Hobbies And Interests
Volcanic Rocks
The southeastern edge of the Sonoran Desert, in the present day Sierra Madre Occidental region of Mexico, is coated in volcanic rock that dates back 30 million years. These old rock formations are exposed in the pine forested section of the Barranca del Cobre, or Copper Canyon area, of Sonora-Chihuahua. Over time, these volcanoes collapsed, leaving behind circular basins called calderas which can still be seen in the Superstition Mountains today. Most valleys within the Sonoran Desert today are filled with 5,000+ feet of gravel, sand and clay, the result of the volcanic activity in the region 8 million years previously.
Granite and Fossils
An abundance of granite rock lies within the Sonoran Desert. The granite rocks were formed when the earth in that area pulled apart. Massive granite rock structures formed in areas ten miles in width along the fault lines in the Sonoran Desert and the oldest granite rocks are 1800 to 1400 million years old. Rocks dating 1200 million years old have been found to contain mushroom- shaped colonies of algae.
Younger rocks (about 200 million years) contain fossils of shark teeth, clams, horsetails, lizards and the ancestors of rhinos, camels, mastodons, lions and giant beavers. Granite rocks in the region today are shaped into alluvial fans, spires and irregular columns. Large boulders as well as conical granite domes with structures akin to onion peels can be spotted along the high ridges on the west side of the Santa Catalina Mountains.
Sonoran Desert Gems
While the Sonoran desert is rich in plant, tree and animal life, containing species like the Arizona ask, Fremont cottonwood, numerous cacti and all many of desert animal life, it is also rich with rock gems like translucent gold agate and quartz agate. Many of the gemstones found in the Sonoran Desert are on display at the Sonoran Desert Museum in Arizona including opal and chalcedony which are prevalent in volcanic rock, silver and tourmaline which is present in metamorphosed limestone.
Sonoran Desert Minerals
In addition to gems, a variety of minerals in rock form are found throughout the Sonoran Desert. These minerals are plentiful and diverse and include azurite, blue calamine, cprite, Nevada opal, quartz, quicksilver and turquoise. Along with gemstones, minerals are on display at the Sonoran Desert Museum, which also includes a zoo and trails as well as a plethora of information about the desert.