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On intermediate igneous rocks Note: All information on soils were from the Land Resource Study 20 series of books (Volumes 1 to 5), published by the Land Resources Division, Ministry of Overseas Development , UK.
Three associations have been mapped on predominantly intermediate igneous rocks. Of these the Apas and Kennedy Bay Associations are very similar and should probably be combined, they are both formed on moderate to high hills. In contrast, Wullersdorf Association is formed on mountains.
The Apas Association is restricted to the Semporna Peninsula, where it occurs:
Parent materials comprise andesitic and dacitic lavas and ashes, which have been dissected into ridges with short steep slopes separated by narrow valleys up to 45 m deep.
The Kennedy Bay Association occurs extensively to the north and east of Lahad Datu, and on the Bagahak Range, northeast of Kennedy Bay. The Bagahak Range consists of hills and ridges with amplitudes rarely exceeding 150 m.
The Wullersdorf Association is extensive to the north of Tawau and it also occurs to the east of the Kalumpang estuary. It occurs on mountain ranges with prominent peaks including Magdalena, Lucia, Maria and Wullersdorf. The mountains are formed of a variety of parent materials broadly described as intermediate and acid igneous rocks. Paton (1963) describes soils on andesitic ashes, rhyolitic laves and dacitic lavas and ashes. |
