Geochemistry and petrogenesis of the oceanic island and subduction-related assemblages from the palaeotethyan Karakaya subduction/accretion complex, central and nw Turkey

Sayıt, Kaan
The Nilüfer Unit of the Karakaya Complex at the pre-Liassic basement of the Sakarya Composite Terrane is composed mainly of metabasaltic lithologies with limestones, and minor cherts and mudstones. These metabasic assemblages show OIB- and E-MORB-type geochemical signatures with variable enrichment in the most incompatible elements relative to N-MORB. The Eymir Unit consists of variably deformed metaclastics, and constitutes the matrix in which the Nilüfer-type blocks are embedded. In the Ankara region, the Eymir Unit is intruded by metadiabase dikes that display intra-oceanic SSZ-type signatures with a marked negative Nb anomaly combined with a slightly depleted HFSE budget relative to N-MORB. The wide range in trace element ratios displayed by the Nilüfer metabasic rocks can be explained by melt-mixing processes that has taken place within the spinel-garnet transition zone. Pb-Nd-Hf radiogenic isotope systematics reveal that the Nilüfer samples has been derived from enriched mantle sources, and a multi-component source mixing is required to explain their genesis. The Eymir metadiabases, however, require contribution from a sediment component that mixes with a depleted mantle source. The geochemical data when combined with the geological and petrographical observations suggest that the Nilüfer metabasic rocks represent ancient oceanic islands that were created by a heterogeneous mantle plume rising beneath the Palaeotethyan oceanic lithosphere. During the latest Triassic, these oceanic islands were incorporated into a subduction/accretion prism, where they mixed with the continental-derived assemblages of diverse origin, creating the Karakaya Complex. The intrusion of the SSZ-type metadiabases postdates the formation and deformation of the Complex.


Tectonomagmatic evolution of bimodal plutons in the central Anatolian crystalline complex, Turkey
Kadioglu, Yk; Dilek, Y; Güleç, Nilgün Türkan; Foland, Ka (University of Chicago Press, 2003-11-01)
The NW-trending Agacoren Intrusive Suite (AIS) on the east side of the Salt Lake (Tuz Golu), Turkey, is part of a curvilinear volcanoplutonic complex along the western edge of the central Anatolian crystalline complex (CACC). Granitoids constitute the predominant lithological group within the AIS and range in composition from monzonite through granite to alkali feldspar granite. Gabbroic rocks occur as irregular intrusive bodies with sinusoidal, irregular contacts with the granitoid plutons and vary from di...
The Upper Cretaceous intrusive rocks with extensive crustal contribution in Hacimahmutusagi Area (Aksaray/Turkey)
Köksal, Serhat (Central Library of the Slovak Academy of Sciences, 2019-06-01)
The Hacimahmutusagi area (Aksaray/Turkey) is located in the western part of the Central Anatolian Crystalline Complex (CACC). Gneiss and marble compose the basement units, while intrusive rocks are gabbros and granitoids. The pegmatitic hornblende gabbros contain pegmatitic to fine-grained hornblendes, plagioclase, clinopyroxene, and accessory opaque minerals. The fine-grained gabbros, on the other hand, are composed of plagioclase, hornblende, and biotite as major components whereas the apatite and opaque ...
Rapid cooling history of a Neotethyan ophiolite: Evidence for contemporaneous subduction initiation and metamorphic sole formation
PARLAK, OSMAN; Dunkl, Istvan; KARAOĞLAN, FATİH; Kusky, Timothy M.; Zhang, Chao; Wang, Lu; Koepke, Juergen; Billor, Zeki; Hames, Willis E.; ŞİMŞEK, EMRAH; Simsek, Gokce; ŞİMŞEK, TUĞÇE; Ozturk, Selena Ezgi (Geological Society of America, 2019-11-01)
The Beywhir-Hoyran Nappes, including Mesozoic carbonate platform rocks, deepsea sediments, and ophiolite-related units, crop out extensively on the western limb of the Isparta Angle in the Central Taurides, Turkey. The ophiolite-related rocks are represented by variably serpentinized harzburgitic mantle tectonites, tectonically underlain by a subophiolitic metamorphic sole and melange. The harzburgitic mantle tectonites and metamorphic sole are intruded by undeformed isolated dikes. Protoliths of the metamo...
Chronology of subduction and collision along the Izmir-Ankara suture in Western Anatolia: records from the Central Sakarya Basin
Ocakoğlu, Faruk; Hakyemez, Aynur; Açıkalın, Sanem; Altıner, Sevinç; Büyükmeriç, Yeşim; Licht, Alexis; Demircan, Huriye; Şafak, Ümit; Yıldız, Ayşegül; Yılmaz, İsmail Ömer; Wagreich, Michael; Campbell, Clay (Informa UK Limited, 2019-07-03)
Western Anatolia is a complex assemblage of terranes, including the Sakarya Terrane and the Tauride-Anatolide Platform that collided during the late Cretaceous and Palaeogene (80-25 Ma) after the closure of the Izmir-Ankara Ocean. Determining the precise timing at which this ocean closed is particularly important to test kinematic reconstructions and geodynamic models of the Mediterranean region, and the chronology of suturing and its mechanisms remain controversial. Here, we document the Cretaceous-Eocene ...
Bozkurt, Erdin (Geological Society of London, 1994-03-01)
In the southern sector of the Menderes Massif, north of Selimiye (Milas) augen gneisses interpreted as a deformed peraluminous granite have been dynamothermally metamorphosed and are surrounded by and intrude a regionally metamorphosed Palaeozoic 'envelope'. The granitic rocks exhibit a moderately-dipping mylonitic foliation and NNE-SSW- trending mineral elongation lineation. The progressive deformation of the granitic rocks produces a structural sequence typical of an extensional shear zone marked, from bo...
Citation Formats
K. Sayıt, “Geochemistry and petrogenesis of the oceanic island and subduction-related assemblages from the palaeotethyan Karakaya subduction/accretion complex, central and nw Turkey,” Ph.D. - Doctoral Program, Middle East Technical University, 2010.