The oldest rocks in the Penbegˇli-Tut inlier of
southeastern Turkey belong to the Meryemuşagˇi Formation
(base not seen); they are mostly clastic rocks of ?late Precambrian
age, overlain with angular unconformity by unfossiliferous quartzites
(270 m est.) of the Zabuk Formation. The latter unit is succeeded
conformably by the Koruk Formation (Lower?/Middle Cambrian),
comprising almost 200 m of dolomite and grey and red nodular
limestone, and the Sosink Formation (Middle Cambrian), about 600 m of
silty mudstone and sandstone with a few thin limestone beds, overlain
unconformably by Cretaceous carbonates. The closest comparison is
with the Derik-Mardin area, 220 km to the east, where the section is
more complete. The upper Koruk Formation contains trilobites of the
Pardailhania and Solenopleuropsis biozones;
trilobites from the Sosink Formation indicate the
Solenopleuropsis Biozone, a post-Solenopleuropsis
interval, and a level with Holasaphus mesopotamicus, known
only from the Derik area. Acritarchs from the highest Koruk Formation
and the whole of the Sosink belong to the lower part of microflora
A2, described from the Middle Cambrian of eastern
Newfoundland.