9706412 Bowring The assembly and breakup of the Late Proterozoic super continent of Rodinia is a fundamental question of late Precambrian tectonics. Because the rock record of this time interval is so limited, studies of the well exposed rocks that do exist become all the more compelling. In a broad attack of this problem, the University of New Mexico, Harvard, and MIT will work collaboratively on late Proterozoic rocks of the southwestern edge of North America. These investigators will study the geological, paleontological, and tectonic evolution of a sequence of sedimentary and volcanic rocks of Late Proterozoic age in the southwestern US. The structural, sedimentological, geochronological, paleontological, and paleomagnetic data to be collected will bear directly on the ages and sedimentary and tectonic environments of deposition of these rocks, and at the same time examine the Late Proterozoic evolution of life prior to the Cambrian diversification of animal life.