Paper No. 20-3
Presentation Time: 8:45 AM
THE DANCE OF INDIA IN THE SUPERCONTINENT CYCLES: ACCRETION, ASSEMBLY, DISPERSAL, AND REASSEMBLY OF PENINSULAR INDIA DURING THE PRECAMBRIAN, AND THE EVOLUTION OF LIFE
The Indian plate documents the geological events covering the entire recorded history of our planet from 4.2 Ga to Holocene, dancing across the mantle, endlessly morphing in shape and size, throughout the supercontinent cycle. The Indian Peninsula is a collage of five Archean nuclei, clustered into two large blocks: the southern is comprised of Dharwar, Bastar, and Singhbhum (DhaBaSi); the northern block is a composite of Aravalli and Bundelkhand (AraBun). The Dhabasi block is the older of the two. With the onset of plate tectonics around 3 Ga, younger belts and terranes accreted around the Archean nuclei in the subsequent geologic ages. These Archean cratons were dissected by three Proterozoic collision belts that fused them into the Indian Peninsula ~2 Ga. These three mobile belts, namely the Central Indian Tectonic Zone (CITZ), the Aravalli-Delhi Mobile belt (ADMB), and the Eastern Ghat Mobile Belt (EGMB) reveal the tectonic processes, the magmatism, sedimentation, metamorphism, the deformation of crustal segments, and the suturing episodes that joined the five cratons. The CITZ marks the collision zones between the Dhabasi and the Arabun cratons, the ADMB between the Aravalli and the Bundelkhand cratons, and the EGMB between the Dhabasi and the Rayner complex of Antarctica. The assembly of the Indian Peninsula as a stable continent is however short-lived in the history of supercontinent cycles, breaking once again into three blocks and dancing across the globe, until their final assembly in Pannotia. Geochronological constraints, stratigraphic correlations, and paleomagnetic pole positions suggest that the Indian Peninsula holds a key position in the assembly, dispersal, and reassembly of the several Precambrian supercontinents, namely Protochthonia (formally Vaalbara, ~3.5 – 2.8 Ga), Columbia (~1.8 – 1.3 Ga), Terra Borealis (~ 1.3 Ga – 1.2 Ga), Rodinia (~ 1.1 Ga – 7.5 Ma), and Pannotia (~633 – 573 Ma). From Pannotia on, the Indian Peninsula remained stable as a unified craton. Alongside this long lithosphere evolution, Indian Precambrian marine sediments also chronicle the rich history of biological evolution from bacteria to eukaryotes to metazoans and finally the blooming of large Ediacaran animals during Pannotia.