New nomenclature of Mt. Penanggungan stratigraphy, Pasuruan and Mojokerto Regency, East Java

Abstract

Mt. Penanggungan is geographically located in UTM X : 675400 to 685800, and UTM Y : 91621200 to 9153900, within the jurisdiction of Mojokerto and Pasuruan regency, East Java province. For long period, Mt. Penanggungan has been described as “Penanggungan Volcanics”, in form of Upper Quarter - Pyroclastic Unit of Penanggungan. The research involved four steps: (1) Preparation step, (2) Data collection step, (3) Data analysis step, (4) Reporting step. Based on field data and adjusted with Van Zuidam (1983) modification, authors divided the morphology into 6 units: Upper volcanic slope (V1), Middle volcanic slope (V2), Lower volcanic slope (V3), Parasiter Cone (V4), Volcanic Cone (V5), and Volcanic Valley (V6). Research showed that Mt. Penanggungan has varied lithology, such as pyroclastic flow sedimentaiton, pyroclastic avalanche sedimentation, lahar and lava sedimentation. Every unit showed certain characters. Mt. Penanggungan and its parasiter cone could be categorised into Khuluk of Mt. Penanggungan, which were: Mt. Geting sand dune, Mt. Gajahmungkur sand dune, Mt. Bekel sand dune, Mt. Jambe sand dune, Mt. Kemuncup sand dune, Mt. Wangi sand dune, and Mt. Bendo sand dune. Mt. Penanggungan kept historical stories such as temples, shrine cave, altar of ritual, andpetirtaan. These sites were mainly located on lava of Mt. Penanggungan and other lava of its parasiter cone. There were at least 120 remaining sites of Ancient Mataram (10th century) until Majapahit era (14th century).