KDN 0560/82 ISSN 0126/5539 PERSATUAN GEOLOGI MALAYSIA .NEWSLETTER OF THE GEOLOGICAL SOCIETY OF MALAYSIA Jil. 8, No.5 (Vol. 8, No.5) Sep - Oct 1982 KANDUNGAN (CONTENTS) CATATAN GEOLOGI (GEOLOGICAL NOTES) J.K. Raj: An interesting exposure of unconsolidated sediments in the Kuantan Area of Pahang, Peninsula)" . Malaysia 187 Ibrahim Komoo: Ujian pantulan tukul Schmidt untuk menganggar kekuatan batuan granit di kawasan Pulau Pinang 193 Perbincangan (Discussion) C.S. Hutchison: Occurrence of a not unexpected dolerite in central Kedah - A Discussion 198 T.T. Khoo & B.K. Tan: Occurrence of a not unexpected dolerite in central Kedah - A Reply 199 ! ; PERHUBUNGAN LAIN (OTHER COMMUNICATIONS) i P.H. Stauffer: Alphabetising people's names - it's driving me crazy, Dr. Sigmund! 200 "' T.T. Khoo: Origin of Kinta limestone hills - by George! 202 PERTEMUAN PERSATUAN (MEETINGS OF THE SOCIETY) L. Sandjivy: Geostatistics and tin mining 204 I. Murata: Some aspects of earthquake prediction in Japan 211 J.F. McDivitt: Some aspects of mineral development in the Asean Region 212 GSM Economic Geology Seminar 1982 - Report and Abstracts 217 BERIT A PERSATUAN (NEWS OF THE SOCIETY) GSM Council 1983/84 Election 231 Workshop on Stratigraphic Correlation of Thailand & Malaysia 231 Keahlian (Membership) 234 Keahlian Profesional (Professional Membership) 234 Pertukaran Alamat (Change of Address) 235 Pertambahan Baru Perpustakaan (New Library Additions) 235 BERIT A-BERIT A LAIN (OTHER NEWS) Universiti Malaya Project Reports 1981 /82 236 Seminar on Phosphate Rock Potential in Southeast Asia 237 Symposium on Syngenesis & Epigenesis in Petrography & Ore Deposits 238 . Australian Mineral Foundation - Training Courses 1983 239 I Petroleum & Geological Engineering Course Offerings 1983 244 I .; AAPG Annual Convention 1983 245 Kursus-kursus Latihan (Training Courses) 248 Kalendar (Calendar) 249 DIKELUARKAN DWIBULANAN ISSUED BIMONTHLY PERSATUAN GEOLOGI MALAYSIA (GEOLOGICAL SOCIETY OF MALAYSIA) II Majlis (Council) 1982/83 Pegawai-pegawai (Officers) Presiden Khoo Teng Tiong, Jabatan Geologi, (President) Universiti Malaya, Kuala Lumpur Naib Presiden Leong Khee Meng, Carigali-BP, (Vice-President) P.O. Box 757, Kuala Lumpur Setiausaha Kehormat Tan Boon Kong, Jabatan Geologi, (Honorary Secretary) Universiti Kebangsaan Malaysia, Bangi Penolong Setiausaha Kehormat Mohd .. Ali Hasan, Jabatan Geologi, (Honorary Assistant Secretary) Universiti Malaya, Kuala lumpur Bendahari Chin Lik Suan, 13 Lorong SSl/llA (Honorary Treasurer) Kampong Jamil Rais, Petaling Jaya Pengarang Teh Guan Hoe, Jabatan Geologi, (Edi tor) Universiti Malaya, Kuala Lumpur Presiden Yang Dahulu Mohd. Ayob, Petronas (Immediate Past President) P.O. Box 2444, Kuala Lumpur Ahli-ahli Majlis, 2-tahun Abdul Aziz Hussin, Jabatan Kejuruteraan (Councillors, 2-year) Petroleum, Universiti Teknologi Malaysia, Jalan Gurney, Kuala Lumpur Khoo Kay Khean, Pejabat Penyiasatan Kajibumi, Kuala Kangsar, Perak Michael Leong, Petronas, P.O. Box 2444, Kuala Lumpur Yeoh Gaik Chooi, Esso Production, P.O. Box 857, Kuala Lumpur Ahli-ahli Majlis, l-tahun Abdul Malek Abdul Rani, Esso Produc­ (Councillors, I-year) tion, P.O. Box 857, Kuala Lumpur Ahmad Said, Petronas, P.O. Box 2444, Kuala Lumpur Choo Mun Keong, Malaysia Mining Corp. , P.O. Box 936, Kuala Lumpur Gan Ah Sai, Jabatan Penyiasatan Kaji­ • humi, Bang. Ukor, Jalan Gurney, Kuala Lumpur Juruodit Kehormat Peter Chew (Hon. Auditor) ***** First published 26 Jan. 1983 Printed by Art Printing Works Sdn. Bhd., 29 Jalan Riong, Kuala Lumpur 187 CAT ATAN GE 0 LOG I (G E 0 LOG I CAL NOT E S ) AN INTERESTING EXPOSURE OF UNCONSOLIDATED SEDIMENTS IN THE KUANTAN AREA OF PAHANG) PENINSULAR MALAYSIA J.K. RAJ, Jabatan Geologi, Universiti Malaya, Kuala Lumpur Abstract Unconsolidated sediments~ exposed in a recent slope cut in the Kuantan area~ can be subdivided into a lower unit (of approximately 3 to 6 m thick) of alternating~ horizontal to gently dipping layers of coarse sand and sandy clay~ and an upper unit (of approximately 3 to 5 cm thick) of homogenous clayey sand. The lower unit~ which uncon­ formably abuts against weathered granite~ and unconformably overlies weathered basalt~ is likely to be of a littoral or fluvial origin while the upper unit is likely be of a fluvial or aeolian origin. It is recommended that these sediments be examined palynologically as the results would raise interesting speculations on the Quaternary of Peninsular Malaysia. Introduction In the Semambu Industrial Estate of Kuantan, Pahang has been recently exposed a sequence of unconsolidated sediments that abut against weathered granite and overlie weathered ba~alt. This exposure is seen in a slope cut made into a sma l ridge that is approximatel~ located at the intersection of latitude 1 5 51' 25" N and longitude 103 19' 27" E (Figure 1). The base of the cut is located 26.3 m (119 feet) above the present sea-level (determined by a "pocket theodolite" survey), while the cut itself has a maximum height of 10.6 m. The upper surface of o the cut forms a gently sloping surface that has a slope of 4 . Description of exposure In the scaled sketch of the northern part of the exposed cut (Figure 2) can be seen the outcrop patterns, and characteristic features of the different lithologies present that include weathered granite, weathered basalt and unconsolidated detrital sediments. The weathered granite shows an approximate domal shaped outcrop • and is identifiable by the presence of coarse grained, angular, quartz crystals and angular, kaolinized feldspar grains. The weathered granite shows mottled red/yellow colours and consists of sand sized quartz grains embedded in a matrix of mainly clay sized particles (that have been derived from the alteration of feldspars and other primary minerals) (Figure 3). The weathered basalt, however, shows a very gently sloping (subhorizontal) upper surface and is identifiable by its characteristic variegated, bluish to purplish colour and silty clay texture (Figure 3). Unconformably, resting against the weathered granite, and overlying the weathered basalt (Figure 2) can be seen a sequence (of approximately ISSN 0126-5539 Warta Geologi~ vol. 8~ no. 5~ Sep-Oct 1982 188 3 to 6 cm thick) of alternating, horizontal to gently dipping layers of buff coloured, coarse sand and variegated, bluish to orange coloured, sandy clay. These layers are of variable thicknesses (from 15 to 150 em), though generally decreasing in thickness down-dip. A thin layer (of about 3 cm thick) of iron cemented quartz grains is furthermore, seen along the contact between a coarse sand layer and the. weathered basalt (Figure 2). The coarse sand layers are poorly sorted and consist largely of angular, fine to coarse sand sized, quartz grains with some clay (Figure 4), while the sandy clay layers consist mainly of clay sized particles with some silt and sand-sized angular quartz grains (Figure 4). Overlying the sequence of alternating coarse sands and sandy clays, and covering the outcrop of the weathered granite (Figure 2), is seen a thick, buff coloured layer of clayey sand (of approximately 3 to 5 m thick). This layer is devoid of sedimentary structures and consists of angular, fine to coarse sand sized, quartz grains and clay (Figure 4). " Metalled rood Location of slope cut o I Kilometre b:::=:d Figure 1. - Location map of the slope cut exposure of unconsolidated sediments in the Semambu Industrial Estate of Kuantan. .' " 100 100 90 90 80 80 70 ~ 70 sand (4' i 60 i 60 .."- eCD CD Q. .... Q. CD 50 .~ 50 ~ I .5! 1 !! ::J // ::J e // e § 40 § 40 // u u // // // // 30~ 30 l( Sandy clay (6' __ -~- ~........" -- 1 / I Weathered basalt ~ 1 20~ 11f.' ~ 20 I / '" / 1 / I, 10~ Ill' / Sandy clay (3' 10 " .... ~ ..... .;' "" "" .- --- 1.:::' ¢ -2 -I 0 2 3 4 5 6 7 8 9 ¢ -2 -I 0 2 3 4 5 6 7 8 9 Figure 4- Groin size distributions of the unconsolidated Figure 3- Groin size distributions of weathered granite and sediments. Cummulative curves on semi-log paper. weathered basalt. Cummulative curves on semi-log paper. Note: Numbers in brackets refer to sample numbers. Note: Number in brackets refer to sample numbers. 5 N 154 • • 4f r,-154 :;; ........•.......•.......•.•..........................................•...•.........•.......•.........•......................................... ,.4 !::: .. 42.4 ::: :,,7 ~ ;~~~~~~~~ill~i@~~~~~~JJjjj~~~~~~JJjj~~~~~~~~~~~@~~~~~~~~~~~~~~t~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~:::.. - + + ,..~~.gt'tR-:qUL0L&LU.bili:::;:::;:;;:~::a.~~.·.·.·.· .'. '~";~~~:.:~~~:.:~l.;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~m~u~~~~UU~~~~~~~~~~~~~~~~~~~~~~~.·~~~~~~.~~@~@~@m~m;~;;:;::::.. .'.• ~=*~~:~.==»:.;.:.:«::~:~:*"=:~:~:=*:~~.~:f." ........ *.~~~~;w;:::w..... ~ .. l;;; ++++ ++~+ ++~1Ji1;~~~ii~!~~x;~~~~~:~:;:;;~~; :::! a ...,.. : : .... ::."'. ."..".. _ ~ X X X X X X X X X X X X X X X X X X " - + + + +.+ + + -.;;i!>-~!.t:.':::.'i·:·::::"":"'":"""",..,.·,.,,·""·:""'·""·~T X X X X 2. X X X X X X X X X XXXx X X X X X X X X X X X X X X X X X 119'" f 124 + + + +1 + + + + ",.~~~ .. ~:Liii;~(;;;::.:2>;-;;·.~·.j:~,..· X X X X X X X X X X X X X X X X 119 ..- 0' 10 20 tt. Weathered granite ....... -- Lithological boundary 1+ + +1 I , ~ Weathered basalt ./ Loyer of iron-cemented quartz groins Vertical scale horizonlal scale ....- o 2 4 6metres CJ Sandy cloy ./ ...... Bench level of c~t ~ Figure 2 - Scaled sketch of the recent slope cut exposure Coarse sand ~" Covered ~ of unconsolidated sediments in the Semambu Clayey sand ·2 Sample number Industrial Estate of Kuantan, Pohang. " 191 Discussion and Interpreations