Pustaka Ilmiah Universitas Padjadjaran

Abstrak

Petrogenesis Batuan Metamorf Daerah Cigaber Kecamatan Cihara, Kabupaten Lebak Propinsi Banten

Daerah penelitian berada pada koordinat 106° 6′ 31,7268″ BT – 106° 8′ 22,7364″ BT dan 6° 48′ 30,0024″ LS – 6° 47′ 14,874″ LS. Secara administratif, termasuk pada Daerah Cigaber, Kabupaten Lebak, Propinsi Banten. Penelitian ini menjelaskan tentang keterbentukan komplek metamorf pada daerah penelitian berdasarkan pendekatan petrografi, metode pengamatan lapangan. Hasil penelitian menunjukan bahwa komplek metamorf terdiri atas sekis klorit, muskovit, biotit, garnet, aktinolit, dan hornblenda, yang berasal daro protolith pelite-semipelite-psamite dan batuan beku mafik. Berdasarkan mineral assemblage, komplek metamorf ini terbentuk pada suhu 2000C – 5500C dengan tekanan 2 Kbar – 5,5 Kbar. Termasuk dalam fasies sekis hijau – amfibolit bawah, termasuk ke dalam tipe metamorfisme regional.

Geographically research area were in 106° 6′ 31,7268″ – 106° 8′ 22,7364″ EL and 6° 48′ 30,0024″ – 6° 47′ 14,874″ SL coordinate. Administratively research area was in Cigaber District, Lebak Resident, Banten Province. This research provides about metamorphic complex forming in study area based on petrogrphy and field oriented method. This research shows that metamorphic complex consist of chlorite schist, muscovite, biotite, garnet, actinolite, and hornblende, the protolith of these rocks are pelite-semipelite-psamite rock and mafic rock, according to assemblage minerals in these rocks, this complex was formed in temperature between 2000C – 5500C and the pressure between 2 Kbar – 5,5 Kbar. Metamorphic complex in research area belonging to greenschist – lower amphibolite facies. Metamorphic complex in research area belonging to regional metamorphism type.