Acigöl rhyolite field, Central Anatolia (part 1): high-resolution dating of eruption episodes and zircon growth rates

238 U– 230 Th dating of chevkinite in high-silica rhyolites from La Primavera and Yellowstone calderas

“…Only the youngest chevkinite model age overlaps the 114 ± 2 ka eruption age derived by 40 Ar/ 39 Ar dating of sanidine (Christiansen et al, 2007). Dating of near eruption growth on the chevkinite crystals is likely to require ion microprobe sampling of unpolished rim surfaces of individual crystals in the same manner that has been used for other accessory minerals (e.g., Schmitt et al, 2011;Vazquez and Lidzbarski, 2012).…”

“…Pioneering studies using 238 U-230 Th disequilibrium to date crystallization of accessory minerals employed multi-grain analysis (e.g., Fukuoka and Kigoshi, 1974;Pyle et al, 1988) with unavoidable uncertainty about the age variation between and within single crystals. The advent of ion microprobe 238 U-230 Th geochronology greatly reduced this uncertainty by dating domains within single crystals, allowing unique insight into the timing of accessory mineral crystallization relative to eruption (e.g., Reid et al, 1997), intra-crystal age distribution (e.g., Storm et al, 2011), crystal growth rates (e.g., Schmitt et al, 2011) and the magnitudes of inheritance and antecrystic recycling (e.g., Bacon and Lowenstern, 2005). This paper describes ion microprobe 238 U-230 Th dating of chevkinite from Pleistocene rhyolites erupted from La Primavera and Yellowstone calderas (Fig.…”

Paleolithic occupations of the Göllü Dağ, Central Anatolia, Turkey

“…Cores showing different systems of preparation and exploitation tend to co-occur in the same localities, and based on the admittedly limited surface evidence, there is no evidence of separation or temporal sequencing in Levallois variants. At KD3, technologically similar Mousterian assemblage surface materials occur both immediately above and below a tephra from the Acıgö l volcano which erupted 190-200 ka (Schmitt et al 2011). However, we currently have no narrower time constraints on the Middle Paleolithic occupations of Gö llü Dag.…”

“…There is very limited chronological control over the Paleolithic sequence at KD3. A series of volcanic tephras within the Middle Paleolithic deposits come from an eruption of the Acıgö l volcano, which has recently been redated to roughly 190-200 ka (Schmitt et al 2011). The base of the archaeological sequence is formed by rhyolitic lava associated with the Kabak Tepe dome, dated to ca.…”

Göllüdağ Volkanik Kompleksi İçerisinde Kültürel ve Jeolojik Miras Öğeleri

“…Chataigner et al, 1998;Mouralis, 2003;Schmitt et al, 2011;Aydar et al, 2012) Bu çalışmanın odağını oluşturan Göllüdağ Volkanik Kompleksi dairesel bir alan içerisinde sistematik olarak gelişmiş riyolitik domlar ve ilişkili piroklastik yağış ve akıntı birimleri ile obsidiyenden oluşur. Bu birimlerden yapılan fizyon iz (FT) yöntemi (Bigazzi vd., 1993) ve K/Ar (Mouralis, 2003) tarihlendirmelerine göre 1.71-1.39 My arasına tarihlenen büyük bir kaldera patlamasını takiben gerçekleşen asidik dom yerleşimi başlamış ve 440 binyıl önce de sonra ermiştir (Şekil 3; Mouralis, 2003).…”