Lateritic soils of Peninsular Malaysia


Author : S. Paramananthan and M. TharmarajanPublication : Bulletin of the Geological Society of MalaysiaVolume : 16Page : 87-97Year : 1983


Description

Bulletin of the Geological Society of Malaysia, Volume 16, Dec. 1983, pp. 87 – 97 

 

Lateritic soils of Peninsular Malaysia

S. PARAMANANTHAN1 and M. THARMARAJAN2

1Associate Professor, Universiti Pertanian Malaysia, Serdang, Selangor, formerly Head, National Soil Survey, Dept. of Agriculture, Peninsular Malaysia

2Senior Agriculture Officer, Soil Survey Unit, Dept. of Agriculture, Kuantan, Pahang

 

Abstract: The term ‘laterite’ was first introduced by Buchanan in 1807 to describe a variegated material which occurred in South lndia. This material when exposed hardens irreversibly. However, the terms ‘laterite’ and ‘laterite soils’, today have varied definitions. In fact any red coloured material rich in iron-oxides has been described as ‘laterite’, resulting in a lot of confusion in the literature. In order to overcome this, new terms such as plinthite, petroplilhile, pallid zone and iron-coated materials are defined as used by Soil Scientist.

Two types of ‘laterite soils’ are found in Malaysia. Iron coated materials formed by the intense weathering, leaching and accumulation of iron further down the weathering profile. Such ferruginous materials are often red coloured and retain their original rock structure, at least in part. The second type of ‘laterite soils’ found in Peninsular Malaysia consists of sub-rounded and rounded ferruginous gravels overlying the weathered sapprolite often unconformably. These types of soils often form cappings on hills. The erosion of these materials and dissection of the landscape results in two distinct catenal relationships between the materials and erosion products. There is some disagreement among soil scientists as to the process which gave rise to the resultant landscapes. 

It is believed that, intensive tropical weathering during the Tertiary resulted in the formation of the reddish coloured soils with their iron-coated materials and their underlying plinthite (or laterite as defined by Buchanan). Subsequent dissection and erosion of the iron-coated materials gave rise to three geomorphic surfaces. These surfaces are probably related to the changes in sea-Ievels during the Pleistocene.