A Reinterpretation of the Baturetno Formation: Stratigraphic Study of the Baturetno Basin, Wonogiri, Central Java

Purna Sulastya Putra, Eko Yulianto

Abstract


DOI:10.17014/ijog.2.3.125-137

This paper focuses on the Quaternary Baturetno Formation. An earlier research concluded that the black clay of the Baturetno Formation formed as a ‘palaeolake’ deposit. The ‘palaeolake’ was interpreted to form due to the shifting course of the Bengawan Solo Purba River in relation to Pliocene tectonic tilting in the southern Java. The stratigraphy of the Baturetno Formation was observed in the western part of the Baturetno Basin, and based on marker beds, the Baturetno Formation was classified into three units: (1) Gravel unit (GR) in the upper part, (2) clay unit (CU) in the middle part, and (3) sand-gravel unit (SG) in the lower part. There are floating gravel fragments of andesite, claystone, coral, and limestone with diameters of up to 10 cm in the clay unit. The particle size of sediment reflects the environment, but the lake deposition occurs under very quiet conditions. The occurrence of these fragments within the clay cannot be explained if the clay was deposited within a lake environment. The occurrence of floating fragments in the black clay of Baturetno Formation can best be explained through mudflow process. The cohesive strength of the mudflow is responsible for the ability of large fragments to float within the mud matrix. In general, the Baturetno Formation is inferred to be an alluvial fan deposit. The presence of sand, gravel, and mud are characteristics of alluvial fan deposits.


Keywords


Baturetno Formation; black clay deposits; mud flow deposit; alluvial fan

References


Blair, T.C. and McPherson, J.G., 1994. Alluvial Fan Process and Forms. In : Abraham, A.D. and Parsons, A.J., (eds.), Geomorphology of Desert Environments. Chapman & Hall, London. p.354-366.

Blissenbach, 1954. Geology of Alluvial Fans in semi-arid regions. Bulletin of Geological Society America, 65, p.175-190.

Boediarto, R., 1962. New Find Vertebrata Bearing Layers in the Wonosari and Wonogiri Areas, Central Java. Bulletin of GSI, 2.

Bull, B.W., 1977. The Alluvial Fan Environment. Progress in Physical Geography, p.222-270.

Chamyal, L.S., Khadkikar, A.S., Malik, J.N., and Maurya, D.M., 1997. Sedimentology of the Narmada alluvial fan, western India. Sedimentary Geology, 107, p.263-279.

Curry, R.R., 1966. Observation of Alpine mud flows in the Tenmile Range, Central Colorado. Bulletin of Geological Society of America, 77, p.771-778.

Gani, M.R., 2004. From turbid to lucid: a straightforward approach to sediment gravity flows and their deposits. The Sedimentary Record (A publication of the SEPM Society for Sedimentary Geology), 2 (3), p.4-8.

Lehmann, H.H., 1936. Morphologische studien auf Java. J. Engelhorus Nachf, Stuttgart.

Nemec, W. and Steel, R.J., 1984. Alluvial and Coastal Conglomerates: Their Significant Features and Some Comments on Gravelly Mass Flow Deposit. Sedimentary of Gravels and Conglomerate. CSPG Special Publication, p.1-31.

Pamungkas, S., 2000. Geologi dan telaah Geologi Kuarter daerah Eromoko dan sekitarnya, Kabupaten Wonogiri, Prop. Jawa Tengah. Laporan Skripsi Jurusan Teknik Geologi ITB Bandung.

Sharp, R.P. and Nobles, L.H., 1953. Mudflow of 1941 at Wrightwood, Southern California. Bulletin of Geological Society of America, 64, p.547-560.

Samodra, H., 2007. Korelasi antara morfogenesis dan perkembangan Lembah Sadeng dengan pola arah struktur geologi akibat tektonik di kawasan Kars Gunung Sewu, Kabupaten Gunungkidul, Yogyakarta. Tesis (S2), Program Studi Ilmu Pengembangan Kewilayahan Pertambangan dan Sumberdaya Mineral, Universitas Padjadjaran, 218pp.

Surono, 2005. Sejarah Aliran Bengawan Solo Hubungannya dengan Cekungan Baturetno Kabupaten Wonogiri, Jawa Tengah. Publikasi Ilmiah, 1 (1), p.77-87.

Surono, Samodra, H., and Sidarto, 2013. Hubungan Lembah Sadeng, Cekungan Baturetno dan Teras Bengawan Solo, Jawa bagian Tengah. Jurnal Sumber Daya Geologi, 23 (3).

van Bemmelen, R.W. 1949. The geology of Indonesia. I-A, Martnus Nijhoff, The Hague, 749pp.

Wiyono, S., 1992. Stratigrafi dan sedimentasi endapan Kuarter di daerah Eromoko, Wonogiri. Kumpulan Makalah PIT XXI IAGI, p. 437-461, Yogyakarta.


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