Triassic sediments in Vietnam are represented mainly by marine strata, with the exception of some areas where part of the section is characterized by continental or volcanogenic-sedimentary formations.
The Nori-Rhat sediments of N.-W. Vietnam, which were assigned by J. Depra to the marine Rhat Formation with greasy coal, and then by J. Fromage to strata with Myophorianapengensis, by A. E. Dovzhikov to the Suoi Bang Formation, by the author and by Nguyen Vinh to the Suoi Bang Formation, are widespread in many areas ...