This project concentrates on field investigations of five crucial localities within the Cordilleran region of the United States and Canada. It will provide meaningful data on the evolution of late Triassic reefs and reeflike carbonate rocks within a number of displaced terranes accreted to western North America. Utilizing the dual approach of microfacies analysis and detailed paleontological study of calcareous algae and diverse benthic faunas of foraminifers, sponges, corals, molluscs and echinoids, the research will test ideas about the dispersal of the biota and the movement of accretional terranes in Alaska, the Canadian Northwest, and Oregon. The proposed project will build upon a foundation of prior research on Upper Triassic faunas and carbonate rocks of central Peru as well as recent reef discoveries at localities in Idaho and northeastern Oregon. The project will benefit from collaboration with alpine workers of Europe, pooling their knowledge to bring current understanding of the North American Triassic to levels approaching those of well-known counterparts of Europe. The formulation of a viable model for the dispersal of the biota in light of terrane theory and reef evolution, along with integration of data acquired from other regions of the world, will permit a general synthesis for global Triassic paleogeography, allowing the type of detailed resolution not currently available in either reef studies or terrane analyses in North America.