Petrogenesis of collision-related plutonics in Central Anatolia, Turkey
Yükleniyor...
Dosyalar
Tarih
2004
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Bv
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Central Anatolia exhibits good examples of calc-alkaline and alkaline magmatism of similar age in a collision-related tectonic setting (continent-island arc collision). In the Central Anatolia region, late Cretaceous post-collisional plutonic rocks intrude Palaeozoic-Mesozoic metamorphic rocks overthrust by Upper Cretaceous ophiolithic units to Make up the Central Anatolian Crystalline Complex. In the complex, three different intrusive rock types may be recognised based on their geochemical characteristics: (i) calc-alkaline (Behrekdag, Cefalikdag, and Celebi) (ii) subalkaline-transitional (Baranadag); and (ii) alkaline (Hamit). The calc-alkaline and subalkaline plutonic rocks are metaluminous I-type plutons ranging from monzodiorite to granite. The alkaline plutonic rocks are metaluminous to peralkaline plutons, predominantly A-type, ranging from nepheline monzosyenite to quartz syenite. All intrusive rocks show enrichment in LILE and LREE relative to HFSE, and have high Sr-87/(SR)-S-86 and low Nd-143/Nd-144 ratios. These characteristics indicate an enriched mantle Source region(s) carrying a subduction component inherited from pre-collision subduction events. The tectonic discrimination diagram of Rb vs. (Y+Nb) suggests that the calc-alkaline, subalkaline, and alkaline plutonic rocks have been affected by crustal assimilation combined with fractional crystallisation processes. The coexistence of calc-alkaline and alkaline magmatisin in the Central Anatolian Crystalline Complex may be attributed to mantle source heterogeneity before collision. The former carries a smaller intraplate component and pre-subduction enrichment compared to the latter. Either thermal perturbation of the metasomatised lithosphere by delamination of the thermal boundary layer (TBL), or removal of a subducted plate (slab breakoff) is the likely mechanism for the initiation of the post-collisional magmatism in the Complex. (C) 2003 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
postcollisional magmatism, granite, geochemistry, petrogenesis, Central Anatolia, Turkey
Kaynak
Lithos
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
72
Sayı
3-4
