Browsing by Author "Unal, Esin"

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Late Acheulean Lithic Assemblages From Locality 010 at Gurgurbaba Hill (Eastern Anatolia)
(Cambridge Univ Press, 2022) Baykara, Ismail; Sarikaya, M. Akif; Sahin, Serkan; Dincer, Berkay; Unal, Esin
The province of Van in north-eastern Turkey served as a land bridge between Africa and Eurasia during the Palaeolithic. The region is of particular relevance for understanding the movement of hominins between these continents. This study concerns the lithic remains from a locality at Gurgurbaba Hill, named Locality 010, north of the village of Ulupamir (Ercis district). Locality 010 was dated to 311 +/- 32 kya by terrestrial cosmogenic nuclides method, which coincides with Marine Isotope Stage 9 (MIS 9), a Middle Pleistocene interglacial period. The assemblage from this site is attributed to the Late Acheulean and resembles that of the southern Caucasus. This similarity indicates that the artefacts from Locality 010 were probably produced by late Lower Palaeolithic technology in a broad sense. These findings suggest local adaptations of late Middle Pleistocene hominins to high plateau environments.
Petrology and Geochemistry of the Quaternary Mafic Volcanism To the Ne of Lake Van, Eastern Anatolian Collision Zone, Turkey
(Oxford Univ Press, 2017) Oyan, Vural; Keskin, Mehmet; Lebedev, Vladimir A.; Chugaev, Andrey V.; Sharkov, Evgenii V.; Unal, Esin
Collision-related Quaternary mafic volcanism to the north of Lake Van (Eastern Anatolia, Turkey) occurred by eruptions from both volcanic centres and extensional fissures trending approximately north-south. We report new major, trace and rare earth element abundances, Sr-Nd-Pb isotope ratios and K-Ar ages for basaltic and more evolved hawaiitic and mugearitic lava flows. The new K-Ar ages indicate that magmatic activity occurred between 1.0 and 0.4 Ma. The volcanic products consist of mildly alkaline lavas, ranging in composition from basalt to hawaiite and mugearite. Energy-constrained assimilation and fractional crystallization (EC-AFC) model calculations suggest that the least evolved basaltic samples were unaffected by the combined effects of fractional crystallization and crustal contamination processes, in contrast to the more evolved hawaiitic and mugearitic lavas, which have experienced up to 2-3% crustal assimilation. Calculations based on crustal temperatures and Curie point depths indicate that the magma chamber, from which the basic to evolved lavas were derived, might be located at a depth of around 6-8 km, within the upper crust. Enrichment of large ion lithophile elements and light rare earth elements relative to high strength field elements, and higher Sr-87/Sr-86 and Pb isotopic ratios and lower Nd-144/Nd-143 of the least evolved basaltic samples indicate that the mantle source region of the Quaternary mafic magmas might have been enriched by melts that were derived from subducted sediments with a partial melting degree of around 10% rather than from Altered Oceanic Crust melts and fluids. Our model melting calculations show that the basaltic melts might have been produced by melting of a mantle source containing both amphibole and garnet with a partial melting degree of similar to 3%. Results of our petrological models indicate that a metasomatized mantle source, which was infiltrated by a mixture of 93% mantle melt and 7% sediment melt plus 0.01% residual rutile, added to mantle melt, could have been the source composition of the basaltic melts that produced the Quaternary mafic volcanism.