Assessing the potential of a new widespread ignimbrite-forming eruption in Cappadocia, Central Anatolia

Abstract

The Cappadocian plateau is a tectonic horst within the Central Anatolian Volcanic Province (CAVP), characterised by multiple thick and widespread ignimbrites accumulated since the late Miocene (e.g. Aydar et al., 2012). These Cappadocian ignimbrites blanketed an extensive area of at least 40,000 km2  with an estimate volume of pyroclastic material exceeding 1000 km3 (Temel et al., 1998). The source of the oldest Neogene ignimbrites still remains a subject of intense debate, as the area is primarily covered by younger volcanic products. However, it is well-known that the two youngest ignimbrites were produced by the Acigöl caldera (Druitt et al., 1995). These are the Lower Acigöl Tuff  (LAT) and the Upper Acigöl Tuff (UAT), erupted at 190 ± 11 ka and 164 ± 4 ka respectively (Schmitt et al., 2011). Post-caldera explosive volcanism continued in Acigöl until more recent times, especially in the last 25ka with the eruption of several rhyolitic tephra cones, maars and related tephra rings (Uslular et al., 2022).Here, we propose that these monogenetic eruptions within the caldera basin may serve as precursory signals for larger caldera-forming events. Findings from a recent tephrostratigraphic investigation suggest that this series of volcanic eruptions has already occurred in Acigöl caldera as cascading events. This series includes the simultaneous emplacement of the Taskesik tephra ring and the UAT caldera-forming ignimbrite. Therefore, considering: 1) the high monogenetic volcanic activity in the last thousands of years within and outside the caldera, 2) the potential presence of eruptible magma beneath the caldera (Abgarmi et al., 2017), and 3) the increase in seismicity within the Central Anatolian Volcanic Province, the hypothetical scenario of a future caldera collapse eruption in Acigöl should not be dismissed.This study was founded by the PÜSKÜRÜM project, a Marie Curie Action (Grant No. 101024337) funded by the European Union’s Horizon 2020. Reference list:Abgarmi, B., et al. (2017). Structure of the crust and African slab beneath the central Anatolian plateau from receiver functions: New insights on isostatic compensation and slab dynamics: Geosphere, v. 13, no. 6, p. 1774–1787, doi:10.1130/GES01509.1.Aydar, E., et al (2012). Correlation of ignimbrites in the central Anatolian volcanic province using zircon and plagioclase ages and zircon compositions. J. Volcanol. Geoth. Res. 213, 83–97. doi:10.1016/j.jvolgeores.2011.11.005Druitt, T.H., et al. (1995). Late-Quaternary rhyolitic eruptions from the Acıgöl Complex, central Turkey. Journal of the Geological Society (London, United Kingdom) 152, 655–667. DOI: 10.1144/gsjgs.152.4.0655Schmitt, A. K., et al. (2011). Acigöl rhyolite field, Central Anatolia (part 1): High-resolution dating of eruption episodes and zircon growth rates. Contrib. Mineral. Pet. 162 (6), 1215–1231. doi:10.1007/s00410-011-0648-xUslular, G., et al. (2022). New findings on compositionally distinct maar volcanoes: A case study from Acıgöl (Nevşehir) caldera (Central Anatolia, Turkey)   . Front. Earth Sci.  DOI 10.3389/feart.2022.909951Temel, A., et al (1998). Ignimbrites of Cappadocia (Central Anatolia, Turkey): petrology and geochemistry. J. Volcanol. Geotherm. Res. 85, 447–471. doi:https://doi.org/10.1016/S0377-0273(98)00066-3