International Scientific and Vocational Studies Journal

The basement of the study territory covering the
Niksar-Erbaa territories and their immediate vicinity, located on the north and
above the North Anatolian Fault, forms the rocks belonging to Permo-Triassic
aged Karakaya Complex . The Mesozoic units forming the primary cover rocks in
the region consist of the Upper Jurassic-Lower Cretaceous aged Titonic facies
developed Calpionelli limestones, Upper Cretaceous aged tuffs and rugged rocks.
Mesozoic formations begin with Liassic sandstones, mudstones and limestones,
which come transgressively with angular unconformity over the basement rocks.
The Tertiary-Berriyan aged units with titanic facies bearing the ages of
Cenomanian-Maestrichtian aged units started with agglomerates and
reddish-colored, firmly adherent conglomerates. Upper Cretaceous units
continuing with carbonate-cemented polygenic sandstones, variegated colored
carbonate marl-mudstone plies and their partially metamorphosed derivatives and
recrystallized limestones are terminated by sandstone-marl-limestone
intercalations, including volcanic intercalations developed in
basaltic-andesitic dykes . In the pelagic mudstones belonging to the unit,  Pentacirinus
sp. and Belemnit fossils have been also identified in addition to such Ammonites sp., Phylloceras sp., Oxycerites
sp., Sphaeroceras sp., Ausseites sp.. It is unconformably
overlain by shallow marine units consisting of limestones and
limestone-sandstone alternations of Paleocene-Lower Eocene aged Nummulitic
limestones forming the second cover units of the area. In the neotectonic
period, sedimentary rocks of Pliocene aged are deposited in the sedimentary
areas formed by the formation and development of the North Anatolian Fault. The
youngest units of the region are the Pleistocene aged young basalt formations
and Quaternary aged alluvium, slope rubble and accumulation cones.