CONVECTIVE REMOVAL OF LITHOSPHERE BENEATH MOUNTAIN BELTS - THERMAL AND MECHANICAL CONSEQUENCES
Shortening and thickening of continental lithosphere cause an increase in surface elevation, a decrease in the thermal gradient and, unless the crust is initially quite thick, a decrease in potential energy with respect to a mid-ocean-ridge lithospheric column. Continental convergence could therefor...
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| Format: | Journal article |
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1994
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| Summary: | Shortening and thickening of continental lithosphere cause an increase in surface elevation, a decrease in the thermal gradient and, unless the crust is initially quite thick, a decrease in potential energy with respect to a mid-ocean-ridge lithospheric column. Continental convergence could therefore be self-sustaining. The lower part of the lithosphere is probably removed intermittently by convection. Convective removal of the lithospheric root below regions of continental convergence will cause a rapid increase in surface elevation and potential energy and create a step in the geotherm. The large excess in potential energy with respect to its surroundings may result in indefinite extension of the continental column. Extension of lithosphere immediately following convective removal of the root will decrease the thermal time constant for decay of the step in the geotherm, allowing a transient heating event to affect the crust. -from Authors |
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