Geology and geomorphology of the Cappadocia volcanic Province, Turkey
Throughout historical time, the region of Cappadocia has occupied a geographic position that has made this land an essential member of the geologic, environmental, as well as human network enlivening the Eastern Mediterranean basin. As a result, the definition of the "Cappadocia" as a region depends on the type, characteristics and origin of landscapes one has in mind, as well as on the time interval concerned. The word "Katpatuka" seems to go back to a Hittite toponym, transformed into "Cappadocia" at a time as far back as the sixth century BC. According to Herodotus, this "Cappadocia" extended from the Taurus Mountains in the south to the Black Sea north of the Pontus region, and was bound to the west by Lycaonia (i.e. the west central part of Anatolia, where today's city of Konya is located) and to the northwest by Galatia (today the regions of Bolu, Ankara, Corum and Yozgat) On the other hand, touristic information leaflets and books praising "Cappadocia" refer to a small region confined between the cities of Nevsehir, Nigde and Kayseri (formerly the Hattian Mazaca, then Eusebia at the Argaeus and, finally Caesarea) the Roman Capital City of Cappadocia. This area, which attracts millions of visitors per year, possesses a high density of peculiar landscapes combining specific natural landforms (badlands, canyons and fairy chimneys, e.g. Sarikaya et al. 2015a) and humansculpted troglodytic landforms (caves, dwellings, churches and settlements) recording a long history of occupation since antiquity (Ozbasaran 2011; Ozbasaran et al. 2018; Mouralis et al. 2019a; Ciner and Aydar 2019) These historical and touristic territorial dimensions of "Cappadocia" superimpose another dimension drawn by a unique geological and geomorphological territory whose evolution is deeply rooted in the last 15 million years. This geological region, wider than the touristic one and smaller than the historical one, presents specific geological structures and geomorphological landscapes dominated by volcanic and tectonic processes that commenced during the middle Miocene, c. 15 million years ago (Dewey and Sengor 1979; Sengor and Yilmaz 1981; Aydar et al. 2012) In this context, an energetic magmatic activity produced groups of geological and geomorphological features, creating a high variety of volcanic destruction and accumulation forms, intermingled with active tectonics controlling a maze of small to wide basins dispersed in the region (e.g. Dhont et al. 1998; Kocyigit and Beyhan 1998; Sarikaya et al. 2015b) River and slope (deep and superficial) erosion responding to geologic (rock resistance vs uplift vs volcanic dams) as well as climatic (hydrology vs precipitation) forcing superimposed varied shapes onto the volcanic substrate. The boundaries of this "Cappadocia" thus draw a large region of roughly square shape limited (1) to the north, by the Kizilirmak (the classical Halys) River valley where Avanos city is located; (2) to the west by the Tuz Lake (Salt Lake) basin, on the eastern side of which the town of Aksaray is located; (3) to the south, the W E alignment of Hasandag, Keciboyduran and Melendiz volcanoes, at the eastern end of which the city of Nigde is located; (4) to the east, to the rectilinear cliffs of the Cappadocian plateau reaching the Sultansazligi Plain and the Erciyes Volcano at the foot of which the city of Kayseri was founded. Within these boundaries, the present issue contains several articles concerning two important aspects of the evolution of the geological, geomorphological and biological features that took and still take part in forming and constructing today's Cappadocia. The articles of this special issue concern two broad topics: (1) palaeoenvironments (see papers by Dogan et al. 2019; Gurbuz et al. 2019; Tuncer et al. 2019) and (2) processes and consequences of magmatic activity and their relationships with the evolution of the volcanic landscapes through time and space (see papers Catherine Kuzucuoglu catherine.kuzucuoglu@lgp.cnrs.fr
Mediterranean Geoscience Reviews