Abstract This award supports a project to test the recent hypothesis that Laurentia (the cratonic part of present-day North America) was adjacent to the East Antarctic craton during late Proterozoic time and was therefore a part of Gondwana. The hypothesized geographic disposition of these continental masses has far-reaching implications for the assembly, evolution, and breakup of Gondwana. This hypothesis, however, has not yet been substantially tested. If Laurentia did breakout of Gondwana from a position adjacent to Antarctica, rift-related sediments should record this event and contain detritus, including detrital zircon, derived from the rifting continent. Late Proterozoic metasedimentary rocks exposed throughout the Transantarctic Mountains (including the La Gorce, Duncan, Goldie, and Cobham Formations, and the Skelton and Koettlitz Groups) are the most-likely candidates for such rocks. This project will produce a geochronometric inventory of detrital zircons from samples of these units distributed along the length of the Transantarctic Mountains. The geochronometric data will provide a useful test of the hypothesis and will complement on-going detrital zircon studies of other Proterozoic rocks in the Transantarctic Range.
