Quality and petrographic characteristics of the lacustrine Ermenek coal (early Miocene), Turkey

The early Miocene Yenimahalle Formation including alluvial-lacustrine sedim ents and a mineable coal seam with an average of 5 m in thickness rests unc onformably upon the basement and is also unconformably overlain by marine l imestones of the middle-late Miocene Mut Formation in the Ermenek coal basi n. The coal basin in the present study has been subdivided into two areas, Canakci and Pamuklu-Tepebasi, which are separated by the basement and a fau lt, in order to determine coal properties in detail. The investigated subbi tuminous coals with an average of 0.40%Ro huminite reflectance often contai n gastropod shells (Planorbidae) which commonly maintain the original arago nite and calcite composition. The coals have similar chemical properties an d petrographic composition in the two areas, but their sulphur contents are clearly different. In the Canakci area the coals on an air-dried basis con tain distinctly less total sulphur (avg. 1.3%) and organic sulphur contents (0.13-0.15%) than in the Pamuklu-Tepebasi area (avg. 4.5% and 4.25%, respe ctively). This difference is interpreted to be controlled by mire chemistry and sedimentation during peat formation.