Abstract
A model for continental uplift at a convergent margin (Damon, 1979) is further developed. The model assumes the necessity of isostatic compensation of the subducted lithospheric plate. It predicts a continental declivity that reaches its maximum uplift and extent at the time of trench-spreading center collision. As a result of the passage of the subducted plate eastward the region of maximum uplift increases and migrates eastward behind the eastward migrating declivity. The “gang plank” from the Front Range to the Mississippi River is the most obvious modern expression of the continental declivity whereas the Great Basin is an expression of the area of maximum uplift lowered somewhat by extension and crustal thinning. Compensation takes place by transfer of asthenosphere to the base of continental lithosphere. At the time of trench-spreading center collision a pressure gradient shunts the asthenospheric current from the quenched spreading center to the channel between the continental lithosphere and the subducted plate. Sinking of the subducted plate causes upwelling of asthenosphere feeding the laminar flow between the two plates. The model is in accord with the physiography of North America and the geologic record.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call