WANDERING OF SRI LANKA FROM PRECAMBRIAN TO RECENTAuthors: Jinadasa Katupotha
Many earth scientists have postulated that Sri Lanka is a Precambrian landmass composed mainly of Proterozoic rocks. Published worked by such previous workers divulged that the recent geochronological data of Sri Lanka suggest that: (1) Highland/Southwestern Complex (H/SWC) sedimentation as well as igneous activity in the form of basic lava flows, basic sills and dykes took place ~ 2,000 Ma ago; (2) intrusion of the earliest granitoids into the Highland Complex (HC) took place 1,940 to 1,800 Ma ago; (3) orthogneisses of the Wanni Complex (WC) were intruded between 1,100 and 670 Ma; (4) orthogneisses of the Vijayan Complex (VC) were intruded between 1,040 - 1,030 Ma; and (5) highgrade regional metamorphism of the HC, VC and WC took place between 610 - 455 Ma. With the opening of the Indian Ocean in Early Cretaceous (145-100 Ma), Sri Lanka emerged as a separate landmass attaining its present outline. Published evidences clearly indicate that by Upper Jurassic (163.5-152.1 Ma), Sri Lanka was located within 65º S-67ºS and 32ºE - 36ºE. Since then, Sri Lanka gradually drifted northeastwards since Cretaceous, and reached its present position between 5º52´N - 9º54´N and 79º30´E - 81º55´E due to continental breakup and the dispersal of Gondwanaland by end of the Quaternary. Such changes are a result of Permo-Triassic igneous and tectonic activity, Permo-Triassic magnetism, areas of subduction, rifting and development of spreading and expansion of the Indian Ocean as well as periodic migration of upwelling mantle flow. Thus, this is a review describes the geographical position of Sri Lanka during the evolution of the Indian Ocean.
Keywords: Evolution, Wandering, Precambrian, Sri Lanka, Landmass, Geological Time
How to Cite: Jinadasa Katupotha,, (2019). WANDERING OF SRI LANKA FROM PRECAMBRIAN TO RECENT.WILDLANKA, 7(4):Pages 209-232
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