Investigation of paleosol in Shurijeh Formation; Example from the Ghorghoreh section in the eastern Kopet- Dagh sedimentary basin
The Shurijeh Formation (Upper Jurassic-Early Cretaceous) is composed of siliciclastic facies in the eastern KopetDagh basin. Moreover, the identified paleosol in this formation is calcisol type. The identified calcisols of the Ghorghoreh section have particular micro and macro morphology shapes. Since the beta microfabric is dominant in these paleosol, therefore microorganisms activity plays an important role in the formation of calcretes. The paleosols in this section have been affected by processes such as boring, micritization, cementation, and pyritization. The CO2 paleopressure has been calculated to be about 2237.1 to 2981.08, which is about 7.99 to 10.65 times more than todaychr('39')s values and seems to be similar to the modeled values for that period. In addition to biogenic activities, the water table fluctuations in the phreatic zone led to the formation of calcretic paleosols in the studied section.