Stratigraphy & Sedimentology  Sedimentary rocks make up only about 5 percent of the Earth’s crust. However, because they form on the Earth’s surface, they are widely spread in a thin veneer over underlying igneous and metamorphic rocks. As a result, sedimentary rocks cover about 75 percent of continents. Many sedimentary rocks have high. economic value. Oil and gas form in certain sedimentary rock..                           

    This  science deal with  study of the processes of the accumulation and deposition of sediments and physical properties of its particles or grains. The processes     which the  natural sediments, both lithified and unlithifiede were formed  , and how to record and measure these features.                                                            

   The subject of this course is Sedimentology a word that literally means "the study of the Sediment and mechanism of sedimentation". To understand the sedimentology its not easy task because our planet is not an unchanging mass of rocks, but rather a dynamic body possessing a long a complex history. The science of sedimentology is traditionally divided into two branch areas sedimentation and sedimentary rocks ,first semester of our study is sedimentation ,the second semester is petrography of sedimentary rocks.