U-Pb ages of the Himalayan foreland basin Northeast India: Implications for the India-Asia collision

Summary

Syn- and post-collision between Indian and Eurasian plates, several peripheral foreland basins were formed that accommodate the detritus from the adjoining regions. The geochronological study is a precise tool for understanding the provenance in this regards several studies have been carried out in the central and western Himalayan foreland basin, while very little in the eastern Himalaya. The present study carried out in the Siang river valley, eastern Himalaya by means of detrital zircon U-Pb geochronology. The Late Paleocene to Early Eocene Lower Yinkiong Formation and Early to Mid-Eocene Upper Yinkiong Formation, deposited in the distal foredeep and foredeep deopzone of the foreland basin respectively. The detrital ages of the Lower Yinkiong Formation are dominantly older than late Paleozoic, resembling the cratonic and early Himalayan Thrust Belt (HTB) affinity. However, there is the presence of Cenozoic age grains in Upper Yinkiong Formation indicate the HFB source and possible the granitic body within the Asian plate. This shifting of source regions signifies the India-Asia collision in the Eastern Himalaya began before or immediately after the Early Eocene (~56-50 Ma).

• Yinkiong Formation
• Siang window
• Eastern Himalaya
• India-Asia collision
• Provenance Analysis