TAPEATS SANDSTONE
Cambrian Period, 515 Million Years Old, 300 Feet Thick
A brown, distinctly layered cliff
The Tapeats is a massive cliff-forming unit of brown sandstone. Much of
the sand is very coarse-grained, often pea-sized or larger, and some grains are
beautifully colored--my students call this the M&M conglomerate. The Tapeats
Sandstone represents near-shore beach and sand bar deposits.
The base of the Tapeats contains a conglomerate member (part of
the Tapeats), called the Hotauta Conglomerate. This was a pebble beach formed as
the Tonto Sea encroached and tore up the Vishnu, so the Hotauta contains schist
and granite pebbles.
Here is a closer view of the Tapeats Sandstone as seen from below.