تعيين مينرالوژي اوليه ، بازسازي محيط رسوبي نهشته هاي سازند روته حوضه البرز مركزي با استفاده از مطالعات پتروگرافي و ژيوشيميايي

Primary Mineralogy, reconstruction of sedimentary environment of the Ruteh Formation in Central Alborz. A Petrography & Geochemical approach

Ruteh Formation is overlain with distinct laterite - detrital horizon between Elika and Ruteh Formation and is underlain disconfonnably by Dorud Formation. The Permian sequence is composed of 160 meters of dark to light fossiliferous limestone. Geochemical studies illustrates that these carbonates were affected mostly by distal pheratic meteoric diagenesis. Elemental and518O and 513C values of limestone in Ruteh Formation led to recognition of calcitic mineralogy. These data fall within subpolar Permian Limestone (Tasmania , Australia ) field due to similar calcitic mineralohgy. Paleotemperature study indicates an ambient temperature between 27-34.5°c . Fades analysis and petrographic studies led to recognition of 9 microfacies deposited in an open marine,bar and lagoon environments . On the basis of facies chemistry, the high Sr contens are due to aragonitic components deposited in lagoon to back barrier environments. The high Mg concentration is related to the high abundance of red algae (Gymnocodiacea ).