Abdul Rahim Samsudin

Paleomagnetism of Peninsular Malaysia

Abstract Paleomagnetic results from Upper Jurassic to Paleocene rocks in Peninsular Malaysia show counter clockwise (CCW) rotations, while clockwise rotations (CW) are predominantly found in older rocks. Continental redbeds of the Upper Jurassic to Lower Cretaceous Tembeling Group have a post folding remagnetization, giving a VGP at N54°E29°, corresponding to approximately 40° of CCW rotation relative to Eurasia and 60° CCW relative to the Indochina block (Khorat Plateau). Samples from Cretaceous to Paleocene mafic volcanics of the Kuantan dike swarm and the Segamat basalts give VGPs at N59°E47° and N34°E36°, respectively. These Malayasian data are indistinguishable from the Late Eocene and Oligocene VGPs reported for Borneo and the Celebes Sea and are similar to the Eocene VGPs reported for southwest Sulawesi and southwest Palawan. The occurrence of CCW deflected data over this large region suggests that much of Malaysia, Borneo, Sulawesi, and the Celebes Sea rotated approximately 30° to 40° CCW relative to the Geocentric Axial Dipole (GAD) between the Late Eocene and the Late Miocene, although not necessarily synchronously, nor as a single rigid plate. These regional CCW rotations are not consistent with simple extrusion based tectonic models. CW declinations have been measured in Late Triassic granites, Permian to Triassic volcanics, and remagnetized Paleozoic carbonates. The age of this magnetization is poorly understood and may be as old as Late Triassic, or as young as Middle or Late Cretaceous. The plate, or block rotations, giving rise to these directions are correspondingly weakly constrained.

Thermal springs of Malaysia and their potential development

Abstract The study on the potential development of hot springs for the tourism industry in Malaysiawas conducted. Out of the 40 hot springs covered, the study identified 9 hot springs having a high potential for development, 14 having medium potential and the remaining 17 having low or least potential for development. This conclusion was arrived at after considering the technical and economic feasibility of the various hot springs. Technical feasibility criteria includes geological factors, water quality, temperature and flow rate. The economic feasibility criteria considers measures such as accessibility, current and market potentials in terms of visitors, surrounding attractions and existing inventory and facilities available. A geological input indicates that high potential hot springs are located close to or within the granite body and associated with major permeable fault zones. They normally occur at low elevation adjacent to topographic highs. High potential hot springs are also characterised by high water temperature, substantial flowrate and very good water quality which is important for water-body contact activities such as soaking. Economic criteria for high potential hot springs are associated with good accessibility, good market, good surrounding attractions like rural and village setting and well developed facilities and infrastructures.

Environmental Site Assessment at TPH Contaminated Site: A Malaysian Case Study

This paper introduces the Malaysian Contaminated Land Management and Control Guidelines and one case study on Environmental Site Assessment (ESA) conducted at one contaminated site in Malaysia. The site was contaminated with spent transformer oil, i.e. Total Petroleum Hydrocarbons (TPH). Five types of environmental samples were collected, i.e. surface soil, surface water, subsurface soil, groundwater and air. Samples were analysed for Total Petroleum Hydrocarbons (TPH) and fractioned into different carbon fractions namely C6-C9, C10-C14, C15-C28 and C29-C36. Risk Assessment was also performed utilising Risk Based Corrective Action (RBCA) method. The drilling bore-log showed that the site is located on residual weathered meta-sediment rock with thick clayey silt. The study discovered the spent oil was trapped inside the made layer gravel within ~22 to 60 cm on top of the residual clayey silt. Chemical results showed TPH in surface soils ranged from 1310 to 26747 mg/kg with the average value of 17200 mg/kg. In surface water (inside the contaminated area), the concentration of TPH was measured in between of 1 to 2646 mg/L (averaging 454 mg/L). RBCA analysis showed that indoor and outdoor air were the pathways with lower risk level with all risk values (Hazard Quotient, HQ) below the upper limit of 1.0. Baseline risk level for soil is slightly higher than the upper limit level with a risk of 1.5. Critical pathway is through groundwater with baseline risk level significantly higher than the upper risk level with a value of 5.4E+6.

Study of movement of the western and central belts of Peninsular Malaysia using GPS data analysis

Since the large earthquakes in Sumatera and Nias, there were some tremors incidents at Bukit Tinggi. Therefore, a study on the earth’s crust movement and the effects of the earthquake in Indonesia on the tectonic blocks of Peninsular Malaysia have been carried out using GPS data analysis. GPS data from five MyRTKnet stations within Peninsular Malaysia have been analyzed to monitor the movement of two major tectonic blocks of Peninsular Malaysia which are the western belt represented by the Behrang (BEHR) and UPM Serdang (UPMS) stations and the central belt represented by Bentong (BENT), Jerantut (JRNT) and Temerloh (TLOH) stations. GPS data recorded from 2005 to 2010 were analysed based on horizontal and vertical displacements of the respective stations by using Trimble Business Centre (TBC) software. Based on the results of accumulated displacements of recorded GPS data from January 2006 to December 2013, it shows that the western belt which represented by UPMS has shifted 0.096m towards northwest with c...

Analysis of Cheshire basin by gravity method: Some preliminary results

Gravity data acquired from Cheshire basin located in the northwestern part of the United Kingdom were processed and analysed to determine the structural pattern within the entire sedimentary basin. A total of 753 gravity data were obtained from the British Geological Society and with the aid of Oasis Montaj software, maps of Bouguer anomaly, isostatic and total horizontal derivative were obtained for qualitative and quantitative interpretation in determining the fault trend and the tectonic system of the study area. The positive Bouguer anomaly region found in the northwest of the study area is associated with the high density sedimentary rocks while the negative region in the southern part corresponds to low density sediments. The regional and local isostatic maps with different cut-off wavelengths reflect changes in anomalies corresponding to different types of sedimentary rocks. The general trends of faults in the Chesire basin are shown in the total horizontal derivative map of the Bouguer gravity val...

Analysis of ancient-river systems by 3D seismic time-slice technique: A case study in northeast Malay Basin, offshore Terengganu, Malaysia

Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This study is based on the analysis of high-resolution, shallow (seabed to 500 m depth) 3D seismic data which generated three-dimensional (3D) time slices that provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The study area is in the northeast of Malay Basin about 280 km to the east of Terengganu offshore. The Malay Basin comprises a thick (> 8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1–5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humid-tropical climatic setting. This study focuses on the Pleistocene to Recent (500 m thick) succession, which comprises a range of seismic facies analysis of the two-dimensional (2D) seismic sections, mainly reflecting changes in fluvial channel s...

Application of vertical electrical sounding (VES) in subsurface geological investigation for potential aquifer in Lahad Datu, Sabah

40 Vertical Electrical Sounding (VES) stations were established to investigate the subsurface geology and aquifer potentials in the area of Dent Group sedimentary rock. Dent Group sedimentary rock consists of Sebahat, Ganduman and Togopi Formation with the age of Late Miocene until Pleistocene. VES technique was performed by measuring the resistivity change with depth. The resistivity measurements were conducted using ABEM SAS 300C Terrameter by using Schlumberger electrode configuration with maximum current electrode separation of 500m. Interpreted VES data in the Sebahat Formation produces three to four geo-electrical resistivity layers. Most of the geo-electrical layers show low resistivity value (1-10 Ohm-m) that indicate the formation was mainly made of clay or shale materials. VES results in the Ganduman Formation indicates that the formation dominated by layers of sandstone and mudstone mixed with siltstone layer. Generally, the Ganduman Formation gives four to five geo-electrical resistivity layer...

Results of Geoelectrical Soundings for Mapping of a Marine Clay Along the Tangkak-Pagoh Highway Johor, Malaysia

Geoelectrical resistivity soundings conducted along the north-south expressway in the Tangkak-Pagoh area during its construction enabled the mapping of a marine clay which was present in alluvium. The apparent resistivity curves of the marine clay area, were characterised by low apparent resistivity values falling to almost zero, and a characteristic shape which was different from areas of weathered metasediments and weathered granite adjacent to this area. Apparent resistivities for both metasediments and granite were intermediate to high, with a distinct upward convex curve for metasediments and a flat upward convex curve for granite. Quantitative interpretation was able to distinguish between an upper and a lower clay horizon, which have differentconsistency and fine sand content. The thickness of the upper clay horizon, which varies between 8.0 m to 9.0 m according to borehole data showed good agreement with that obtained by resistivity soundings. The base of the lower clay horizon remained undetected by the resistivity soundings because of its very low specific resistivity. Using the thickness of weathered layers as observed along the road cuttings as a guide, good agreement between field data and calculated values was obtained in determining the specific resistivities and individual layer thicknesses for the granite and metasediment weathering profiles.