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Authors
Affiliations
1 Wadia Institute of Himalayan Geology, Dehra Dun 248001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 26, No 2 (1985), Pagination: 111-117
Abstract
Algal pisolites, oncoids, columnar stromatolites and columnar layered stromatolites have been recorded from cherty dolomitic limestones from Upper Krol and Lower Tal formations. The algal mat facies show bird's eye structures and irregular fenestral fabric suggesting an intertidal supratidal environment of deposition for Upper Krol (D and E) Formation of Garhwal syncline. The basal Lower Tal Formation of Mussoorie syncline also represents a complex algal oncoidal-stromatolitic (protected tidal flat/lagoonal) facies with restricted circulation. The association of phosphorite with stromatolites and oncoids proves the phosphorite to be deposited in a shallow water environment. The presence of pyrite and associated black shales indicate an erobic condition.