Dean M. Chriss
Photography
Megabreccia Mosaic
(Click image to enlarge)
This large mosaic rock forms part of a canyon wall. In geology
formations like this are called megabreccia. There are several
types of megabreccia that are formed in different ways giving
each a different appearance. In this case the darker fragments
were formed by stretching of older Cambrian era (541-485 million
years ago) rocks due to folding that occurred during the middle
to late Mesosoic era (250 to 65 million years ago). Gaps that
developed between the fragments were filled with the lighter
colored rock, called travertine. Travertine is a form of
calcium carbonate leached from adjacent layers of limestone
and dolomite.