Masoomeh Sohrabi Mollayousefi - Department of Petroleum, Mining and Materials Engineering, Islamic Azad University, Central Tehran Branch

In this research lithostratioghrphy and biostratigraphy have been studied in south Polour; in central Alborzzone. According to the field observations and obtains, about ۸۰ meter of the thickness of Delichay formationin this zone is systematically sampled. In the whole mass of rocks, lithological characters have been noticedwhile sampling. Ammonite criteria samples have gathered among the layers and debris, sent to the laboratoryin order to study and identify the type and specie. The importance is that the lithography characteristicsconsisting texture and structure, while studying doesn’t differ a lot with the type section of Delichai .In thissection, Delichay formation has been observed alternately made of Marly lime with rich Ammonite Fauna. Thelower layer of Delichay formation is Shemshak and its upper layer also reaches the Lar limy formationgradually. The whole view of the formation is gray. According to the paleontological studies, in the wholeformation thickness, ۸ types of Ammonite have been identified. It should be mention that in regard todestruction degree of visible signs in Ammonite samples, recognizing the specie is possible which preventsrecognizing the type. The oldest Ammonite which is identified in the study section is Procerites (Earlyathonian) and the youngest is Reineckeia sp. (Late Cllovian). According to investigations the age of Delichayformation is determined Early Bathtonin to Late Callovian.

Ammonite, Bathonian, Callovian, Damavand, Alborz