Petrology of the Kurancali phlogopitic metagabbro an Island arc type ophiolitic sliver in the Central Anatolian Crystalline Complex

Date

2002-06-01

Author

Toksoy Köksal, Fatma
Yalınız, Mustafa Kenan

Metadata

Show full item record

Item Usage Stats

113
views

0
downloads

In the Central Anatolian Crystalline Complex (CACC), besides the ophiolitic bodies with more or less recognisable sequence and preserved magmatic pseudostratigraphy, there are many massive and layered gabbroic masses occurring as isolated outcrops. Most of these mafic rocks were interpreted as dismembered parts of an allochthonous ophiolitic assemblage (Yaliniz et al, 2000), derived from the northerly located Izmir-Ankara branch of the Alpine Neotethys. An overall supra-subduction zone genesis has been envisaged for the Central Anatolian Ocean (CAO). However, remarkable differences in the geochemical characteristics of different isolated outcrops suggest differences in the source areas and tectonic settings within the intra-oceanic subduction zone. One of these gabbro units, the Kurancali Metagabbro, occurs as an isolated body in the central part of CACC. It is thrust along a steep south vergent thrust-plane onto the uppermost units of the Central Anatolian Metamorphics (CAM). The main body of the Kurancali Metagabbro is characterised by a distinct compositional layering. The layered gabbros are represented by pyroxene and hornblende gabbros. Phlogopite-rich plagioclase-hornblende gabbro occurs mainly as pegmatitic dikes intruding the layered gabbro sequence. The layered gabbros in general consist mainly of diopsidic augites, brown hornblendes, plagioclase. Secondary phases are phlogopitic mica, brownish green hornblende replacing clinopyroxenes, and fibrous greenish actinolitic hornblende partially or completely replacing brown hornblende. The primary dark micas display phlogopitic composition within the range of annite30.13-42.60 and plogopite 69.9-57.4 The analysed pyroxenes are diopsidic (En32.3Fs18.5Wo49.1 - En34.9Fs17.9Wo48.2). The whole-rock geochemistry of the gabbros indicates the presence of two distinct groups of rocks; a subordinate group of phlogopite gabbro with island arc calc-alkaline affinity and a dominating layered gabbro sequence with island arc tholeiite characteristics. They are extremely enriched in LIL elements, indicative of an alkaline metasomatism in the source region and they display geochemical features of transitional back arc basin basalts (BABB)/island arc basalts (IAB)- and IABtype oceanic crust. Based on their geochemical similarities with modern island arc basements, we suggest that the Kurankali Metagabbro may represent the basement of an initial island arc, generated in a supra-subduction zone setting within the Izmir-Ankara branch of Neotethys.

URI

https://hdl.handle.net/11511/76999

Journal

Ofioliti

Collections

Unverified, Article

Suggestions

OpenMETU
Core

Petrology of the Kurancali phlogopitic metagabbro: An island arc-type ophiolitic sliver in the Central Anatolian Crystalline Complex Toksoy-Köksal, Fatma; Göncüoğlu, Mehmet Cemal; Yalınız, Mustafa Kenan (2001-07-01) The Kurancali metagabbro occurs as an isolated body in the central part of the Central Anatolian Crystalline Complex. It has been emplaced along a steep S-vergent thrust-plane onto the uppermost units of the Central Anatolian Metamorphics. The main body of the Kurancali metagabbro is characterized by distinct compositional layering. The layered gabbros comprise pyroxene and hornblende gabbros. Phlogopite-rich, plagioclase-hornblende gabbro occurs mainly as pegmatitic dikes intruding the layered gabbro seque...
Petrology of the Eocene volcanism in the central anataolia: implication for the early tertiary evolution of the Central Anatolian crystalline complex Geneli, Fatma; Güncüoğlu, M. Cemal; Kuşcu, Gonca; Department of Geological Engineering (2011) In the Central Anatolian Crystalline Complex (CACC) the Late Cretaceous post-collisional granitic magmatism is followed by Eocene extension, resulting in formation of roughly E-W trending transtensional basins. Formation of these basins was accompanied by calc- alkaline- mildly alkaline volcanism. The volcanic rocks, mainly subaques lava flows and subareal domes are concentrated along these basins and associated with Middle Eocene (Bartonian) Mucur Formation. They are basic to intermediate and are classifie...
Petrology and geotectonic significance of plagiogranite from the Sarikaraman Ophiolite (Central Anatolia, Turkey) Yaliniz, MK; Floyd, PA; Göncüoğlu, Mehmet Cemal (2000-06-01) Plagiogranites within the supra-subduction zone (SSZ) type Saikaraman Ophiolite (SO), Central Anatolia, are very fine to coarse grained leucocratic rocks with a range of occurrences as simple narrow fracture infilling to wide complex zones of net-veining or agmatites with numerous, partly assimilated enclaves of gabbro and dolerite. Petrographically, they are characterized by the textures ranging from hypidiomorphic granular to granophyric intergrowths of quartz and plagioclase. Geochemically, major and tra...
Petrological reconstruction of Triassic seamounts/oceanic islands within the Palaeotethys: Geochemical implications from the Karakaya subduction/accretion Complex, Northern Turkey Sayıt, Kaan; Göncüoğlu, Mehmet Cemal (2010-10-01) Subduction/accretion complexes provide unique insight into the tectonic assembly of continental margins and oceanic basins, as they record the tectonic stacking and juxtaposition of materials derived from distinct tectonic environments. The Karakaya Complex, exposed throughout northern Turkey, is a good example of an ancient subduction/accretion complex that includes a number of pre-Liassic units that characterize the closure of Palaeotethys. Defining the components of this complex is of crucial importance ...
Extrusive members of postcollisional A-type magmatism in Central Anatolia: Karahidir Volcanics, Idis Dagi-Avanos Area, Turkey Koksal, S; Göncüoğlu, Mehmet Cemal; Floyd, PA (2001-08-01) The Idis Dagi Igneous Complex is one of a number of late-stage plutonic bodies within the Central Anatolian Crystalline Complex. It intrudes Paleozoic-Mesozoic metamorphic basement rocks and Late Cretaceous granitoids. The complex comprises mainly quartz syenites and alkali-feldspar quartz syenites known as the Idis Dagi Syenitoids.

Citation Formats

F. Toksoy Köksal and M. K. Yalınız, “Petrology of the Kurancali phlogopitic metagabbro an Island arc type ophiolitic sliver in the Central Anatolian Crystalline Complex,” Ofioliti, pp. 75–76, 2002, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/76999.