Reconstruction of the sedimentary environment of the Tarbur Formation based on microfacies and microtaphofacies analysis in the Murak area (southwest of Semirom)

Reconstruction of the sedimentary environment of the Middle-Upper Maastrichtian deposits (Tarbur Formation) in the Murak area (southwest of Semirom) was performed based on Microfacies and microtaphofacies analysis. The formation with 239 m thickness consists of limestone and shale. Meanwhile, the Tarbur deposits overlie the Gurpi Formation and is covered by the Paleocene deposits. Seven and five microfacies and microtaphofacies were recognized based on the main components and sedimentological and taphonomical features, respectively. In addition, these microfacies and microtaphofacies were deposited in homonicnal carbonate ramp. From the viewpoint of vertical distribution and interpretation of microfacies and microtaphofacies, the Tarbur deposits were formed in the energetic environment (under the influence of the storm waves) in the study area. Therefore, communities of rudist are absent and the green algae (Dasycladales) are abundant in the study area. Concerning the high rate of detrital grain input and increasing of nutrients, the bryozoans were performed the encrusting more than other organisms.