Comparison of stratigraphic rock and sedimentary environment of Shemshak formation in Central Alborz: sections Glendrood - Lavij – Vaz, Iran

The study area lockated in the central Allborz whch is in accordance with U shape Caspian Sea. In this Research Shemshak Formtion in the Glandrud region has been Studid and compared in three Section A, B, C in therm Litology Effective Tectonice prossesing in the Formation,Sedementary Environment and Squence of Calasses. These Sections are consisting of sedementry Layer of shemshak Formation, the layer bandray (Elika Formtion & older Formtion) and upper bandray(Lar-Dalichai) in the type section desegnation of shemshak ۴ litozone the litilogy of this intity is much more diverse. Sedementry rocks in the studied area are based on desert traps including sandeston types such as quartzit conglomerent, laterite, sub liticarenait, shaillean thin layers and Coal which are Generally Paraconformity or angular unconformity with dolomitic – calcrus cross. on the due to the earlier Cimmerian orogeny phse, carbonate sedimentary environment changed to coal depasetis formation.the UPPER Triassic carbonat rocks in the study area are somtime contain oroganic matte and iron oxide hidroxid of shemshak which formed in the sedementry Environment tidal flats or lagoon. In addition the lateritic section at the base of shemshak formation shows the sedementry discontinuity of the earlier cimmirian land tenure phase.In the section A at the base of shemshak formation is on the part of  Laterit Hoeizon but at the upper part bordered Dalichai formation. At th section of B on the in the hillside of Sordar the Lower boundray of Shemshak Formation contain Laterit Hoeizon the form of Paraconformity and is located on Elika Formation but the upper boundary in the form of angular unconformity bordered Dalichai formation. At th section of C lower boundary of shemshak formation does not contain bauxite- laterit and is located on the Elika formation and the upper bandray ends in direction of Dalichai Formation. in term sedimentary environment Dolomit–Limeston formed in the Tidal Flats, Sandeston in the shallow coastal or condition open River and Coal has been depasited castal marsh and sowamp. The bauxite – Laterit horizon are of peneplain type.

Keywords:

Forland , Stratigraphy , Shemshak , Quartzarenit , Lagoon