Ibrahim Turkmen¹

(1) Firat Universitesi, Muhendislik Fakultesi, Jeoloji Bolumu, Elazig, Turkey

ABSTRACT: Fluviolacustrine-Palustrine Deposits of The Pliocene Çaybagi Formation, Eastern Turkey

The Çaybagi Formation occurs in the Eastern Turkey. The north of the formation is surrounded by Upper Cretaceous magmatic Complex and Eocene Deposits while its south is by only Upper Cretaceous magmatic Complex.

The formation is composed of three main facies association; a-Fluvial deposits, b- Palustrine deposits, c- Lacustrine deposits. Fluvial deposits is represented mainly by fining-upward interbedded sequences. Conglomerate and trough-planar cross-stratified sandstone occur in the lower part of fining-upward sequences and siltstone-mudstone in the upper part. The sequence is interpreted as meandering river deposits. Palustrine deposits are characterized by siltstone, brown-gray mudstone, claystone and peat, interbedded with both fluvial deposits and lacustrine deposits. Claystones are massive, gray to green in color and commonly contain macrophytic debris. Peat facies are passing vertically both claystone and brown-gray mudstone. Lacustrine deposits are found at the westerly of the basin, characteristic lithologies are stratified limestone, brecciated limestone and massive marl. The stratified limestones consisting bioturbation traces are usually micritic mudstone-wackestone with gastropod and ostracod that form beds ranging 20-40 cm in thickness. These limestones are interbedded with brecciated limestones. The brecciated limestones are succeeded by intraclastic limestones. The massive marls are generally grey to white in color, contain ostracod, gastropod and plant material (common leaf remain), and alternate with stratified limestones.

Fluvial deposits have lateral and vertical transition to the lacustrine - palustrine deposits toward western of the basin.

The Pliocene fluviolacustrine - palustrine deposits are present in the western part of the Neogene fold and thrust belt of the Eastern Turkey located in the east-west narrow extensional intermountain basin.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado