ප්‍රාග් ඓතිහාසික ජනාවාස ව්‍යාප්තව පැවති දේශගුණ කලාප-Sri lankan Prehistory Zone Map

Sri lankan Prehistory Zone Map

Sri Lanka’s geological zones

Geologically looking, 9/10 of Sri Lanka comprises of highly crystalline rocks of more than 570 million years ago from the Precambrian era. The rest 1/10 comprises of sedimentary formations such as limestone, sands and clay of the Jurassic period and tertiary and quaternary periods. In the northern zone, a layer of limestone formed during the Miocene epoch could be traced. Precambrian rocks could be divided into 4 main categories based on their rock types, isotopic characteristics and structures.

1. Highland complex: the central highlands and northeast and south-west of the island.
2. Wanni complex: also called the Western Vijayan complex, comprises of the lowlands west of the Highland complex.
3. Vijayan complex: also called the Eastern Vijanyan complex, consists of the land east of the Highland complex.
4. Kadugannawa complex: centrally located in the Highland complex, the internal rocks are separate to that of the Highland complex.