Page 78 - Sumatra Geology, Resources and Tectonic Evolution

PRE-TERTIARY VOLCANIC ROCKS 65

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(e) LATE CRETACEOUS

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(d) JURASSIC-EARLY CRETACEOUS
oyla

(C) MIDDLE-LATE TRIASSIC

(b) AUSTRALIA'S POLAR WANDERING PATH

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Meso-

(a) EARLY PERMIAN PALAEOGEOGRAPHY
Fig. 6.2. Cartoons illustrating significant volcanic events in the geological evolution of Sumatra from its dispersal from Gondwana to the collision of the Bentaro-Saling
Oceanic Volcanic Arcs. (a) Gondwana Margin Break-up Volcanicity (V, volcanic localities) at the Gondwana-Cathaysia interface after the opening of Meso-Tethys in the
Early Permian. In this reconstruction the West Sumatra Block is still in position between Cathaysia and the Greater Sula Spur. Figure based on Figure 4.21 and Charlton
(2001). (b) The advances and retreats of Gondwana shown by the palaeomagnetic record for Australia (after Klootwijk 1996). Gondwana reconstruction by Charlton
(2001). (c) Palaeogeographic reconstruction of Sumatra and the Malay Penisula in the Mid-Late Triassic (from Fig. 4.25). The Pahang Volcanic Belt (V, volcanic
localities) is shown in the Semantan Basin. (d) Sumatra in the Jurassic-Early Cretaceous showing the Plutonic Arc, the Woyla Foreland Assemblage, the Meso-Tethys
and the Bentaro-Saling Arc with the Woyla Accretionary Complex. (e) In the Late Cretaceous the Bentaro-Saling Oceanic Arc has collided with and has been overthrust
onto Sumarta as the Woyla Nappe. Collision was followed by the resumption of subduction in the Late Cretaceous.