Diabase dykes from Bogazkale (Corum), Central Anatolia: Geochemical insights into the geodynamical evolution of the northern branch of Neotethys

Balc, Ugur
Sayıt, Kaan
In the Bogazkale region (Corum, Central Anatolia), pieces of Neotethyan oceanic lithosphere are found in an ophiolitic melange. Within the melange, there are occurrences of isolated diabase dykes that intrude serpentinized and carbonatized ultramafics. The diabases are phaneritic, holocrystalline and equigranular, and consist of plagioclase and hornblende as the main primary mineral phases. They have all undergone low-grade alteration, to varying extents, as reflected by the presence of secondary minerals, including chlorite, epidote, prehnite and actinolite. Immobile trace element systematics suggest that all diabases are of subalkaline basalt composition and display negative Nb anomalies in the N-MORB-normalized plots. They also display flat to slightly LREEdepleted patterns in chondrite-normalized diagrams. The relative Th (and La) enrichment coupled with NMORB-like HFSE composition of the diabases suggests their derivation from a depleted mantle source metasomatized by slab-derived fluids/melts. Overall trace element characteristics are consistent with an oceanic backarc origin. 40Ar-39Ar radiometric dating on the hornblende grains extracted from the two diabase dykes yield ages of 176.30 +/- 0.52 Ma and 178.82 +/- 0.80 Ma (Toarcian, Early Jurassic). This suggests the existence of an intra-oceanic subduction zone within the Izmir-Ankara-Erzincan (IAE) Ocean during the Early Jurassic, which can also be traced along the western (Vardar Zone) and the eastern (Sevan/Akera ophiolites) extensions of the Northern Neotethys. This result requires the presence of a Northern Neotethyan oceanic crust of pre-Early Jurassic age, which in turn may suggest that oceanization of the IAE Ocean have occurred during the Late Triassic or earlier.


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The Suphan stratovolcano is one of the major Quaternary eruption centers of post-collisional volcanism in eastern Anatolia, located in the zone of convergence between the Arabian and the Anatolian plates. We document the geological and geochemical evolution of Suphan in terms of volcanostratigraphy, geochronology (Ar-40-Ar-39), isotope composition (Sr, Nd, Pb) and bulk-rock geochemistry. Our new Ar-40-Ar-39 data, along with previously published K/Ar ages, indicate an age of 0 center dot 76-0 center dot 06 M...
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The volcanic province of North-West Turkey contains a number of intra-continental alkaline volcanic eruption sequences formed along the localized extensional basins developed in relation with the Late Cenozoic extensional processes. The volcanic suite comprises the extracted melt products of adiabatic decompression melting of the mantle that are represented by small-volume intra-continental plate volcanic rocks of alkaline olivine basalts and basanites with compositions representative of mantle-derived, pri...
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Hf-Pb-Os isotope compositions and highly siderophile element (HSE) abundance variations are used to evaluate the mantle source characteristics and possible effects of differentiation processes in lavas from western Turkey, where the eruption of Late Miocene to Quaternary OIB-type intraplate mafic alkaline lavas followed pre-Middle Miocene convergent margin-type volcanism. Concentrations of Os, Ir, and Ru (IPGE) in the OIB-type intraplate lavas decrease with fractionation for primitive melts (MgO > 10 wt%), ...
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Citation Formats
U. Balc and K. Sayıt, “Diabase dykes from Bogazkale (Corum), Central Anatolia: Geochemical insights into the geodynamical evolution of the northern branch of Neotethys,” GEOCHEMISTRY, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35407.