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| Tower Point Ruin was built overlooing the intersection of two tributary canyons of Little Ruins Canyon. Over time, gradual stream erosion and gravity-induced mass wasting undercut the cliffs, causing large blocks of the cap-rock sandstone to tumble into the canyon. Some of the surfaces of the blocks and cliff surfaces preserve dark streaks of desert varnish. Desert varnish forms where water from precipitation (rain or snow) dissolves minerals from the host rock (the sandstone), then trickles down and evaporates on the rock surface and leaves a trace of manganese and iron oxide minerals and salts. Ancient carvings (pictographs) in the desert varnish slowly heal, showing that desert varnish layers build up slowly over hundreds or even thousands of years. |
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