These sediments were deposited at a passive margin that likely developed during the rifting of North America from the East Antarctic Shield .
Were subsequently deformed and metamorphosed at a low - to medium - grade and intruded by syn - and post-tectonic granitoids .
These sediments were deposited at a passive margin that likely developed during the rifting of North America from the East Antarctic Shield , and were subsequently deformed and metamorphosed at a low - to medium - grade and intruded by syn - and post-tectonic granitoids .