Geology of Kuwawur, Sukolilo District, Pati Regency, Central Java Province Sheet 49/XXXIX - n (85-n)

Abstract

Maliki, J.,(2009), Geology of Kuwawur, Sukolilo District, Pati Regency, Central Java Province, Geological Mapping Report (unpublised), Geological Engineering Program, Faculty of Engineering, Diponegoro University. Geological mapping aims to determine the condition of local geological mapping. Mapping area is located in Kuwawur area, district Sukolilo, Pati regency, Central Java Province. From the observation in the field, then the mapping area is divided into 4 units of geomorphology units namely the cone karst of steep hills, undulating hills unit cone karst and alluvial plains karst units. Drainage pattern that developed in the region are parallel and mapping multibasinal. Stratigraphy of the mapping of rock units with 5 units of the rock sequence from the oldest to the youngest of batupasir units, units batupasir karbonatan, batugamping units, units and unit batugamping coral alluvium. Mapping regional geologic history began in the Middle Miocene the subsidence occurs with age batupasir unit N9 land subsidence in the environment. After that transgresive occupied that area. The carbonaceous sandstone unit deposited with age N10 - N13. Afterward, transgressive event happened and limestone deposited in age N13 - N16 and followed tectonic processes that formed up G. Ngemada fault. The next geological process is of regression in the early Late Miocene units that coral limestone deposited conformities on the limestone units. Coral limestone with age N17 - N19 formed in the inner shelf sedimentation environment. After the formation of coral limestone units, then geologic processes is tectonic processes that formed the geological structure of fault i.e. a Nglirian trust fault and a K. Nenger normal fault. Beside that, the minor graben structure in K. Bantos has formed as well. after that all the units of rock uplifted to the surface. Then, after uplifted, no depositional event again (non-deposition). In the Holocene era, it was happened precipitation of alluvium (Qa) due to exogenic process. Georesources of this area are limestone mining, springs, irrigation and farm fields and the use of soil as a tile-making materials as well. Whereas for geological disasters that happened was a landslide as a result of mining activities. Keywords: geomorphology, Stratigraphy, karst, transgresi, regression.