TY  - JOUR
A1  - Akal, Cuneyt
A1  - Koralay, O. Ersin
A1  - Candan, Osman
A1  - Oberhänsli, Roland
A1  - Chen, Fukun
T1  - Geodynamic significance of the early triassic karaburun granitoid (Western Turkey) for the opening history of Neo-Tethys
JF  - Turkish journal of earth sciences = Türk yerbilimleri dergisi
N2  - The Karaburun Peninsula, which is considered part of the Anatolide-Tauride Block of Turkey, contains clastic and carbonate sequences deposited on the northern margin of Gondwana. The Palaeozoic clastic sequence, which is intruded by the Early Triassic granitoid and tectonically overlies a Mesozoic melange sequence, can be divided into three subunits: a lower clastic subunit consisting of a sandstone-shale alternation, an upper clastic subunit consisting of black chert-bearing shales, sandstone and conglomerate, and a Permo-Carboniferous carbonate subunit. The lower Triassic Karaburun I-type granitoid has a high initial Sr-87/Sr-86 ratio (0.709021-0.709168), and low Nd-143/Nd-144 ratio (0.512004-0.512023) and epsilon Nd (-5.34 to -5.70) isotopic values. Geochronological data indicate a crystallization (intrusion) age of 247.1 +/- 2.0 Ma (Scythian). Geochemically, the acidic magmatism reflects a subduction-related continental-arc basin tectonic setting, which can be linked to the opening of the northern branch of Neo-Tethys as a continental back-arc rifting basin on the northern margin of Gondwana. This can be related to the closure through southward subduction of the Palaeotethys Ocean beneath Gondwana.
KW  - Karaburun
KW  - Neo-Tethys
KW  - Palaeo-Tethys
KW  - diorite
KW  - Triassic
KW  - magmatism
Y1  - 2011
U6  - https://doi.org/10.3906/yer-1008-1
SN  - 1300-0985
VL  - 20
IS  - 3
SP  - 255
EP  - 271
PB  - Tübitak
CY  - Ankara
ER  - 
TY  - JOUR
A1  - Hajialioghli, Robab
A1  - Moazzen, Mohssen
A1  - Jahangiri, Ahmad
A1  - Oberhänsli, Roland
A1  - Mocek, Beate
A1  - Altenberger, Uwe
T1  - Petrogenesis and tectonic evolution of metaluminous sub-alkaline granitoids from the Takab Complex, NW Iran
JF  - Geological magazine
N2  - The Takab complex is composed of a variety of metamorphic rocks including amphibolites, metapelites, mafic granulites, migmatites and meta-ultramafics, which are intruded by the granitoid. The granitoid magmatic activity occurred in relation to the subduction of the Neo-Tethys oceanic crust beneath the Iranian crust during Tertiary times. The granitoids are mainly granodiorite, quartz monzodiorite, monzonite and quartz diorite. Chemically, the magmatic rocks are characterized by ASI < 1.04, AI < 0.87 and high contents of CaO (up to similar to 14.5 wt %), which are consistent with the I-type magmatic series. Low FeO(t)/(FeO(t)+MgO) values (< 0.75) as well as low Nb, Y and K(2)O contents of the investigated rocks resemble the calc-alkaline series. Low SiO(2), K(2)O/Na(2)O and Al(2)O(3) accompanied by high CaO and FeO contents indicate melting of metabasites as an appropriate source for the intrusions. Negative Ti and Nb anomalies verify a metaluminous crustal origin for the protoliths of the investigated igneous rocks. These are comparable with compositions of the associated mafic migmatites, in the Takab metamorphic complex, which originated from the partial melting of amphibolites. Therefore, crustal melting and a collision-related origin for the Takab calc-alkaline intrusions are proposed here on the basis of mineralogy and geochemical characteristics. The P-T evolution during magmatic crystallization and subsolidus cooling stages is determined by the study of mineral chemistry of the granodiorite and the quartz diorite. Magmatic crystallization pressure and temperature for the quartz-diorite and the granodiorite are estimated to be P similar to 7.8 +/- 2.5 kbar, T similar to 760 +/- 75 degrees C and P similar to 5 +/- 1 kbar, T similar to 700 degrees C, respectively. Subsolidus conditions are consistent with temperatures of similar to 620 degrees C and similar to 600 degrees C, and pressures of similar to 5 kbar and similar to 3.5 kbar for the quartz-diorite and the granodiorite, respectively.
KW  - granitoids
KW  - partial melting
KW  - Neo-Tethys
KW  - Takab
KW  - NW Iran
Y1  - 2011
U6  - https://doi.org/10.1017/S0016756810000683
SN  - 0016-7568
VL  - 148
IS  - 2
SP  - 250
EP  - 268
PB  - Cambridge Univ. Press
CY  - New York
ER  -