GEL 25 Lecture Notes - Lecture 10: Canyonlands National Park, Headward Erosion, Bending
Document Summary
Paradox sea evaporites. (1) paradox salt deposits buried by 2km of younger rock (2) weight of overlying rock cause lower density salt to flow like a thick plastic, forming broad walls of salt. Flexure of the stiff overlying rock creates nw-se oriented joint sets. (3) dissolution of the uppermost salt by groundwater leaves the overlying rock unsupported caused it to collapse. Petroglyphs and rock art demonstrate native americans who lived in the area. Underlain by paradox salt (up to 5000" thick) Drainage systems of gillies & streams cut canyons into the plateau by headward erosion. Shallow washes draining the plateau focus erosion at narrow slots near the tip of the canyon, causing the canyon to grow in a headward direction through time.
