Warta Geologi, Vol. 50, No. 1, April 2024, pp. 8-14
John Kuna Raj
No. 83, Jalan Burhanuddin Helmi 2, Taman Tun Dr, Ismail,
60000 Kuala Lumpur, Malaysia
Email address: jkr.ttdi.tmc@gmail.com
Abstract: The Eocene to Oligocene Batu Arang Beds outcrop within an approximately triangular basin covering some 15 km2 and comprise stiff, structureless clays to well laminated and fissile shales inter-bedded with fine to coarse sandstones and several coal layers. The shales are often silty and even sandy and contain abundant carbonaceous material. The coal mostly occurs as thin laminae, though two thick seams, mined by open-cast and under-ground methods from 1915 to 1960, are found in the eastern part of the basin. To determine the weatherability characteristics of the shales, three samples (A, B and C) were collected at the western wall, and one sample (D) at the eastern wall, of an open-cast shale pit. Samples A and D are located some 10 m, and 5 m, below the ground surface, whilst samples B and C are 10 m, and 16 m, stratigraphically below sample A. Samples A, B and C, and D have average dry unit weights of 16.64, 14.49, and 15.40, kN/m3 and average apparent porosities of 26.2%, 35.7% and 31.7%, respectively. Slake durability indices of all samples for one standard cycle of wetting and drying (Id1) are between 98.3% and 99.3%, and for two standard cycles (Id2), between 96.7% and 98.9%. Durability indices for three standard cycles (Id3) are between 95.1% and 98.2%, and for four standard cycles (Id4), between 93.3% and 97.6%. The indices lead to the conclusion that the shales are of high to extremely high durability and suitable for use as highway embankment or construction material. The high durability classification is supported by recent excavations at an overburden dump where relatively fresh shale blocks with little disaggregation or disintegration are exposed even after being buried for 78 to 85 years.
Keywords: Batu Arang Beds, Eocene to Oligocene strata, shales, slake durability indices
REFERENCES
Ahmad, M.K., 1993. Tertiary palynomorphs from Batu Arang, Malaysia. Abstracts, 1993 Annual Conference. Warta Geologi, 19(3), 116.
AIT, Asian Institute of Technology, 1981. Laboratory Manual for Rock Testing. Geotechnical & Transportation Engineering Division, Asian Institute of Technology, Bangkok. 205 p.
Azman Kassim & Edy Tonnizam Mohammad, 2007. Laboratory study of weathered rock for surface excavation works (Kajian makmal ke atas batuan terluluhawa untuk kerja-kerja pengorekan permukaan). Report Research Vote 75055, Civil Engineering Faculty, Universiti Teknologi Malaysia. 55 p.
CDOT, Colorado Department of Transport, 2015. Standard method of test for determining the durability of shales for use as embankments. https://www.codot.gov/business/.
Edy Tonnizam Mohamad, Rosli Saad, & Seyed Vahid Alavi Nezhad Khaili Abad, 2011. Durability assessment of weak rock by using Jar Slaking Test. Electronic Journal of Geotechnical Engineering, (EJGE), 16(O), 1319-1335.
Franklin, J.A. & Chandra, R., 1972. The slake durability test. International Journal Rock Mechanics & Mining Sciences, 9, 325-341.
ISRM, International Society for Rock Mechanics, 1979. Suggested methods for determining water content, porosity, density, absorption and related properties and swelling and slake durability index properties. International Journal of Rock Mechanics, Mineral Science and Geomechanics, Abstracts, 16, 141-156.
Johnson, R.B. & DeGraff, J.V., 1988. Principles of Engineering Geology. John Wiley & Sons, New York. 512 p.
Law, W.M., 1961. The Batu Arang Coalfield, Selangor. Bachelor of Science (Honors) Thesis, Department of Geology, University of Malaya, K.L. 60 p.
Malayan Collieries Limited, 1950. A Description of the Property, Operations and Social Organization at Batu Arang Colliery. 15 p.
Morgenstern, N.R. & D.K. Eigenbrod, 1974. Classification of argillaceous soils and rocks. Journal Geotechnical Engineering Division, American Society of Civil Engineers, 100, 1137-1156.
Raj, J.K., 1994. Uniaxial compressive strengths of Tertiary sedimentary rocks from the Batu Arang area, Selangor Darul Ehsan. Warta Geologi, 20, 1-5.
Raj, J.K., 1995. Point load strengths of Tertiary sedimentary rocks from the Batu Arang area, Peninsular Malaysia. Malaysian Journal of Science, 16B, 39-47.
Raj, J.K., 1998. Tectonic evolution of the Tertiary Basin at Batu Arang, Selangor Darul Ehsan, Peninsular Malaysia. Bulletin of the Geological Society of Malaysia, 42, 197-210.
Raj, J.K., 2020. Slake durability indices of fresh shales and sandstone from the Gemas Formation, Ayer Hitam, Johor Darul Takzim. Warta Geologi, 46(1), 1-5.
Raj, J.K., Tan, D.N.K. & Wan Hasiah Abdullah, 2009. Cenozoic Stratigraphy. In: Hutchison, C.S. & Tan, D.N.K. (Eds.), Geology of Peninsular Malaysia, University of Malaya & Geological Society of Malaysia, Kuala Lumpur, 131-172.
Renwick, A. & Rishworth, D.E.H., 1966. Fuel Resources (Coal, Lignite and Petroleum) in Malaya. Geological Survey Department, West Malaysia, Ipoh. 123 p.
Roe, F.W., 1951. The Geology and Mineral Resources of the Neighbourhood of Kuala Selangor and Rasa, Selangor, Federation of Malaya, with an Account of the Batu Arang Coalfield. Memoir 7, Geological Survey Department, Federation of Malaya. 163 p.
Stauffer, P.H., 1973. Cenozoic. In: Gobbett, D.J., & Hutchison, C.S. (Eds.), Geology of the Malay Peninsula, Wiley-Interscience, USA, 143-176.
Wong, J.M., Abdul Ghani Md Rafek & T.L. Goh, 2018. Issues in engineering geological classification of weathered sedimentary rocks: Case study of Kati Formation, Parit, Perak. International Journal of Engineering & Technology, 7, 131-135.
Zainab Mohamed, Abd Ghani Rafek & Ibrahim Komoo, 2007. Characterization and classification of the physical deterioration of tropically weathered Kenny Hill rock for civil works. Electronic Journal of Geotechnical Engineering, 12, 1-10.