Browsing by Author "Afzali, Ahmad Omid"

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Geology, Petrographic Characteristics and Tectonic Structure of Paleoproterozoic Basement of Kabul Block (north Eastern Afghanistan), Initial Findings
(2022) Kansun, Gürsel; Afzali, Ahmad Omid
The Paleoproterozoic basement of Kabul Block is a cratonic basement in north eastern Afghanistan. Precambrian Kabul Block including metamorphic rocks only takes place at the base of the study area. The Neo-Proterozoic Welayati formation overlies the Paleo-Proterozoic Sherdarwaza formation with a tectonic contact, and they both overlay Khair Khana formation. In the region, Alghoi meta granitoid intruded into both Khair Khana and Sherdarwaza formations. The Khair Khana formation contains of granulites, granitic gneisses ve amphibolites. The mineral assemblages of granulites are plagioclase + quartz + K-feldspar + orthopyroxene + clinopyroxene (diopside/augite). Granitic gneisses are observed as hornblende gneiss, garnet-biotite gneiss and pyroxene-gneiss. Hornblende-gneisses include hornblende + quartz + K-feldspar mineral assemblage, garnet-biotite gneisses are evident with plagioclase + quartz + K-feldspar + biotite (red) + garnet mineral assemblage, and pyroxene gneisses include quartz + plagioclase + biotite + clinopyroxene mineral assemblage. Amphibolites consist of hornblende + plagioclase + quartz ± zoisite ± sphene ± ilmenite ± apatite mineral assemblage. The Sherdarwaza formation contains marbles, amphibolites, biotite gneisses, micaschists and migmatites. Marbles consist of calcites ± quartz ± apatite. In amphibolites, harnblende + plagioclase + quartz ± epidote ± zoisite ± garnet mineral assemblage are observed. Biotite gneisses include plagioclase + quartz + microcline + biotite ± sphene ± apatite ± zircon mineral assemblage. Micachists consist of quartz + plagioclase + microcline + biotite ± sphene ± apatite mineral assemblage. Migmatites include plagioclase + quartz + microcline +biotite ± sphene ± apatite mineral assemblage. Alghoi meta granitoid is generally observed as stocks and small masses, and sometimes it shows foliation. It consists mainly of meta granites. The meta granites that show granular texture include plagioclase + quartz + K-feldspar + biotite + hornblende. The Welayeti formation contains quartzite, kyanitegarnet-staurolite schist, garnet-mica schist, kyanite-garnet-mica schist and garnet-muscovite schist. Quartzite include quartz ± muscovite ± biotite. They are observed hornblende + quartz + plagioclase ± garnet ± epidote ± zoisite ± rutile ± magnetite in amphibolites. Kyanite-garnet-staurolite schists are evident with staurolite + kyanite + garnet + mica + biotite + quartz + plagioclase ± apatite ± epidote ± ilmenite ± monazite mineral assemblage. Garnet-mica schists and kyanite-garnet-mica schists include quartz + plagioclase + biotite + muscovite + kyanite + garnet ± chlorite ± apatite ± tourmaline ± sphene ± rutile. In garnet-muscovite schists, muscovite + quartz + plagioclase + garnet ± tourmaline ± apatite ± zircon are observed. The granulites in Kabul Block are together with granite gneisses, and they can be separated under one formation. Granulites show different mineral compositions, Usually, they are without garnet, in some cases they include garnet. The amount of plagioclase is higher in them according to other rocks. In some cases, the composition of granulitesis very similar to that of quartz mangarites that indicates high temperature and pressure of the metamorphism process and shows that this block is related to a segment of Columbia and Rodinia supercontinents during Paleoproterozoic collisional events.
The Stratigraphic and Petrographic Characteristics of Metamorphites of Alanya Unit, and the Porphyroblast - Foliation Relationships in Sugözü Complex (middle Nappe), Anamur-Mersin
(2020) Kansun, Gürsel; Koçak, Kerim; Afzali, Ahmad Omid; Öztürk, Alican; Delikan, Arif; Delikan, Selma; Işık, Ali Fuat
The study area is located in the southern part of the Central Taurus in Anamur (Mersin) vicinity. The Alanya Unit consisting of completely metamorphites consists of threeimbricate metamorphic nappes. Lower-Middle Cambrian aged the Mahmutlar group (lower nappe) is composed of widespread mica schists containing crystallized limestone, cherty dolomite, quartzite interlevels and greenschist lenses. Precambrian aged Sugözü complex (middle nappe) contains kyanite-sillimanite-staurolite mica schists and widespread garnet-mica schists, which contain greenschist-amphibolite-amphibol schist bands-lenses and metagabro-metadiabase dykes-interlevels. In the middle nappe, Cambrian and Permian blocks belonging to Alanya Unit are observed. The Yumrudağ group (upper nappe) begins with Lower-Middle Cambrian aged mica schists containing cherty dolomite, crystallized limestone, quartzite interlevels and greenschist lenses. Higher up with an unconformity pass into the Upper Permian aged alternation of quartz schist - calc schist - crystallized limestone - phyllite and thick bituminous crystallized limestone containing greenschist lenses. Barite, copper and galenite formations take place in upper nappe lithologies (Ağzıkara formation). Upper Paleocene - Middle Eocene aged Kötekler formation unconformably overlies the Alanya Unit. Alanya Unit has been subjected to multi-stage deformations in connection with intense tectonic movements. Especially, biotite (brown, green) + muscovite + garnet (prop-almandine-grossular) + quartz ± chlorite (ripidolite-picnochlorite, pennin-clinochlore) ± kyanite ± staurolite ± sillimanite + plagioclase (albite-oligoclase-andesine) ± epidote ± zoisite/clinozoisite ± orthoclase + tourmaline (green, brown) ± graphite ± sphene ± rutile ± apatite mineral paragenesis are observed in metapelitic and metasemipelitic rocks belonging to Sugözü complex (middle nappe). Amphibolites and amphibole schists of this complex contain hornblende (tchermacite, ferro-tchermacite, magnesio-hornblende and edenite) + garnet + plagioclase (albite-oligoclase-andezine) ± relic clinopyroxene (augite-pigeonite) + chlorite (ripidolite, clinochlore) ± orthoclase ± epidote ± zoisite/clinozoisite ± biotite (green, brown) ± actinolite ± muscovite ± quartz ± calcite ± sphene ± apatite ± rutile mineral assemblage. Hornblende (tchermacite, ferro-tchermacite) + plagioclase (albite-oligoclase-andesine) + relic clinopyroxene (augite) ± garnet + quartz + chlorite (ripidolite, pennin-clinochlore) ± actinolite ± zoisite/clinozoisite ± epidote ± calcite ± sphene ± apatite is observed in metagabbros and metadiabases. The greenschists are characterized by tremolite + actinolite + chlorite (ripidolite-picnochlorite) + plagioclase (albite) ± garnet + zoisite / clinozoisite + epidote ± quartz ± microcline ± relic clinopyroxene (augite) ± calcite + sphene ± apatite mineral assemblage. Especially when the index minerals, different mineral paragenesis and deformation-metamorphism relations within the Sugözü complex take into account, it has been seen that Alanya unity underwent three phases of metamorphism which follow one another.
The Stratigraphic and Petrographic Properties of the Rocks in Davut – Tazekent Vicinity, Diyadin-Ağrı
(2020) Kansun, Gürsel; Afzali, Ahmad Omid; Üçgün, Fatih
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.
Stratigraphy and Petrographical Properties of the Kazdağ Massif Metamorphites in the North of Güre-Çamlıbel, Edremit-Balıkesir
(SETSCI, 2019) Kansun, Gürsel; Afzali, Ahmad Omid; Ökmen, Gülçin
The study area covers Kaz Mountain and its surroundings which is located in the north of Güre, Çamlıbel and Arıtaşı Neighborhoods of Edremit District of Balıkesir Province. The Kazdağ Massif which is estimated to be of Paleozoic primitive age starts with the Fındıklı formation in the lower part. This formation is composed of hornblende gneiss, biotite-hornblende gneiss, epidote-hornblende gneiss, epidote-biotite gneiss, garnet-biotite gneiss, garnet-hornblende gneiss, disten-garnet-mica schist and disten-garnet-biotite schist which show alternation with crystallized limestones (Altınoluk marble member). In the upper part of the Fındıklı formation, there are crystallized limestones (Babadağ marble member). Tozlu formation which is tectonically overlain Fındıklı formation consists of amphibolite – amphibole schist (amphibolite member), metadunite – metaproxenite – metaproxenhornblendite - serpentinite (metaophiolite member) and crystallized limestones (marble member) with lateral-vertical transition with each other. Sarıkız formation is observed with an unconformity on Tozlu formation. Sarıkız formation starts with the thin gneiss level in the lower part, and upwards, higher up pass into thick crystallized limestones with calcschist interlevels. In the upper part Sütüven formation which is observed tectonically is composed of mica gneiss - sillimanite-biotite gneiss - hornblende-biotite gneiss including granitic gneiss (granitic gneiss member) - amphibolite - marble bands and lenses. The anatexis ve migmatite is sometimes observed in Sütüven formation. The mineral assemblage which consist of hornblende (tschermakite, edenite and barroisite) + plagioclase (albite-oligoclaseandesine) + quartz ± orthoclase + biotite (brown, green) + garnet (prop-almandine-grossular) ± epidote ± zoisite / clinozoisite ± chlorite (ripidolite-picnochlorite, penninite-clinochlore) ± kyanite ± staurolite + muscovite ± calcite ± sillimanite ± microcline + tourmaline (green, brown) + sphene ± rutile ± apatite are observed in amphibole gneisses and biotite gneisses which constitute the dominant lithology of Fındıklı formation. The disten-garnet-mica schist and disten-garnet-biotie schist which are observed in the upper part of fındıklı formation show the mineral assemble which consist of biotite (brown) + quartz + garnet (propalmandine-grossular) + kyanite + sillimanite + plagioclase (albite-oligoclase-andesine) ± muscovite + chlorite (ripidolitepicnochlorite, penninite-clinochlore) ± epidote ± zoisite / clinozoisite + orthoclase + tourmaline (green) ± sphene ± rutile ± apatite. The mineral assemblage which consist of plagioclase (albite-oligoclase-andesin) + quartz ± orthoclase + biotite (brown and green) ± sillimanite + hornblende (tschermakite) ± garnet (prop-almandine-grossular) ± epidote ± zoisite / clinozoisite ± chlorite (ripidolite-picnochlorite, penninite-clinochlore) + muscovite ± kyanite ± calcite ± staurolite ± microcline + tourmaline (green, brown) + sphene ± rutile ± apatite are observed in mica gneiss, sillimanite-biotite gneiss and hornblende-biotite gneiss which constitute the dominant lithology of Sütüven formation. The amphibolites which are located as interlevels in this formation are evident with the mineral assemblage which consist of hornblende (tschermakite) + plagioclase (albite-oligoclase-andesine) ± biotite (brown) ± quartz ± epidote ± zoisite / clinozoisite ± chlorite (ripidolite-picnochlorite, penninite-clinochlore) + sphene. The granitic gneisses belonging to Sütüven formation show the mineral assemblage which consist of plagioclase (albiteoligoclase-andesine) + orthoclase + quartz + biotite (brown) ± hornblende (tschermakite) + garnet (prop-almandine-grossular) ± chlorite (ripidolite-picnochlorite, penninite-clinochlore) ± epidote ± zoisite / clinozoisite + sphene ± rutile ± apatite. That both the mineral paragenesis in different metamorphism conditions is observed in the metapelitic-metasemipeliticmetabasic rocks which are located in especially the Fındıklı and Sütüven formations of the Kazdağ Massif and this massif has exposed to metamorphism with multi-stage as a result of dense tectonic movements indicate that this massif has undergone metamorphism of least three stage.
Stratigraphy of the Kuloğlu–yaka Area and Petrographic Properties of Boyabat Metamorphites and Volcanic-Pyroclastic Rocks of Yemişliçay Formation, the Boyabat-Sinop
(SETSCI, 2019) Kansun, Gürsel; Afzali, Ahmad Omid; Usta, Gülşah
The study area is located between Kuloglu and Yaka Villages in the north of Boyabat District of Sinop Province. Paleozoic-Triassic aged Boyabat metamorphites are observed at the bottom of the study area. These metamorphites are composed of phyllite, sericite-chlorite schist and metasandstones which contain intense greenschist, glaucophanitic greenschist, metagabbro and metadiabase interlevels at the bottom levels. This unit is overlain unconformably by the Lower Jurassic aged Akgöl formation, which consists of alternation of sandstone-milestone-shale. Higher up, Middle-Upper Jurassic aged Bürnük formation which consist of conglomerate is observed unconformably. The Bürnük formation is overlain by the lateral-vertical transition by Middle-Upper Jurassic aged the Akkaya formation which contain limestones. The Lower Cretaceous aged Çağlayan formation, which is composed of marls and shales with sandstone-sandy limestone interlevels, unconformably overlies the Akkaya formation. Higher up, Upper Cretaceous aged Kapanboğazı formation which consist of cherty limestones and micritic limestones is observed unconformably. This formation is conformably overlain by the Upper Cretaceous aged Yemişliçay formation which consists of basaltic-andesitic lavas, tuffs and agglomerates which contain sandstone-marl interlevels. At the top, the Upper Cretaceous aged Cankurtaran formation, which consist of alternation of sandstone-marl-shale-mudstone-limestone and contain tuff-agglomerate interlevels at the bottom levels, is conformably observed. The following mineral assemblages have been observed in metapelitic, metapsammitic and metabasic rocks belonging to Boyabat metamorphites. Phyllites and sericite-chlorite schists contain mineral assemblage which are composed of sericite + chlorite (ripidolite-picnochlorite) + quartz  calcite  plagioclase (albite)  muscovite  epidote  zoisite / clinozoisite  microcline  biotite (green)  sphene. The mineral assemblage which are composed sericite + quartz + muscovite  epidote  plagioclase (albite)  microcline  chlorite  calcite  biotite (green)  apatite are observed in metasandstones. The mineral assemblage observed in greenschists are tremolite + actinolite + chlorite (ripidolite-picnochlorite) + plagioclase (albite) + epidote + zoisite / clinozoisite  quartz  calcite  microcline  relict clinoproxene (diopside / augite) + sphene. Glaucophanitic greenschists observed as interlevels and sometimes blocks in metapelitic schists show mineral assemblage which are composed of chlorite + glaucophane + epidote + plagioclase (albite) + phengite  actinolite + zoisite / clinozoisite  stilpnomelane  calcite  quartz + sphene. Metagabbro and metadiabases consist of mineral assemblages which are composed of actinolite + plagioclase (albite-oligoclase) + chlorite (penninite-clinochlore)  relict clinoproxene (diopside / augite)  zoisite / clinozoisite + quartz  epidote  sphene. Boyabat metamorphites initially underwent to metamorphism in quartz-albite-muscovite-biotite subfacies of greenschist facies at 425-450 oC temperature and 2-3 kbar pressure conditions. Later, these metamorphites underwent the second metamorphism in the glaucophanitic greenschist (epidote-blueschist) facies at 400-500 oC temperatures and 6-12 kbar pressure conditions with increased pressure in the environment. The effects of these metamorphism are observed in the metabasites within the Boyabat metamorphites. Basalts and basaltic andesites belonging to the Yemişliçay formation show aphanitic porphyritic texture. Basalts contain common plagioclase and olivine phenocrysts and plagioclase microliths. The phenocrystalline phase of basaltic andesites consists of plagioclase, clinoproxen (diopside/augite) and very few olivine. Plagioclase microlites and volcanic glass are observed in matrix of these rocks. The tuffs observed in Yemişliçay formation include plagioclase, clinoproxene (diopside augite), amphibole (hornblende), volcanic glass and litic fragments. These rocks are andesitic tuff “according to composition and grain size” and lapilli stone “according to grain size” and lapilli tuff and lapilli stone “according to% distribution of grains” and vitric tuff “according to the volcanic glass-crystal-litic fragments compound.