The Study of Diagenetic Processes in the Chehel Kaman Formation in the Eastern of Kopet-Dagh Region,North-East of Iran

The chehel kaman formation of the upper paleocene age,a carbonate and siliciclastic strata,which is located in the kapeh-dagh basin. two sections where considered for the purpose of research into the effective diagenetic processes of this formation. the first section,cheshmeh qorban,270.8m thick,located 140km of mashhad - sarakhs highway,while the second section,shourlaq section,288.3 m thick,is situated 130km of mashhad - mozduran - sarakhs highway. for petrography study,among 120 samples 100 thin sections prepared. as the result of petrography,cementation,micritization,neomorphism,dissolution,and compaction,are the main diagenetic effects. these processes have taken place at the four marine diagenetic stages of the underground and surface fresh water. to indentifying porosity,gypsum wedge has been used. all changes including type and percentage were plotted for each section. the results of the investigations,indicates that the min porosity in the cheshmeh qorban section is 3%,max porosity is 7%. in other hand,in the shourlaq section,the min porosity is 2%,and max porosity is 6%. in the cheshmeh qorban section,fracturing,and in the shourlogh section vuggy is the main type of porosity.