PRECAMBRIAN-CAMBRIAN BOUNDARY MICROBIOTA FROM THE CHERT PHOSPHORITE MEMBER OF TAL FORMATION IN THE KORGAI SYNCLINE, LESSER HIMALAYA, INDIA

Abundant and well preserved organic walled microfossils are recorded f rom the Chert-Phosphorite Member of the Tal Formation, in the Korgai S yncline, Lesser Himalaya, Two principal categories of microfossils inc luding spheromorphic acritarch and small acanthomorphic acritarchs are present in the assemblage. Interesting among these two categories are Leiospheridea sp., Micrhystridium regulare, M. sp. A, M. sp. B, M. sp . C, M, sp. D and Veryhachium sp. The appearance of large Micrhystridi um population together with small shelly fauna has been used as a crit erion to demarcate the Precambrian-Cambrian boundary in China(1) where these microfossils have been discovered from the black chert in the p hosphatic rocks of the lowest Kuanchuanpu Member in Ningqiang of south ern Shaanxi.