Petrological And Geochemical Features Of Biga Peninsula Granitoids, Nw Anatolia, Turkey

Autor: AYDIN, Ümit, ŞEN, Pınar, ÖZMEN, Öner, ŞEN, Erdal
Přispěvatelé: Jeoloji Mühendisliği
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Bulletin of the Mineral Research and Exploration, Vol 160, Iss 160, Pp 81-115 (2019)
Volume: 160, Issue: 160 81-115
Bulletin of the Mineral Research and Exploration
ISSN: 0026-4563
Popis: In Northwest Anatolia, widespread magmatism developed due to collision between Anatolide-Tauride platform and Sakarya continent during Late Cretaceous-Early Tertiary period. The granitoids in Biga Peninsula are products of post-collisional magmatism following the convergence of the northern branch of Neotethyan Ocean and developed in two different stages as Eocene and Oligo-Miocene. Eocene Karabiga, Güreci, Kuşçayır and Dikmen granitoids are granite and diorite-granodiorite; Oligo-Miocene Sarıoluk, Yenice, Kestanbol, Eybek, Evciler, Çamyayla and Alanköy granitoids are diorite, granodiorite, monzonite and Q-monzonite in composition. Metaluminous and peraluminous granitoids have similar geochemical variations and exhibit post-collisional geochemical signatures. Trace element patterns are almost similar to those observed in upper crust and GLOSS (Global Subducting Sediment) patterns with depletion in high field strength (HFS) elements (Nb, Ta, Ti, Zr, Hf). But, Oligo-Miocene Sarıoluk, Yenice-Çakıroba, Kestanbol, Evciler, Çamyayla, Alanköy and Eocene Karabiga, Güreci and Kuşçayır granitoids have higher Th and U contents relative to upper crust and GLOSS. Dikmen, Yenice-Hamdibey, Yenice-Eskiyayla and Eybek granitoids have lower Th content. Geochemical variations indicate that partial melting and fractional crystallisation- crustal contamination processes are effective in their genesis and evolution. Trace element ratios also indicate subduction signatures in their genesis and Rb/Ba, Rb/Sr ratios suggest mantle melting rather than crustal melting. Accordingly, post-collisional Biga Peninsula granitoids were derived from a previously metasomatised lithospheric mantle source, which was enriched during northward subduction and closure of the northern branch of Neo-Tethys Ocean beneath the Sakarya continent, since variations in Rb, Cs, Th, La and Sm reveal that lithospheric mantle was mesomatised by both aqueous fluids and sediment melts.
In Northwest Anatolia,widespread magmatism developed due to collision between Anatolide-Taurideplatform and Sakarya continent during Late Cretaceous-Early Tertiary period. Thegranitoids in Biga Peninsula are products of post-collisional magmatismfollowing the convergence of the northern branch of Neotethyan Ocean anddeveloped in two different stages as Eocene and Oligo-Miocene. Eocene Karabiga,Güreci, Kuşçayır and Dikmen granitoids are granite and diorite-granodiorite;Oligo-Miocene Sarıoluk, Yenice, Kestanbol, Eybek, Evciler, Çamyayla and Alanköygranitoids are diorite, granodiorite, monzonite and Q-monzonite in composition.Metaluminous and peraluminous granitoids have similar geochemical variationsand exhibit post-collisional geochemical signatures. Trace element patterns arealmost similar to those observed in upper crust and GLOSS (Global SubductingSediment) patterns with depletion in high field strength (HFS) elements (Nb, Ta,Ti, Zr, Hf). But, Oligo-MioceneSarıoluk, Yenice-Çakıroba, Kestanbol, Evciler, Çamyayla, Alanköy and EoceneKarabiga, Güreci and Kuşçayır granitoids have higher Th and U contents relativeto upper crust and GLOSS. Dikmen, Yenice-Hamdibey, Yenice-Eskiyayla and Eybekgranitoids have lower Th content. Geochemical variations indicate that partial meltingand fractional crystallisation- crustal contamination processes are effectivein their genesis and evolution. Trace element ratios also indicate subductionsignatures in their genesis and Rb/Ba, Rb/Sr ratios suggest mantle meltingrather than crustal melting. Accordingly, post-collisional Biga Peninsulagranitoids were derived from a previously metasomatised lithospheric mantle source,which was enriched during northward subduction and closure of the northern branchof Neo-Tethys Ocean beneath the Sakarya continent, since variations in Rb, Cs,Th, La and Sm reveal that lithospheric mantle was mesomatised by both aqueousfluids and sediment melts.
Databáze: OpenAIRE
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