Geology of Bandungharjo Toroh District, Grobogan Regency, Central Java Province

Abstract

Fidiarini, R.H, 2008. Geology of Bandungharjo Toroh District, Grobogan Regency, Central Java Province. Geological Mapping Report, Unpublished, Geological Engineering Department, Engineering Faculty, Diponegoro University, Semarang, Central Java, Indonesia. Regional mapping administratively included in the subdistrict Toroh, Grobogan district, Central Java Province. Grobogan regional geology has been mapped by a geologist, but in general scale. This mapping aims to conduct geological mapping, more detailed. Geomorphology mapping area is divided into four units of geomorphology, ie strong unit denudasional wavy plains, undulating hills denudasional unit, undulating hills of structural units, and units of fluvial plains. The main rivers namely stadia old stadia with the appearance of the river meandering. Stratigraphy mapping area is divided into three units, from the old to the young as follows: napal unit, limestone units, and units with the formation of alluvial deposits are the Kalibeng Formation. Geological structures that work in the form of folds (sinklin asymmetry) and shears. Geological history began in Late Miocene (N16-N18). Environmental napal unit of sedimentation in the sea (continental slope) and its deposited process is influenced by the current turbidit. While limestone was deposited in shallow marine environment or the litoral zone. Tectonic processes are strong enough to folded Plistocene Pliocene resulting in the formation . It has resulted the appointment of hollow Kendeng late Plistosen. In the Holocene has been formed alluvial deposits formed by river activity. Georesources in this area is mixed napal cement industry. Meanwhile, geological disasters happened is mass wasting and rockslides. Keywords: geomorphology, Stratigraphy, structural geology.