Boğaz is geologically distinguished above all by Boğazköy obsidian. This volcanic glass occurs in black and red and lies at the edge of the Acıgöl Caldera. Its age is estimated at approximately 160,000 to 180,000 years. To get your bearings, it is worth looking separately at its formation, extent and rock fabric: these describe different scales of the same geological feature.

How the obsidian formed

Lava emerged from fissures around the Acıgöl Caldera and cooled rapidly, forming Boğazköy obsidian. It belongs to the second eruptive phase of the rhyolitic Acıgöl Complex. A massive lava flow spread out in a fan shape and in stages as far as the present-day plain of Boğazköy. The obsidian originated in the area around Kocadağ. This clearly links the caldera surroundings as the geological setting where it formed with the Boğazköy plain as the extent of the lava flow.

Narrow zones run along fissures in Boğazköy obsidian. The technical term for this form is a dike: obsidian extending as a narrow zone along a fissure. The term refers to the shape of the occurrence, while black and red describe its colour. The Boğazköy obsidian dikes are listed as volcanic geomorphosites in the Kapadokya Geopark. If you are considering visiting in person, check accessibility in advance.

Age and rock fabric

Boğazköy obsidian at the edge of the Acıgöl Caldera is assigned an age range of 0.15 to 0.175 million years. It is therefore older than the obsidian in the caldera domes, which is 0.075 to 0.15 million years old. This comparison relates the marginal location to the caldera domes and supplements the approximate age estimate for Boğazköy obsidian.

In hand specimens, attention is drawn to the spherulites: they are 1 to 5 cm in size, occur singly, in composites or in clusters, and are surrounded by volcanic glass. Hand specimens of Boğazköy obsidian also display spherulitic and amygdaloidal textures. Thus, the geological features range from individual spherulites of a clearly specified size to two named textural types in hand specimens.

Other perspectives in Nevşehir

Nevşehir offers a different focus from Boğaz: the Karanlık Kilise is dated to the late 11th or early 12th century. It received very little light through a small window in the narthex, which helped preserve the particularly vivid colours of its frescoes. The frescoes depict scenes from the life of Jesus as well as images of saints. Here, the focus is on dating, lighting conditions and subject matter, while Boğaz is associated with the geology of obsidian.

Another cultural highlight in Nevşehir is the Damat-İbrahim-Paşa Complex, built in 1726–1727 by Nevşehirli Damat İbrahim Paşa. The ensemble includes a mosque, a madrasa, a caravanserai, a primary school, an imaret, a bathhouse and two fountains. While the Karanlık Kilise is explored through its frescoes and dating, the complex brings together several different architectural forms. This gives Nevşehir a distinct architectural perspective alongside Boğaz’s geological theme.

Discover more destinations: Kozaklı, Ayvali, Bozca Köyü, Ürgüp, Mazı, Gülşehir, Kaymaklı, Avanos

For the broader travel overview: Nevşehir.