DESCRIPTION OF THE FOSSILIFEROUS UNITS AT PASALAR, TURKEY

The Miocene sedimentary strata at Paşalar are described in relation to their probable source. They accumulated at the southern edge of an internal drainage basin, which is formed in basement rock consisting of Palaeozoic/Mesozoic metamorphic rocks extensively replaced by intrusive igneous rocks. The metamorphic rocks are presently exposed in a narrow band along a very restricted part of the basin within 2-3 km of the fossil site, forming the lower slopes of an extensive range of hills. The hills are mainly composed of the intrusive granitic rocks, and differences in the composition of the Miocene sediments reflect differences in the source materials from which they were derived. The Miocene sediments are divided into upper and lower series. The lower series includes five sedimentary units which are all highly calcareous the unfossiliferous lower calcareous silt at the base of the sequence; the greenish grey sand, a poorly sorted massive deposit of sands and gravels accumulated over a short period of time and richly fossiliferous; the upper sand, poorly fossiliferous; and the upper calcareous silt, similar to the lower but with some fossils. The source material for these four units consists entirely of the metamorphic rocks on which they are resting. Onlapping the lower series are channel-fill sands and gravels, which have an uncertain relationship with the upper series of non-calcareous braided river deposits. The upper series sediments are derived mainly from the intrusive granitic rocks, and they contain almost no fossils. These differences in source and method of emplacement distinguish the upper series from the fossiliferous series. Many of these units have been modified post-depositionally by soil formation. © 1990.