Evolution of Can-Etili (Canakkale-NW Turkey) lignite basin: Sedimentology, petrology, palynology and lignite characterization

This study examines the development and sedimentology of Can-Etili lignite basin in Biga Peninsula (NW Turkey) along with the palynologic and petrographic properties of the coals in this region. The Can-Etili lignite basin discordantly overlies Oligocene-aged Can volcanics. The basin consists of caldera type sedimentation developed by the combined effects of volcanism and tectonics. The volcanic rocks forming the basement of the basin consist of andesitic, dacitic and basaltic lava flows as well as agglomerates, tuff and silicified tuffs, and kaolin which is their alteration product. The basement volcanic rocks cooled from high potassium and calc-alkaline magma. The trace element geochemistry of different rocks within the volcanics reveals that they are from a volcanic arc. The Can Formation contains lignites and consists of 6 lithofacies representing alluvial, fluvial, marsh and lacustrine environments. These lithofacies are the lower volcanogenic conglomerate, the claystone, the lignite, the laminated organic claystone, the tuff intercalated sandstone-siltstone and the upper volcanogenic conglomerate. The lignite in the basin is limnic and is formed in a non-fluvial marsh and marsh-lake environment. An abundant percentage of vegetation (Engelhardia, Sapotaceae, Cyrillaceae) is compatible with temperate and subtropical climatic conditions in the basin during sedimentation of lignite. The coals of Can-Etili basin are humic with high sulfur content (6-6.5% average) mostly containing huminite compounds belonging to the class of lignite-low bituminous (C-A) coal. Their coalification rank is between 0.38% and 0.56% Ro. The coals are formed in limnic-limnotelmatic marsh zones based on their microlithotype components. The inorganic components of the coal mostly consist of pyrite and clay. The trace elements, As, Th, U and V, are higher than international coal standards. The coal quality is adversely affected by high sulfur content and sulfur driven trace element enrichments. The lignite reserve (possible-proved) of Can-Etili basin is greater than a hundred million tons, and the average coal seam thickness is 17 m. The lignite production in the basin is 3 mt/year and 1.8 million tons of this are used in the local thermal power plant. (C) 2015 International Research and Training Centre on Erosion and Sedimentation/the World Association for Sedimentation and Erosion Research. Published by Elsevier B.V. All rights reserved.