High-K volcanism in the Afyon region, western Turkey: from Si-oversaturated to Si-undersaturated volcanism

Abstract

Volcanic rocks of the Afyon province (eastern part of western Anatolia) make up a multistage potassic and ultrapotassic alkaline series dated from 14 to 12 Ma. The early-stage Si-oversaturated volcanic rocks around the Afyon city and further southward are trachyandesitic volcanic activity (14.23 ± 0.09 Ma). Late-stage Si-undersaturated volcanism in the southernmost part of the Afyon volcanic province took place in three episodes inferred from their stratigraphic relationships and ages. Meliliteleucitites (11.50 ± 0.03 Ma), spotted trachyandesites, tephryphonolites and lamproites (11.91 ± 0.13 Ma) formed in the first episode; trachyandesites in the second episode and finally phonotephrites, phonolite, basaltic trachyandesites and nosean-bearing trachyandesites during the last episode. The parameter Q [normative q-(ne ? lc ? kls ? ol)] of western Anatolia volcanism clearly decreased southward with time becoming zero in the time interval 10-15 Ma.

Alluvial-lacustrine sedimentation and volcaniclastic deposition in an intracontinental tectonic graben: paleoenvironmental evolution of the Neogene Sinanpaşa Basin,west-central Turkey

“…The onset of sedimentation in the Sinanpaşa Basin, with alluvial lacustrine deposits and a first pulse of volcanic activity, was similar as in the other adjacent grabens, such as the Bigadiç-Balıkesir Basin (Helvacı, 1995), Uşak-Güre Basin (Karaoğlu and Helvacı, 2012), Emet-Kütahya Basin (Helvacı, 1977;Baş, 1986;Helvacı et al, 2017), Kırka-Eskişehir Basin (Helvacı and Orti, 2004), Afyon Basin (Aydar, 1998;Akal et al, 2013;Prelevic et al, 2015), and Şuhut-Sandıklı Basin (Koçyiğit and Deveci, 2007b;Gündoğan et al, 2012). Similar to neighboring grabens, the Sinanpaşa Graben basin has been filled by fluvial alluvial fan deposits (first sedimentary products) since the Early Miocene.…”

“…Similar to neighboring grabens, the Sinanpaşa Graben basin has been filled by fluvial alluvial fan deposits (first sedimentary products) since the Early Miocene. The emplacement of volcanic products in the present case is attributed to the Afyon stratovolcano and related vents, which continued to be active in the Middle to Late Miocene (Aydar and Bayhan, 1995;Aydar, 1998;Akal, 2003;Akal et al, 2013). Researchers widely agree that extensional graben seismotectonics continued to be active in the region until the Middle Pliocene (Bingöl, 1977;Gündoğdu, 1984;Yalçın et al, 1985;Floyd et al, 1998;Helvacı and Orti, 1998;Helvacı and Alonso, 2000;Koçyiğit et al, 2000;Koçyiğit and Özacar, 2003;Deveci, 2005, 2007b).…”

“…The available isotopic dates of the lavas and pyroclastic deposits of Afyon volcanism indicate that the volcanic processes were active in the Middle to Late Miocene (14.75 ± 0.3 Ma to 8.0 ± 0.6 Ma according to Besang et al, 1977; 14.23 ± 0.09 Ma according to Akal et al, 2013). This notion was supported by Becker-Platen et al (1977) on the basis of vertebrate remains and plant spores in the contemporaneous sedimentary deposits.…”

“…Şengör et al, 1985;Gürsoy et al, 2003;Çoban and Flower, 2007;Koçyiğit and Deveci, 2007b) and location of the present study area near Afyon (black frame). The ages of main volcanic fields (shaded and numbered) are: (1) Galatean volcanics, 20.8-17 Ma and 10.6-9.5 Ma (Keller et al, 1992;Wilson et al, 1997;Tankut et al, 1998); (2) Cappadocia volcanics, 9.12 ± 0.09 to 2.52 ± 0.49 Ma (Aydar et al, 2012); (3) Kırka volcanics, 21.0-18.8 Ma (Besang et al, 1977;Yalçın, 1988;Helvacı and Alonso, 2000); (4) Afyon volcanics, 14.75 ± 0.3 to 8.0 ± 0.6 Ma (Becker-Platen et al, 1977;Besang et al, 1977;Akal et al, 2013;Prelevic et al, 2015); (5) Isparta volcanics, 4.07-4.60 Ma (Lefevre et al, 1983;Platevoet et al, 2014) and 1.50 ± 0.18 to 1.38 ± 0.13 Ma (Nemec et al, 1998); and (6) Bigadiç volcanics, 23.5-17.8 Ma (Gündoğdu et al, 1989;Helvacı, 1995;Erkul et al, 2005). The neotectonic volcanic grabens in West Anatolia contain economically important borate and other evaporite deposits.…”

“…From west to east, the main borate deposits of Turkey are in the areas of Bigadiç-Sultançayırı (Balıkesir), Kestelek (Bursa), Emet (Kütahya), and Kırka (Eskişehir) (Figure 1). Therefore, the West Anatolian Neogene Basinscombining lacustrine sedimentation and volcanic activity -have long been studied, including their stratigraphy and tectonic structure (Okay, 1984;Göncüoğlu et al, 1992Göncüoğlu et al, , 1996Okay and Tüysüz, 1999;Koçyiğit et al, 2000;Koçyiğit and Özacar, 2003;Gürsoy et al, 2003;Candan et al, 2005;Koçyiğit and Deveci, 2007b) as well as volcanism (Keller and Villari, 1972;Becker-Platen et al, 1977;Besang et al, 1977;Aydar, 1998;Francalanci et al, 2000;Aydar et al, 2003;Akal, 2008;Prelevic et al, 2012;Akal et al, 2013). However, little modern sedimentological research has thus far been conducted.…”