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f Clastic-Carbonate Facies of Çaybağı Formation (Late Miocene-Early Pliocene), Eastern Elazığ, Eastern Turkey
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 18th International Petroleum and Natural Gas Congress and Exhibition of Turkey, May 2011, cp-377-00054
Abstract
The Çaybağı Formation located between Çaybağı and Kovancılar (eastern Elazığ) comprises fluvial and lacustrine deposits. Fluvial deposits are represented braided and low sinuosity river facies. The braided river deposits is characterized by parallel bedded conglomerate, planar cross-bedded conglomerate, planar-trough cross-bedded sandstone, low-angle cross bedded sandstone, parallel laminated sandstone and massive red mudstone. The low-sinuosity river deposits consist of parallel bedded conglomerate, planar-trough cross-bedded conglomerate, planar-trough cross-bedded sandstone, ripple-cross laminated sandstone, parallel laminated sandstone, sitstone, carbonaceous mudstone, massive red mudstone, gray claystone, clayey limestone and turba. The gray claystone and clayey limestone contain freshwater ostracods, gastropods and pelecypods. Lacustrine deposits compose of three main facies associations. These are delta, shallow lacustrine and open lacustrine. The delta deposits were grouped into subassociations; delta top, delta front and prodelta (open lacustrine). Facies in delta top subassociation are represented by parallel bedded conglomerate, planar-trough cross-bedded sandstone as channel deposits, parallel laminated sandstone, siltstone as levee deposits, red mudstone, gray claystone as flood plain deposits, clayey limestone as ponded water and carbonaceous mudstone and peat as swamp deposits. Two type of delta front subassociation were recognised; gilbert-type delta front subassociation and mouth-bar type delta front subassociation. Facies in the gilbert-type delta front subassociation are represented by parallel bedded conglomerate, parallel laminated sandstone as topset deposits, large-scale cross-bedded conglomerate up to 5 m thick as foreset deposit and low-angle cross bedded conglomerate, planar cross-bedded sandstone, parallel laminated sandstone as bottomset deposits. The mouth-bar type delta front deposits compose of parallel bedded conglomerate, planar-trough cross-bedded conglomerate, planar-trough parallel laminated sandstone and siltstone. The shallow lacustrine environment is represented by parallel laminated sandstone, siltstone, carbonaceous mudstone, gray claystone, clayey limestone, marl and turba. Fine-grained facies such as carbonaceous mudstone, gray claystone, clayey limestone, marl in this margin environment contain abundant ostracod, gastropod, pelecypod and charophytes fossils. The peats ovelie the carbonaceous mudstone and clayey limestone. There are rhizolits in the carbonaceous mudstone, clayey limestone near their upper contact with the peat. The clayey limestone contains abundant leaves and other plant fossils. The offshore lacustrine deposits consist of carbonaceous mudstone, gray claystone, clayey limestone and marl. These lithofacies contain poorly preserved fosil remains, freshwater ostracods and rare freshwater gastropod.