The Oligocene–Miocene Asmari Formation of the Zagros Basin is a thick sequence of shallow water carbonate. Asmari formation is the youngest and most important reservoir rock of the zagros Basin in the south-west of Iran.
The Asmari formation has been divided into two members: one is the Sandstone Member of Ahwaz in the south-west of the Khuzestan area and the other one is the Evaporate Member of Kalhor in the Lorestan Province. This formation is divided into three units: the lower Asmari with an Oligocene age, the Middle Asmari with an Aquitanian age, and Upper Asmari with a Burdigalian age. However, these divisions do not exist everywhere.
Also, in some parts of Iran, the lower boundary of Asmari formation is in contact with the Pabdeh Shale formation which is of Paleocene-Oligocene age, but in central Lorestan this formation is overlying the Late Eocene Shahbazan formation and in internal Fars it show a paraconformable contact with the Jahrum formation (Eocene).
The Asmari formation is covered by anhydrites of the Gachsaran formation which is of Early Miocene age, and in internal Fars the upper boundary of Asmari formation is in contact with the Early Miocene Razak formation.
The photo shows the Asmari limestone formation (As) and Gachsaran formation (Gs) Along the shore of Karun 4 Lake Dam near Lordegan city in Chahar mahal va bakhtiyari Province.
Keywords: Asmari formation , Bakhtiyari formation , Gachsaran formation , Geotourism , Iran , Iran Geology , Iran Geotourism , Pabdeh formation , Zagros Mountain , zamingasht