Search results
Results from the WOW.Com Content Network
It has a Mohs hardness of 7 and a specific gravity of 3.3 to 3.4. Crystals show pleochroism from red to blue to violet. Dumortierite quartz is blue colored quartz containing abundant dumortierite inclusions.
Petrified Forest National Park is a national park of the United States in Navajo and Apache counties in northeastern Arizona.Named for its large deposits of petrified wood, the park covers about 346 square miles (900 square kilometers), encompassing semi-desert shrub steppe as well as highly eroded and colorful badlands.
The Aztec Sandstone is made up of two units. The lower resistant sandstone unit (100 metres (330 ft) thick) is tan to off-white in outcrops but pinkish in fresh exposures. Cross-bedded lenses can easily be observed. Frosted and pitted quartz grains well-cemented by silica are described by Evans in 1958 and 1971.
The name of the park gives it away: Most of the fossils you'll see at Petrified Forest are of exquisite petrified wood from the Triassic period over 200 million years ago.
Glaciation of the southern hemisphere raised and lowered sea levels in Arizona, creating the ledge and slope topography common in the Grand Canyon, Sedona and Monument Valley, with alternating layers of siltstone, limestone, sandstone, dolomite and shale. The Kaibab Limestone is a famous formation from this time, covering much of northern ...
Caliche fossil forest on San Miguel Island, California. Caliche (/ k ə ˈ l iː tʃ iː /) (unrelated to the street-slang "Caliche" spoken in El Salvador) is a soil accumulation of soluble calcium carbonate at depth, where it precipitates and binds other materials—such as gravel, sand, clay, and silt.
Almost 12 years ago, a pilot flying a small plane over the desert in Arizona spotted something she would never forget. Pez Owen told NPR that when she noticed white crosses on the ground, she and ...
Araucarioxylon arizonicum (alternatively Agathoxylon arizonicum) is an extinct species of conifer that is the state fossil of Arizona. [1] The species is known from massive tree trunks that weather out of the Chinle Formation in desert badlands of northern Arizona and adjacent New Mexico, most notably in the 378.51 square kilometres (93,530 acres) Petrified Forest National Park. [2]