The Geological Evolution of Sorgun (Yozgat)-Yildizeli̇ (Si̇vas) Foreland Basin, Petrographic, Geochemical Aspects and Geochronology of Volcanism Affecting the Basin

Abstract

Sorgun-Yıldızeli basin is an east-west trending asymmetric marginal foreland (peripheral foreland basin) formed as a result of the consumption of oceanic crust of the northern branch of Neotethys due to the collision of Sakarya continent in the north and Kırşehir Block in the south. It provides much information about the geodynamic evolution of the region. The basement of the study area consists of Late Palaeozoic-Mesozoic Akdağmadeni Massif. Akdağmadeni Massif was intruded by CenomanianMaastrichtian granitoids and is overlain tectonically by Late Cretaceous Artova ophiolitic melange within the İzmir-Ankara-Erzincan suture zone and by Cenomanian-Maastrichtian Darmik Formation. The uppermost section of the sequence which consists of generally clastic and coarse clastics is named the Konacı member. When the sedimentation and volcanism continued in the basin, gabbroic intrusions occurred as sills and laccoliths cutting the Boğazköy Formation. These gabbroic rocks were named the Yaycılar Gabbro. The age of 51.0 ± 0.7 Ma was found for the Yaycılar Gabbro with the 40 Ar/ 39 Ar geochronologic method. As a result of slab breakoff, the relicts of the consumed oceanic crust and the released massif were uplifted rapidly and the units of Middle-Late Eocene Tokuş Formation were deposited transgressively on the Boğazköy Formation and on outcropping basement rocks in the basin which was controlled by an extensional tectonic regime. Upper Miocene-Pliocene (İncesu Formation), Pliocene and Quaternary terrestrial sediments were deposited unconformably on all older units.

İzmi̇r-Ankara-Erzi̇ncan Sutur Zonundaki̇ (Si̇vas Kuzeydoğusu) Eosen Yaşli Karataş Volkani̇tleri̇ni̇n Jeoki̇myasal Özelli̇kleri̇

“…7). Akçay and Beyazpirinç (2017) and Göçmengil et al (2018) also indicated that fractional crystallization processes were effective in the development of Eocene volcanics, crop out in Almus, Yıldızeli, Kiremitli and Pazarcık area, at the west of the study area.…”

“…The plots of these values on the SiO 2 versus K 2 O/P 2 O 5 diagram show that the effects of crustal contaminations increase from basaltic trachyandesites towards trachyte (Figure 10b). Akçay and Beyazpirinç (2017), indicated that subduction zone enrichment and/or crustal contribution had important part in magmas generated Pazarcık and Kiremitli volcanics, and these more significant in Kiremitli volcanics. Göçmengil et al (2018) indicated that Almus volcanics had negligible amounts of crustal contamination comparing with Yıldızeli volcanics.…”

“…We have tried to compare and discuss the geochemical characteristics of Karataş volcanics with the results of the earlier works carried out on the Eocene volcanics by Akçay and Beyazpirinç (2017) and Göçmengil et al (2018) in the west of the study area, between Yozgat and Sivas provinces. 6).…”

“…(Figure 1). These volcanics have been studied by a number of researchers (Yılmaz and Tüysüz, 1984;Büyükönal, 1985;Tüysüz and Dellaloğlu,1992;Yılmaz et al, 1994Yılmaz et al, , 1997Alpaslan and Terzioğlu, 1998;Alpaslan, 2000;Koçbulut et al, 2001;Keskin et al, 2008;Akçay et al, 2008;Dalkılıç et al, 2008;Atakay Gündoğdu, 2009;Görür vd., 2010;Tiryaki and Ekici, 2012;Akçay and Beyazpirinç, 2017;Göçmengil et al, 2018). And, various models have been proposed for the origin of these volcanics which outcrops from west of Sivas to Çankırı and Çorum; development in the compressional regime (Bozkurt and Koçyiğit, 1995;Tüysüz et al, 1995;Görür and Tüysüz, 1997;Kaymakçı et al, 2003;Okay and Satır, 2006), slab break off oceanic lithosphere in the North plunging subduction environment (Keskin et al, 2008), development in the post-collisional regime (Genç and Yılmaz, 1997;Keskin et al, 2004;Altunkaynak and Dilek, 2006;Altunkaynak, 2007), crustal thickening (Topuz, 2005), crustal delamination and lithospheric subduction (Temizel et al, 2016;Yücel et al, 2017;Göçmengil et al, 2018).…”

Derbent-Eymi̇r Bölgesi̇nde (Yozgat, Türki̇ye) Artova Ofi̇yoli̇ti̇k Karmaşiğindaki̇ Manganez Yataklarindan Mi̇neraloji̇k Bulgular

“…The upper Cretaceous and Lutetian units in the study area are the products of submarine volcanism (Özcan et al, 1980). The Neogene units consisting of sand, clay and lacustrine sediments are the youngest deposits in the region (Ketin, 1966;Akçay and Beyazpirinç, 2017; Figure 1). The ophiolitic series and lower Eocene rocks underwent several deformation events and therefore, metamorphics and crystalline basement rocks, serpentines and radiolarite-bearing ophiolitic series and lower Eocene layers were intensely fractured and folded.…”