Akademik Veri Yönetim Sistemi
Turkish Journal of Earth Sciences, cilt.11, sa.2, ss.127-160, 2002 (SCI-Expanded)
In central Turkey the Cankiri Basin developed between the Kirşehir and Sakarya continents as a collisional basin during the Tertiary. Along the southern border, between Yozgat and Yerköy, the basin fill predominantly comprises continental and shallow marine facies, and overlies the Late Cretaceous Kirşehir Block unconformably. The Yoncali formation (shallow marine sandstones, shales and limestone lenses), the Incik formation (terrestrial conglomerates and sandstones) and the Bayat formation (subaerial lavas and pyroclastic rocks) are Middle to Late Eocene in age and grade laterally and vertically into each other. These units are unconformably overlain by a Middle Miocene continental sequence that is composed of terrestrial conglomerates, laminated shales and evaporites, called the "cover series". These dominantly continental sequences are generally devoid of fossils. Coal and carbonaceus shale horizons of the Çankiri Basin fill and the "cover series" were sampled and their spore and pollen associations were examined to define the palynomorph content, and determine ages and palaeoclimatic and palaeocological conditions of the Tertiary units in the Çankiri Basin. The palynologic determinations indicate that the Yoncali and Incik formations are of Middle-Late Eocene age and the overlying cover units of the Kizilirmak and Bozkir formations are of Middle Miocene age. In addition to sedimentologic features, the palynomorph association, observed in the Yoncali formation, indicates that the unit was deposited in swamps between the channels of a deltaic environment. The presence, in particular, of the tropical Gleicheniaceae. Schizeaceae, Icacinaceae, Palmae and the tropical-subtropical Cyrillaceae, Simaroubaceae, Anacardiaceae, and Sapotaceae indicate a moist tropical climate during deposition of the coals and shales of the Yoncali formation. Cupressaceae, Taxodium, Oleaceae, Nyssa, Carya, Engelhardtia, Cyrillaceae, Alnus, Ulmus and Pterocarya, observed in the Kizilirmak and Bozkir formations, indicate that the units were deposited in a lacustrine environment under subtropical climatic conditions.