic member include quartz, plagioclase, sanidine, clinopyroxene (diopside/augite), biotite, amphibole (hornblende), sphene, opaque mineral, volcanic glass and litic fragment. These tuffs were named as lapillistone and ash tuff “according to grain size”, trachyandesite tuff “according to composition and grain size”, lapillistone, ash tuff and lapilli tuff “accoding to percentage distribution of grains” and vitric tuff “according to glass-crystals-lithic fragments composition”. The tuffs of Sekirdağ volcanites contain quartz, plagioclase, sanidine, biotite, amphibole (hornblende), opaque mineral, volcanic glass and litic fragment. The dacitic and rhyodacitic lavas belonging to these volcantecs include quartz, plagioclase, sanidine, biotite, amphibole (hornblende), opaque mineral, plagioclase microlites and volcanic glass. Tuffs belonging to Sekirdağ volcanites were named as lapillistone and ash tuff “according to grain size”, rhyodacitic tuff and dacitic tuff “according to composition and grain size”, lapillistone and ash tuff “according to percentage distribution of grains” and vitric tuff “according to glass-crystals-lithic fragments”. Alkaline basalts of Solhan volcanites include quartz, olivine, clinopyroxene (diopside/augite), apatite, opaque mineral and plagioclase microlites. Plagioclase, sanidine, amphibole (hornblende), clinopyroxene (diopside/augite), apatite, opaque mineral, plagioclase and sanidine microlites are observed in trachyandesites belonging to Tazekent trachyandesite member. Plagioclase, hornblende, clinopyroxene, sanidine, pumice fragments, litic fragments and volcanic glass are located in ignimbirites belonging to Dalören ignimbirite member. The tuffs of Kale pyroclastics include plagioclase, clinopyroxene (diopside/augite), olivine, opaque mineral, volcanic glass and litic fragment. Agglomerates of Kale pyroclastics include plagioclase, olivine, clinopyroxen (diopside/augite), orthopyroxen (enstatite), apatite, opaque mineral, volcanic glass and litic fragment. These tuffs were named as lapillistone “according to grain size”, basaltic tuff “according to composition and grain size”, lapilli tuff “according to percentage distribution of grains” and vitric tuff “according to glass-crystals-lithic fragments composition”. The agglomerate is in basaltic agglomerate composition “according to composition and grain size”. Alkali basalts belonging to Tutak volcanites include plagioclase, olivine, clinopyroxen (diopside/augite), orthoproxen (enstatite), apatite, opaque mineral and plagioclase microlites.