Pustaka Ilmiah Universitas Padjadjaran

Abstrak

Studi Stratigrafi Pada Formasi Halang Berdasarkan Data Measured Section Pada Daerah Ciwaru, Ecamatan Ciwaru, Kabupaten Kuningan, Provinsi Jawa Barat

Miosen Akhir – Pliosen Awal tersingkap. Secara geografis terletak pada 108° 37′ 7” BT – 108° 38′ 21,73” BT dan 7° 04′ 12,54” LS – 7° 05′ 32,35” LS mencakup wilayah Desa Ciwaru, Kecamatan Ciwaru, Kabupaten Kuningan, Provinsi Jawa Barat. Berdasarkan Peta Geologi Regional lembar Majenang (Kastowo dan Suwarna, 1996), daerah penelitian merupakan bagian Formasi Halang. Penelitian ini menunjukkan litologi yang dominan berkembang di daerah penelitian berupa batupasir, batulanau, dan batulempung. Berdasarkan hasil pengukuran penampang stratigrafi batuan di lapangan dan melalui analisis fasies serta analisis studio berupa analisis petrografi dan analisis fosil, dapat disimpulkan bahwa terdapat 6 lithofasies yang mengacu pada klasifikasi fasies turbidit Mutti dan Ricci Lucchi (1972), yaitu fasies A4, fasies B1, fasies B2, fasies C, fasies D, dan fasies F ; 3 fasies pengendapan yang mengacu pada klasifikasi Nichols (2009), yaitu channel, levee, dan overbank; dan 2 sub-lingkungan pengendapan, yaitu kipas dalam (inner fan) dan kipas tengah (middle fan). Daerah penelitian berada pada Formasi Halang bagian atas didapat dari korelasi penampang stratigrafi secara vertikal kemudian mensebandingkan dengan stratigrafi regional dimana Formasi Halang bagian atas didominasi oleh perselingan batupasir-batulempung. Hasil korelasi lateral dari tiga lintasan penampang stratigrafi diinterpretasikan bagian barat daerah penelitian merupakan lingkungan pengendapan turbidit pada bagian kipas dalam (inner fan) dan semakin ke arah timur berada pada lingkungan pengendapan turbidit pada kipas tengah (middle fan).

This study is located in Ci Pahing River, Ci Kalong River, and Ci Taal River where the Early Miocene – Early Pliocene sedimentary rocks are exposed. Geographically the research area is located at 108° 37′ 7” – 108° 38′ 21,73”E and 7° 04′ 12,54” – 7° 05′ 32,35” S, and located in Ciwaru, Kuningan, West Java. Based on the Geological Map-Majenang (Kastowo & Suwarna, 1996), the research area is located in Halang Formation. This study shows that the lithologies that dominantly evolve in the research area are sandstones, siltstones, and claystones. Based on the results of the stratigraphic cross-section measurements, facies analysis, petrographic analysis, and micropaleontology analysis; it can be concluded that there are 6 lithofacies refers to the turbidite facies classification by Mutti & Ricci Lucchi (1972) which are: facies A4, facies B1, facies B2, facies C, facies D, and facies F; and there are 3 depositional facies refers to Nichols (2009) which are: channel, leeve, and overbank; and there are 2 sub-depositional environment which are: inner fan and middle fan. The research area is located in top of Halang Formation based from the vertical stratigraphic cross-section correlation, and then it compared to the regional stratigraphy where the top of Halang Formation is dominantly consist of sandstone-mudstone. The results from the lateral correlation of three stratigraphic measure section, it can be interpreted that in the south west of research area is the inner fan, and further to the east area it change to middle fan turbidite depositional environment.