The Collision of the Sibumasu and Indochina terranes.

Conceptual cross-section illustrating fromation of the Bentong-raub Suture by subduction of the Palaeo-Tethys Ocean and collision of the Sibumasu and Indochina terranes. Palaeo-Tethys opened in the Devonian, when Indochina and other Chinese blocks separated from Gondwana (in the late Sakmarian, Permian) and closed in the Late Triassic (After Metcalfe, 2000).

Brachiopod Spinomartinia sp. from Perlis

Brachiopod belonging to Spinomartinia sp. discovered in thickly bedded dark grey mudstone at Km 5, of the Kaki Bukit-Wang Klian trunk road, indicate of early Permian age of Sakmarian substage in the Singa Formation.