9805461 Ruppel The volcanoes of Late Proterozoic to middle mesozoic age along the circum-Atlantic produced one of the earth's most a really extensive large mafic volcanic occurrences. Recent work has indicated that much of this mafic magmatism was emplaced over only a few million years. This collaborative project will focus on an incompletely studied portion of the mafic volcanic province, and will attempt to test the timing constraints and to apply the results to various models for the driving forces for the Pangean rifting event that produced the present day Atlantic Ocean.