Sierra Blanca Spring Geology
Above, a view of Sierra Blanca Spring from a point just above it, showing rocks of the Cascabel Formation that have been impregnated and more intensely lithified by the calcium carbonate associated with spring waters. Below, note how sharply these beds stand out in appearance from the CF rocks that lie below (and above) them: (Click on each image to enlarge it.)
Below, two views of the upper lip from the right-bank side, at left, and the left-bank side, at right, provide different views of the structure of this near-vertical bed. (Note the reddish matrix mingled with the white crystals in the photo at left. (Click on each image to enlarge it.)
Veins of calcite crystals running through layers of Cascabel Formation conglomerate appear very frequently in this area. Just above the Spring in Sierra Blanca Spring Wash, one sees many such veins crosscutting and replacing the dark-reddish rock, as photographed below left, in July 2004. And in the hills far above the Spring one finds outcrops of almost vertically tilted, intensely carbonate-impregnated rocks of the Cascabel Formation, like the one at right, photographed during October of 2002. (Click on each image to enlarge it.)
Below, the heart of Sierra Blanca Spring, the pool, which is overhung by a lower lip of calcite rocks and calcium carbonate ("caliche") deposits. The image at left was taken in February of 1999, that in the middle and on the right, in July 2004. (Click on each image to enlarge it.) You can see the drip rings in the left-hand image, while the other two show the rocks more clearly.