Bulletin of the Geological Society of Malaysia, Volume 4, June, 1971, pp. 15 – 37
United States Peace Corps assigned to The Geological Survey of Malaysia
Abstract: The Kinta Valley is a large alluviated tract in the State of Perak, flanked by granite ranges east and west. Bedrock in the valley itself is mainly crystalline limestone, with minor clastic metasediments. The valley is drained by the southward-flowing Kinta River (with a gradient of about 5 ft/mi), and its tributaries, the main ones entering from the east. Thickness of alluvium in the valley increases southward from about 20 feet near Ipoh to more than 100 feet in the southern part, giving a southward slope for the bedrock surface of about 10 ft/mi. Before artificial deviation, the Kinta River had a sinuosity of about 1.3, transitional between a straight and a meandering channel.
Thirty-eight alluvial tin mines near Kampar were examined and their alluvial sections studied. The unconsolidated deposits exposed included ‘ granite wash ‘ (partly eluvial); stratified sand, silt and clay; peat and peaty sediments; and mine tailings. Multiple, graded depositional sequences, up to a maximum of four, were characteristic. The sections at three mines are described in detail.
Some 139 samples from 27 mines were analyzed for size distribution (by sieving) and for heavy mineral content (by bromoform separation). Heavy mineral content ranged from 0.05% to 3.2%, with a mean of 0.59%. Scatterplots show that a high content of heavy minerals tends to be associated with coarse mean grain size (Mz) and with low or negative values of skewness (Skl), but the relationships are not simple and no single parameter is a good index to heavy mineral concentrations.
Many characteristics of the unconsolidated deposits (including the graded depositional sequences; current bedding and other primary structures; abundance of organic material; and generally positive skewness values) are compatible with and strongly suggestive of fluvial deposition. It is likely that the deposits, apart from eluvial and residual portions, represent the channel and topstratum deposits of a river or rivers of low to transitional sinuosity.