Collision-related slab break-off volcanism in the Eastern Anatolia, Kepez volcanic complex (TURKEY)

Abstract

The Neogene-Quaternary volcanic products, related to Arabian and Anatolian Plate collision along the Bitlis Suture Zone, cover wide areas on both plates. One of these volcanic exposures on the Arabian Plate is the Kepez volcanic complex (KVC). This study aims explain to petrogenesis of KVC. Although some examples display alkaline affinities, the majority of the volcanic rock is calc-alkaline and can be defined in three main groups. 40 Ar/ 39 Ar data obtained from dacite, basalt and andesite rock groups within the KVC yield ages of between 13.5 and 15.5 Ma. Geochemical and petrographical data show that the andesitic rocks are products of homogeneous mixing between basic end-member magmas and dacitic magmas which are the products of partial melting of lower crustal compositions. Basaltic products of KVC are asthenospheric mantle derived, while dacitic and andesitic volcanic rocks are crustal origin. High Sr and Nd isotope ratios may indicate that andesitic and dacitic rocks originated from continental crust. The lithospheric mantle, which is subducting underneath the Anatolian plate, must have experienced slab break-off processes 13-15 million years ago and sunk into the asthenosphere. KVC were produced with the collision between Arabian and Anatolian Plates and related uplift of the East Anatolia region.

Geochemical Characteristics of Anatolian Basalts: Comment on “Neogene Uplift and Magmatism of Anatolia: Insights From Drainage Analysis and Basaltic Geochemistry” by McNab Et Al.

“…However, the older rocks with the orogenic geochemical signature have been recently attributed to assimilation and fractional crystallization processes acting on the asthenosphere‐derived mantle (Kocaarslan & Ersoy, ). Through the eastern part of the region (Figure ), there are other volcanic fields (namely Yamadağ and Kepez volcanic complexes) including early to late Miocene volcanics (~19–10 Ma; Ekici, ; Ekici et al, ; Kürüm et al, ) with mainly orogenic geochemical affinity (Kürüm et al, ). In fact, the petrological evolution and the source characteristics have still been discussed in the literature, and the region has been generally considered with the NE‐SW trending corridor of the East Anatolian Volcanic Province (EAVP; i.e., W‐EAVP; Kürüm et al, ).…”

“…For instance, the volcanism in the Galatia volcanic province has been considered to initiate in late Cretaceous (~76 Ma; Koçyiğit et al, , and references therein) as an early phase of Galatia arc evolution. In addition, there are also other volcanics around the central Anatolia with ages between 20 and 14 Ma, namely, Yamadağ and Kepez volcanic complexes in the E‐CAVP (19–10 Ma; Ekici, ; Ekici et al, ; Kürüm et al, ) and Erenlerdağ‐Alacadağ and Sulutaş Volcanic Provinces in the SW‐CAVP (22–16 Ma; Gençoğlu‐Korkmaz et al, ; Temel et al, ). Therefore, if the volcanism in central Anatolia was divided into different phases, the volcanism in the eastern and southwestern parts of the CAVP should also have been taken into consideration.…”

Pliyo-Kuvaterner Yaşlı Göbekören Volkaniklerinin Petrolojisi (Kangal-Sivas)

“…Göbekören Volkanikleri'nin bazı değişim diyagramlarındaki konumları. a) La/Lu-La; b) Zr-La (Wilson, M., 1989;Alpaslan ve Temel., 2000;Ekici, 2016). (Wilson, M., 1989;Alpaslan ve Temel., 2000;Ekici, 2016).…”

“…Variation of selected some trace elements diagrams of Göbekören Volcanics. a) La/Lu-La; b) Zr-La (Wilson, M., 1989;Alpaslan ve Temel., 2000;Ekici, 2016).…”

“…Figure 10. Variation of selected some trace elements diagrams of Göbekören Volcanics a) Y/Nb-Zr/Nb (Wilson, M., 1989;Alpaslan ve Temel., 2000;Ekici, T., 2016), b) La/Sm-La/Ta (Alparslan ve Temel., 2000;Said et.al., 2012). Şekil 11.…”