Marine geology of the East coast of Peninsular Malaysia

The survey was conducted along 2,475 kilometers of tract in the South China Sea offshore East Peninsular Malaysia to evaluate the presence of placer gold, tin and heavy minerals, as well as sand resources. Geophysical methods were employed, consisting of high resolution seismic profiling, side scan sonar and magnetics. These data were supported by analyses from 232 cores and 241 grab samples obtained in the 25,000 square kilometer survey area. The presence of heavy metals in the seafloor sediments was also examined in order to address environmental concerns that might arise if mining were to ensue.; The surficial sediments in the survey area ranged from clays to gravels, with the latter composed mostly of coral fragments and shell. Organics were relatively low, ranging from one to seven percent, with the highest values probably due to anthropogenic sources. The unconsolidated sediments below the seafloor were divided into seven units based on seismic stratigraphy, which also identified two lowstand erosional surfaces from the middle and late Pleistocene, respectively.; Quantitative sediment examinations showed the concentration of heavy minerals to be too low for mining purposes. Likewise, the gold and tin values were also very low and not of commercial grades. What little gold was present was confined to the very fine fractions, which mirrored its occurrence on land, adjacent to the survey area Although rich tin deposits on the adjacent peninsula are associated with coarse sands and gravel, similar sediments in the survey area show a paucity of tin.; Abundant sand resources appear to be present in the offshore area, with approximately eight billion cubic meters of sand available in sand mounds and ridges. With about 50 percent of Peninsular Malaysia's 1900 kilometers of shoreline undergoing varying degrees of erosion, the potential of these resources for beach reclamation is of great importance.; Anomalous occurrences of heavy metal concentrations were present in the silt and clay fractions of the sediments in some areas, and are suspected to be related to pollutants from industrial point sources introduced to the continental shelf by rivers.