The Ellsworth Mountains, first mapped under the leadership of Campbell Craddock, pose critical geological
enigmas, solved and unsolved. The isolation of the mountains, their abrupt structural terminations and Paleozoic
stratigraphic affinities are explained by rotation from the cratonic margin during Gondwanaland breakup. The
mechanism remains obscure. The absence of intense folding associated with the Cambro-Ordovician Ross orogeny can
be ascribed to local extension along a subducting margin. Yet tantalizing questions regarding possible Precambrian
connections to Laurentia remain, and the cause of the post-Permian Gondwanide folding is controversial.
The elevation (~5000m) is high for an early Mesozoic fold belt. Thermal uplift could have been initiated during
Jurassic-Cretaceous block rotation and Weddell Sea opening and continued into the Cenozoic. The history of glaciation
provides input for models of ice loading and unloading. Measurements of present-day uplift test these models and help
assess change in the mass of the ice sheet and hence in global sea level.
Additional Publication Details
USGS Numbered Series
The Ellsworth Mountains: critical and enduringly enigmatic