Simultaneous with establishment of GSI, was set up, sector named regional geology in 1338 to prepare geological maps,after that its name was changed to stratigraphy group.This group has had a close and integrated correlation with different groups of GSI such as petrology, paleontology ,exploration and engineering geology since the start of establishment and its result is many reports and articles that have been published in interior and foreign .Preparing geological maps of Middle East is within the framework of preparing world geological maps.The work result of stratigraphy group experts is geological maps with different scales that any of them has scientific ,economic and constructive usage.
In field geological surveys, geologists consider geological phenomena and present these phenomena in from of signs onto maps. One of the most important phenomena that is considered in geological maps is minerals that information involved to it is given to exploration group. Moreover, geologists introduce tectonically and engineering geological phenomena such as fractures ,placations ,landslides and faults of active and non-active whether from the scientific viewpoint or from the viewpoint of basic data for precise operation and performance of constructive –national projects .
The experts of stratigraphy group research on ancient sedimentary basins by field surveys and study of rock samples and find out type and process of their appearance .The experts try to find out pale climatology in different times by study of facieses and sediments bulk .These studies can be a noticeable help in recognition of hydro carbonic tank origins or kinds of coal reservoirs.