TY - JOUR TI - KEBERADAAN JENIS LEMPUNG PADA FORMASI SAMBIPITU, STUDI KASUS JALUR KALI NGALANG, KABUPATEN GUNUNGKIDUL, DAERAH ISTIMEWA YOGYAKARTA THE PRESENCE OF CLAY TYPE IN SAMBIPITU FORMATION, CASE STUDY AT KALI NGALANG TRAVERSE, GUNUNGKIDUL RESIDENCY, SPECIAL PROVINCE OF YOGYAKARTA PB - Lembaga Penelitian Universitas Gadjah Mada Yogyakarta AV - public A1 - Setyo Pambudi l), NIDN 052426101 A1 - Sukandarrumidi 2), NIP A1 - Sugeng Wiyono 3), NIDN N2 - ABSTRACT The research area is part of map sheet 48/XLII-k, belonging to Gedangsari District, Gunungkidul Regency, the Special Province of Yogyakarta. The research area is devided in two geomorphological units, i.e. strong undulated denudational hill unit and weak undulated denudational hill unit. These geomorphological units have been controlled by lithological resistancy, erosion, and mass movement. This area is devided in four lithological units, i.e. Nglanggran Andesite Breccia, Sambipitu Tuffaceous Sandstone, Sambipitu Calcareous Sandstone and Oyo Limestone. Depositional process was happened at Early Miocene, until Middle Miocene, dominated by submarine fan turbidity current. At first, it was volcanic clastic deposition, followed by sediment clastic deposition and the latest was calcareous clastic deposition. When deposition of volcanic clastic and sediment clastic were happened volcanic activity which was indicated by lava flows was occured. Tectonic activity was happened after deposition of Oyo Limestone, possibly at Middle Pliestocene, in which has been indicated by Kali Ngalang fault. The type of clay mineral in Sambipitu Formation is monmorillonite (Ca-bentonite) which was formed by degradation transformation and neoformation process. The Capacity of Cation Exchange (CEC) in sample ST -09 is 36.45 meq Na20/100 gram montmorillonite and ST-25 is 13.64 meq Na20/100 gram montmorillonite. The Bleaching Power in sample ST-09 is 0.4375 % K2Cr207/100 gram montmorillonite and in sample ST-25 is 0.4687 % 1<2Cr207/100 gram montmorillonite. Based on the value of CEC, Bleaching Power, X-Ray Defraction and Major Oxide analysis, montmorillonite which has been found in Sambipitu Formation can be used for purifier palm oil which was compared to Bimoli Oil Standart in cleanness aspect. The experiment was done in the Laboratory Scale. Keywords: Volcanic clastic, montmorillonite and bleaching power JF - Mediagama ID - ITNYREPOID1032 EP - 52 UR - https://repository.itny.ac.id/id/eprint/1032/ SP - 41 SN - 0215-093X Y1 - 2001/01/02/ KW - Volcanic clastic KW - montmorillonite and bleaching power Volcanic clastic KW - montmorillonite and bleaching power VL - III IS - 1 ER -