A stratigraphical correlation and the deposit environmental changes of the Ruteh formation in Alborz

In order to study the stratigraphical correlation and environmental changes of the Ruteh Formation deposits in the Alborz Region, four stratigraphical sections in the central Alborz Region (South of Nowshahr, Chalus, and Amol) and Eastern Alborz (Ghoznavi) were studied. Lithology of the Ruteh Formation in the Alborz Region are almost limestone rock and the deposits of the Formation are specified by detrital facies and carbonated facies (limestone and dolomite). The deposits have a great thickness and their thickness is variable in different sections. Therefore the Ruteh Formation thickness in Manjir section (South of Nowshahr) is 493m, and 200m in the North – West Harijan section, 480m in Amol section and the thickness reaches 115m in Ghoznavi (Eastern Alborz) section. Ruteh Formation in these sections was determined at Artinskian- Murghabian age based on the fossils extracted. Based on the field study, and thin sections, four facies including Tidal flat, Lagoon, Braaier and Open marine were identified.