
Sinuous, water-sculpted curves of Mosaic Canyon marble. Photo by Marli Miller.
|
The entrance to Mosaic Canyon appears deceptively ordinary, but just
a 1/4 mile walk up the canyon narrows dramatically to a deep slot cut
into the face of Tucki Mountain. Smooth, polished marble walls
enclose the trail as it follows the canyon's sinuous curves. Following
faults
The canyon follows faults that formed when the rocky
crust of the Death Valley region began stretching just a few million
years ago. Running water scoured away at the fault-weakened
rock, gradually carving this remarkable canyon.
Periodic flash floods carry rocky
debris (sediment) eroded
from Mosaic Canyon and the surrounding hillsides toward
the valley below. At the canyon mouth water spreads out and deposits
its sediment load,
gradually building up a large wedge-shaped alluvial
fan that
extends down toward Stovepipe Wells.

A hiker meanders through Mosaic Canyon marble. Photo by M. Moreno, USGS.
|
Making marble
Mosaic Canyon's polished marble walls are carved from
the Noonday Dolomite and
other Precambrian carbonate rocks.
These rock formation began as limestone deposited
during Late Precambrian (about 850-700 million years
ago) when the area was covered by a warm sea. Later
addition of magnesium changed the limestone,
a rock made of calcium carbonate, to dolomite, a calcium-magnesium
carbonate.
The dolomite was later deeply buried by younger sediment.
Far below the surface, high pressure and temperature altered the dolomite
into the metamorphic rock, marble.

A close-up look at the marble walls of Mosaic Canyon reveals intricately folded layers.
|
The relatively recent uplift of Death Valley's mountian ranges and subsequent
erosion have exposed these metamorphic rocks.
Mosaic Canyon was named for
a rock formation known as the Mosaic Breccia. Breccia is
the Italian word meaning fragments. This formation
is composed of angular fragments of many different kinds of parent rock,
and it can be seen on
the floor of the canyon just south of the parking area. |