Formation of the Kula volcanics and geophysical data signatures

Kula is located on a block of crystalline rocks of the Menderes Massif, which is delimited by a southward-tilted footwall block of the Simav Graben or a southward-tilted hanging-wall block of the Alaşehir graben. The Kula volcanic area (Burnt Country ?Katakekaumene?) is on the main İzmir-Ankara road, which has a number of interesting volcanological aspects. The youngest volcanics of western Anatolia, with widespread plateau basalts and well-preserved craters and lava flows, are excellent examples of an alkali basalt province in an area of active rifting. These older grabens (SW-NE trending Gördes, Demirci and Selendi) have thinner sedimentary fills (less than 1 km).With respect to the extensive volcanism and high heat flow values, the Kula volcanic region and the Yellowstone area in USA show great similarities. The Yellowstone area volcanic field is one of the Earth?s most voluminous accumulations of rhyolitic and basaltic material was ejected in three eruptive events, starting about 2 Ma, each of which vented hundreds to thousands cubic kilometers of pyroclastic deposits. The diminutive size of the Kula cinder cones is probably a result of a very low flow rate of magma to the surface and this small volume reflects the small amount of extension in the region (ß < 1.2 where ß = final length of crust: initial length of crust).Plateau basalts do not have magnetic signatures. Magnetic anomalies are very distinctive and these are easily correlated with the second and third phase basaltic intrusions (first and second phases of volcanic cones) of the region having the magnitudes up to 3000 nT. The cones of the volcanoes are at the intersections of the SW-NE trending faults separating the grabens of Demirci and Selendi. The depths and widths of these bodies are in the ranges of 100-200 m and about 1000 m, respectively. These intrusions are almost vertical or slightly inclined northwards.According to our aeromagnetic results, there are two main magmatic bodies at depth, although at least five volcanic cones have been observed at the surface. In addition to that, these two magmatic bodies are located south of their volcanic products indicating that there should be an available tectonic setting which cause to reaching of the mantle materials to the surface.