The Archaean Provinces of India and their Comparison with those of Other Continental Shields

Doubts still exist in regard to the precise correlation of the Archaean formations in the different regions of the Indian Shield, either with one another or with those of other continental shield areas. In this paper the information available at present on the composition, classification and correlation of the Archaean formations in the several pre-Cambrian shields of the world is briefly reviewed, and a broad generalised correlation based on their absolute ages is given. The rock formations older than the Cambrians, which range in their absolute ages from about 600 to 3,500 million years as shown by radiometric determinations, have been classified broadly into 8 age groups and standard names have been suggested for each of the groups.