Öz
The surveyed area is situated about 30 km, north of Adana and to the east of the Seyhan River the highest elevations being 375-400 m. There are Tertiary and Quaternary formations in this area. The Tertiary has been distinguished as the Miocene and Pliocene deposits.
The Miocene begins with marlsj grey in color, which correspond to Foley's «Upper Shales». These grey marls are dense, locally conchoidal, sometimes foliated, sometimes with small joints, and sometimes with thin sandstone layers; they are of the Upper Helvetian or Tortonian age. Their thickness is 1500 m. (together with those lying outside of our area).
These marls are overlain conformably by cross-bedded somewhat concretionary sandstones, bearing abundant micro-fossils, and partly corresponding to Foley's «Upper Sandstone» beds. The pink and red sandstones of the upper layers of these sandstones resemble very much the transition beds in the other parts of the Adana region. The total thickness of the cross-bedded and concretionary sandstone formation is 1500-1700 m. The age of the series is Tortonian and even, partly, Upper Tortonian.
The yellow-colored, marly sandstone and blue marl series overlies this formation with a slight unconformity. The average thickness of this series is 1130 m. However, thicknesses ranging between 750 m. and 1700 m. have been also observed. This formation abounds in micro-fossils as well as in macro-fossils, and according to these fossils its age is Sarmatian-Pontian.
Over this Miocene series lie —with an angular unconformity— lacustrine limestones or conglomerates and sandstones of the Pliocene age.
In our area there are also Quaternary terrace deposits, caliches, old and new alluvium. Two minor volcanic activities took place here: one during the Tortonian and the second at the end of it.
The Helvetian and Tortonian seas being in constant movement and were favorable for abundant organisms. The depth of these seas varied from time to time. Originally they were locally brackish, later on they turned to be fresh-water and continental.
The following formations have been deposited (chronologically) in the Miocene seas: 1. grey marls, 2. cross-bedded, somewhat concretionary sandstones, 3. yellow-colored, marly sandstones and blue marls.
From the study of the deposits in the Miocene sea, we gather that the sea was in oscillation and had undercurrents.
The Helvetian-Tortonian strata were folded together (Styrian phase). Thereafter the Alpine orogeny folded also the Sarmatian-Pontian strata (Rhodanian phase). The Pliocene strata were also folded (Valaque folding phase). During this folding period the following anticlines were formed:
1. The Tülüler anticline, 2. The Evreşim Uşağı-Turunçlu anticline, 3. The Mustafalı anticline, 4. The Kızılkaş-Karga Kekeç anticline.
These anticlines are 2.5x3,5 km. or 1.5x10 km. in amplitude. Their dip is 3° to 8° and sometimes 10°-20°, and their strike is NE-SW, WWN-EES or E-W. The folding pressure came from NNW.
The anticlines appear to have formed a unilateral free virgation. There are no large faults in the area; only a few faults ranging from 1 to 1.5 km. at most, are encountered and their displacements or heaves are not important.
The cross-bedded, partially concretionary strata may be oil reservoirs and the marly parts may be bedrocks. There are some anticlines in this formation or in the Sarmatian-Pontian marls which may be cap-rocks.
In conclusion it may be said that the oil seepages have been observed in the Helvetian marl intercalated sandstone formation, located at Topallı, north of the surveyed area, and that there are some oil possibilities in this area.