Structure of the Galatean Volcanic Province,Turkey

The Galatean volcanic province (GVP), located in northwestern Anatolia, is an ENE-WSW-oriented belt. The province as a whole corresponds to a depression filled with volcanic and sedimentary rocks. The northern margin of the GVP is truncated by the North Anatolian fault, whereas it is surrounded by a continental sedimentary pile interfingering with volcanics on the south. Field and aerial photographic studies reveal that the GVP consists of several volcanic complexes scattered throughout the province. Nine of these complexes are recognized, each covering an area of hundreds of km² of circular or ellipsoidal form, with moderately to well-preserved morphology. They include calderas, stratovolcanoes characterized by central vent (s), and radial flows of both lava and volcaniclastics. Several continental basins are disposed between the major volcanic complexes. These basins are isolated from one another or are partly connected and may differ in age and lithology. Available radiometric and paleontologic age determinations suggest that almost all volcanic complexes as well as the sedimentary basins started to develop during early to middle Miocene and continued to late Miocene time. The faults detected in the southern part of the province are Pliocene and older, and reflect normal faulting.