Dominant Weathering Profile Assessment of Kebo-Butak Volcanic Rocks in Gedangsari and Ngawen area, Yogyakarta, Indonesia

Fathan Hanifi Mada Mahendra; I Gde Budi Indrawan; sugeng sapto surjono

doi:10.22146/jag.57552

Dominant Weathering Profile Assessment of Kebo-Butak Volcanic Rocks in Gedangsari and Ngawen area, Yogyakarta, Indonesia

https://doi.org/10.22146/jag.57552

Fathan Hanifi Mada Mahendra⁽¹⁾, I Gde Budi Indrawan⁽²⁾, sugeng sapto surjono^(3*)

(1) Departemen Teknik Geologi, Universitas Gadjah Mada
(2) Departemen Teknik Geologi, Universitas Gadjah Mada
(3) Universitas Gadjah Mada
(*) Corresponding Author

Abstract

The Gedangsari and Ngawen area is predominantly composed of volcanic and volcaniclastic sequencesdistributed east – west direction of the northern parts of Southern Mountain. The massive tectonism as well as tropical climatein this region have been producing weathering profiles in varying thickness which inevitably affects thegeotechnical properties. This study aims to assess the dominant weathering profileof the lower part of Kebo-Butak Formation as well as evaluating the distribution of the discontinuity. In order to know the dominant weathering profile and discontinuity evaluation, this study utilizes a total of 26 panels from five stations investigated through a geotechnical data acquisition including the geological condition, weathering zones, joint distribution, and discontinuity characteristics. The result shows four types of dominant weathering profiles in lower part of Kebo-Butak Formation called as dominant weathering profile A, B, C, and D. Profile A, B, C consisted of a relatively identical weathering degree pattern of fresh, slightly, moderately, completely weathered zone with the variation of thicknesses. However, the weathering degree in profile D reached the residual soil degree controlled by more intensive joints. The fine-grained sedimentary rocks also tends to have smaller spacing, shorter persistence, and higher weathering degree of discontinuities as compared to coarse-grained sedimentary rocks.

Keywords

Dominant Weathering Profile, Kebo-Butak Formation, intensive joints, fine-grained sedimentary rocks

Full Text:

PDF

References

Abad, S. A. N. K., Mohamad, E., & Komoo, I. (2014). Dominant weathering profiles of granite in southern Peninsular Malaysia. Engineering geology, 183, 208-215.

Armaghani, D. J., Hajihassani, M., Mohamad, E. T., Marto, A., & Noorani, S. (2014). Blasting-induced flyrock and ground vibration prediction through an expert artificial neural network based on particle swarm optimization. Arabian Journal of Geosciences, 7(12), 5383-5396.

Dearman, W. (1974). Weathering classification in the characterisation of rock for engineering purposes in British practice. Bulletin of the International Association of Engineering Geology-Bulletin de l'Association Internationale de Géologie de l'Ingénieur, 9(1), 33-42.

Gumede, T. (2007). Measurement of typical joint characteristics in South African gold mines and the use of these characteristics in the prediction of rock falls. Journal of the Southern African Institute of Mining and Metallurgy, 107(5), 335-344.

Kalatehjari, R., Ali, N., Kholghifard, M., & Hajihassani, M. (2014). The effects of method of generating circular slip surfaces on determining the critical slip surface by particle swarm optimization. Arabian Journal of Geosciences, 7(4), 1529-1539.

Komoo, I. (1985). Engineering properties of weathered rock profiles in Peninsular Malaysia: Institution of Engineers Malaysia.

Komoo, I. (1998). Deep weathering: major cause of slope failure in wet tropical terrain. Paper presented at the Engineering Geology: A global view from the Pacific Rim.

Moye, D. (1955). Engineering geology for the Snow Mountain schema. Jour. Institution of Engineerers, Australia, 27, 281-299.

Pulunggono, A., & Martodjojo, S. (1994). Perubahan tektonik paleogen-neogen merupakan peristiwa tektonik terpenting di Jawa. Proc. Geologi dan Geoteknik Pulau Jawa, Yogyakarta, h, 37-49.

Rahardjo, W. (1983). Paleoenvironmental Reconstruction of the Sedimentary Sequence of The Baturagung Escarpment Gunung Kidul Area Central Java. Proceedings PIT XII IAGI. Yogyakarta, 6-8.

Raj, J. K. (2010). Soil-moisture retention characteristics of earth materials in the weathering profile over a porphyritic biotite granite. Am. J. Geosci, 1(1), 12-20.

Ruxton, B. P., & Berry, L. (1957). Weathering of granite and associated erosional features in Hong Kong. Geological Society of America Bulletin, 68(10), 1263-1292.

Şen, Z. (2014). Rock quality designation-fracture intensity index method for geomechanical classification. Arabian Journal of Geosciences, 7(7), 2915-2922.

Sudarno, I. (1997). Petunjuk Adanya Reaktifasi Sesar di Sekitar Aliran Sungai Opak, Perbukitan Jiwo dan Sisi Utara Kaki Pegunungan Selatan. Media Teknik, 19(1997).

Sumarso, T. I. (1975). Contribution to the Stratigraphy of the Jiwo Hills and Their Southern Surroundings (Central Java).

Surjono, S.S., (1995). Geologi Daerah Baturagung dan Sekitaranya, Kabupaten Gunungkidul, Daerah Istimewa Yogyakarta. Tugas Akhir Tipe Pemetaan di Jurusan Teknik Geologi FT UGM. Unpublished.

Surono, B. T., & Sudarno, I. (1992). Peta Geologi Lembar Surakarta-Giritontro, Jawa. Bandung: Pusat Penelitian dan Pengembangan Geologi.

Tating, F., Hack, R., & Jetten, V. (2015). Weathering effects on discontinuity properties in sandstone in a tropical environment: case study at Kota Kinabalu, Sabah Malaysia. Bulletin of Engineering Geology and the Environment, 74(2), 427-441.

Ulusay, R., & Hudson, J. (2007). The complete ISRM suggested methods for rock characterization, testing and monitoring. ISRM Turkish National Group, Ankara, Turkey.

Van Bemmelen, R. (1949). The geology of Indonesia (Vol. 1A). Nederland: The Hague, Martinus Nijhoff.

Van Gorsel, J. H., Kadar, D., & Mey, P. H. (1989). Central Java Fieldtrip.

Verma, A. K., & Singh, T. (2010). Modeling of a jointed rock mass under triaxial conditions. Arabian Journal of Geosciences, 3(1), 91-103.

Wilson, M. J. (2004). Weathering of the primary rock-forming minerals: processes, products and rates. Clay Minerals, 39(3), 233-266.

Zhao, J., Broms, B., Zhou, Y., & Choa, V. (1994). A study of the weathering of the Bukit Timah granite part A: review, field observations and geophysical survey. Bulletin of the International Association of Engineering Geology-Bulletin de l'Association Internationale de Géologie de l'Ingénieur, 49(1), 97-106.

DOI: https://doi.org/10.22146/jag.57552