Geology and depositional environment of Nglanggeran Formation in Gunung Kidul Regency, Yogyakarta, Indonesia

Research is focused in the Gedangsari district of Gunung Kidul Regency, Yogyakarta, Indonesia. it lies between the latitudes of E7° 48°50 "S to E7° 51'30" and longitudes from N 110° 37’0” to N 110°39’44”. Geological mapping and sedimentary analysis have been done to the rock units in the study area by collecting measurements of the outcrops exposed. Lithology and sedimentary structures are the main aspects to differentiate and establish the nature of depositional environment. The Nglanggeran Formation is characterized by lava, basaltic and andesitic breccia to sandstone that accumulated during volcanism periods. The overall succession of Nglanggeran Formation suggests that the depositional environment was in shallow marine environment.

Key Word: Sedimentary analysis, depositional environment, Gedangsari, Gunung Kidul, Nglanggeran Formation.