Arizona

 

Geological State Symbols Across America           Geology of the National Parks Through Pictures


Arizona State Geological Symbols
Type
Symbol
Year Established
State Gemstone
Turquoise
1974
State Fossil

Petrified Wood

(Araucarioxylon arizonicum)

1988
State Metal
Copper
2015

 

State Gemstone: Turquoise

TurquoiseTurquoise is a blue-green mineral made up of copper, aluminum, and hydrous phosphate (CuAl6(PO4)4(OH)). The name turquoise comes from the French expression for "Turkish Stone", illustrating that the early sources for European turquoise were from the Middle East. Turquoise has long been considered valuable and is one of the oldest known gemstones. It has been found in ancient Egyptian and Chinese archeological expeditions, showing that those people used turquoise as far back as 3,000 years ago. It is formed by the flowing of groundwater through copper deposits that eventually react with phosphate and aluminum minerals. Turquoise is also only found in arid (desert) environments because that is one of the few places that allows the groundwater to maintain a high enough copper concentration for long enough to interact with the other minerals. The result is a gemstone unlike traditional, gemstones like ruby or emerald, which is most commonly opaque. The opaqueness is due to the structure of turquoise, which is made up of many microcrystalline structures instead of one large mineral crystal. These microcrystals give the turquoise its appearance, either a mottled look or a smooth finish, which is due to the size of these microcrystals. It is also extremely soft and easy to carve. All of these attributes make it useful for many different purposes from jewelry to architectural adornments.

 

Spider-web TurquoiseTurquoise mines can be found all across the southwestern United States, with the largest concentration found in Arizona. As mentioned above, turquoise mines in Arizona are often associated with copper mines (many of them open-pit mines in AZ). The largest and most well known of the turquoise mines is the Bisbee Mine, near Bisbee, AZ, located adjacent to the Copper Queen copper mine. In 1880, the mine was founded as a gold, silver, and copper mine, which are often found together due to the formation of these minerals from the waters associated with subduction zone magmatism. The hydrothermal waters associated with the former subduction zone in the region circulated throughout the rocks depositing the heavy metal deposits within the bedrock. These heavy metal deposits eventually interacted with the local groundwater producing these turquoise deposits. The Bisbee Mine turquoise was discovered in the 1950's and quickly became prized for it's spider-webbing patterns throughout the turquoise stones (pictured left). Although most of the turquoise has been mined out, this has resulted in these variety of the gem to become prized collectors items. Native Americans (primarily the Anasazi and the Hohokam) mined the turquoise in Arizona for use in jewelry and for trade. Arizona is also home to one of the largest domestic turquoise mines, located in Kingman.


State Fossil: Petrified Wood (Araucarioxylon arizonicum)

Petrified WoodPetrified wood is not actual wood, however it was wood at one point. Petrified wood is a fossil that formed from pieces of wood that have been mineralized. Mineralization is a process where groundwater moves through the wood and replaces all of the wood molecules with molecules of other substances, most often silica (i.e. quartz). This means that petrified wood actually isn't wood anymore, but a fossil of the former wood.

 

The specific species of petrified wood (Araucarioxylon arizonicum) that is the Arizona state fossil is an extinct conifer (like an evergreen) that can been found throughout Arizona and New Mexico. There is a problem with the state fossil though; the original name of the species was based on three different species. This means that although one of the three was correct, two had to be renamed, resulting in several of the trees identified since the initial 1889 description were likely named incorrectly. The problem is that proper identification can only be made with thin sections and close analysis, which is not likely going to happen for a majority of the samples previously identified, at least not any time soon. Arizona is host to one of the largest assemblages of petrified wood logs, with ~20% of all the petrified wood in northeastern Arizona found in Petrified Forest National Park. The concentrations of logs in Petrified Forest was a result of a log jam that flowed down a prehistoric river. The logs where then quickly buried, which allowed the mineralization process to proceed on the logs, converting them into fossils.

 

State Metal: Copper

Native CopperCopper is an elemental metal mineral, meaning that it is entirely composed of one element; copper (Cu) in this instance. It is also the only elemental metal, besides gold, which is not naturally silver or grey. Copper is the oldest known metal to have been manipulated by humanity. The Copper Age took place after the Neolithic (Stone) Age, and lasted from ~4500 BC to ~3500 BC, overlapping with the early Bronze Age. The earliest known Middle Eastern artifact is also made of copper, a pendant dating back to 8700 BC. In the modern day, copper is the third most consumed industrial metal in the world. Mining of copper in the US began with high grade ore deposits found in Arizona and Michigan in the late 1800's, however newer processes that were able to filter the copper out of low-grade deposits made excavating low-grade ores more economical, leading to more abundant uses of strip and open-pit mining for the recovery of copper. These processes enabled the US to become one of the leading producers of copper in the world.

 

Arizona Mineral Map

In the late 1600's, Spanish explorers traveled the west looking for metallic deposits, specifically gold and silver. The association of these metals with copper enabled them to discover numerous copper deposits as well, even though it was not their primary focus. Eventually, the modern age of mining in Arizona was born in 1854 with the creation of the Arizona Mining and Trading Company in Ajo, AZ. Mining for copper was initially restricted to deep mine tunnels of fairly high quality ore. However, the success of the open-pit Bingham Mine in Utah illustrated that open-pit mining and new processing methods for low-grade copper ore worked well and Arizona began using similar processes, increasing their copper yield significantly. Currently, copper is the most valuable metallic commodity in Arizona, followed by gold, silver, molybdenum, and lead. In 2017, the US produced 1.27 million tons of copper with 68% of that coming from Arizona. There are currently over 3,000 Arizona locations that have copper listed as a commodity. These metallic deposits form a northwest to southeast band across the state (as seen on the map to the left). Along this band, most of the copper deposits are found within southeastern portion of the state (red on the map). These deposits are found mostly in granitic rocks that intruded within the region 70 to 55 millions years ago.

 

References

https://statesymbolsusa.org/states/united-states/arizona

https://www.gia.edu/turquoise

http://www.azsos.gov/public_services/kids/kids_state_symbols.htm

http://en.wikipedia.org/wiki/Turquoise

http://www.turquoise-museum.com/arizonaturquoisemines.htm

http://www.turquoisemines.com/bisbee-turquoise-mine/

https://www.durangosilver.com/spiderweb-turquoise-cabochons.html
http://minerals.usgs.gov/minerals/pubs/commodity/gemstones/sp14-95/turquoise.html

http://indianvillage.com/arizonaturquoisemines.htm

http://www.traderoots.com/Turquoise_About.html#Introduction

http://www.carionmineraux.com/mineraux_avril_09.htm  

http://en.wikipedia.org/wiki/Araucarioxylon_arizonicum  

http://waynesword.palomar.edu/pfnp.htm 

http://www.nps.gov/pefo/index.htm

http://factsanddetails.com/world/cat56/sub362/item1495.html

https://www.livescience.com/29377-copper.html

https://minerals.usgs.gov/minerals/pubs/commodity/copper/mcs-2018-coppe.pdf

http://repository.azgs.az.gov/sites/default/files/dlio/files/nid1609/ofr92-10copperoxideresources.pdf


Geology of Arizona's National Parks

Through Pictures

(at least the one's I have been to)

 

Casa Grande Ruins National Monument

Visited in 2016

Although Casa Grande Ruins is mainly an archaeology park, there is geology everywhere. Even if sometimes it is just a pretty picture of the landscape. For Casa Grande Ruins we learn how settlers in the land used the land, even as inhospitable as it may seem, to their advantage.

Casa Grande NM

 My entrance sign picture

 

Casa Grande NM

The Casa Grande (big house), which is being protected from the elements via a giant tent structure. As a building which was built over 650 years ago, it's looking pretty good. Some other structures and the base of walls from structures long ago are in the foreground.

 

Casa Grande NM

As can be read on the sign, the ancient Sonoran people used caliche (pronounced ka-lee-chee), which is a calcium carbonate rich desert soil. The caliche was then collected, then mixed with water and formed into the walls while wet. Once dried, the walls have lasted centuries.

 

Casa Grande NM

A close up view of the front of the house. You can clearly see the difference between the fixed areas (along the base and around the door) and the original areas.

 

Casa Grande NM

The back side of Casa Grande

 

Casa Grande NM

Looking up into Casa Grande. 

 

Casa Grande NM

Several of the outlying buildings are partially intact as well. The is one of the structures to the south of Casa Grande. 

 

Casa Grande NM

 Looking north towards Casa Grande.

 

Casa Grande NM

 A view of the Sonoran Desert with a Sonoran Desert People's "ball pit" located in the foreground. As you can see, there is not much in this desert environment. Even cacti are not that prevalent. 

 

Casa Grande NM

View of the Casa Grande with one of the old signs and a saguaro cactus. 


Glen Canyon National Recreation Area

Visited in 2009

 

Glen Canyon NRA

For all of the pictures from Glen Canyon National Recreation Area be sure to head over to the:

Utah Page


Grand Canyon National Park

Visited in 2011

 

Grand Canyon National Park

The entrance sign.

 

Grand Canyon National Park

This is our first view of the canyon. We went during the middle of March. Not a good time to go apparently.

 

Grand Canyon National Park

But it did eventually clear up. This is a similar location as the previous picture on a subsequent day.

 

Grand Canyon National Park

Some elk by our hotel room. 

 

Grand Canyon National Park

View off into the canyon. The canyon began to be formed due to plate tectonics. There used to be a subduction zone off the western coast of California (where the San Andreas Fault is now). The plate that was subducted, the Farallon Plate, was forced down underneath North America. This plate was hot and therefore force the North American Plate upwards. The upward push of the plate was counteracted by the Colorado River eroding down through the plate. The upward motion of the plate allowed the river to erode downward faster and deeper than it otherwise would have.

 

Grand Canyon National Park

The rock units that were eroded through range in age from fairly recent to over a billion years old. The types of rocks are limestones, sandstones, shales, as well as several metamorphic and igneous rocks. The result is a huge range of bright colors represented in the canyon.

 

Grand Canyon National Park

Here I am trying to get a vertical view of the canyon.

 

Grand Canyon National Park

The cloud formations across the surface here made the landscape really look pretty.

 

Grand Canyon National Park

Here is a panoramic view of the canyon.

 

Grand Canyon National Park

Another panoramic view.

 

Grand Canyon National Park

Along the rim they have these markers designating the passage of geologic time. I walked all the way back to the beginning to get the first one.       

 

Grand Canyon National Park

A cool train station within the park.


Hohokam Pima National Monument

This is a very bizarre "park" just south of Phoenix, AZ. When you try to find out any official information on the park, the park website either doesn't exist or it simply says "The area is not open to the public". When I asked at the nearby Casa Grande Ruins NM about this park they told me it wasn't a real park at all and never was formed into a park. However the park is on the NPS website, and on all maps and fliers that list all the parks officially published by the NPS. From what I can find out, this park is officially on a Native American Reservation and it is not open to the public. The park was an ancient ruin, similar to Casa Grande Ruins, however instead of fully excavating them and displaying them, they were buried again after excavation to preserve them. So, even if you could gain access to the "park" there wouldn't be anything to see anyway.

 

Well, long story short, the official park property crosses over Interstate 10, and it was in the official part of the "park", where I stopped and grabbed a panoramic shot.

Hohokam Pima NM

Photo looking west over the rest of Hohokam Pima National Monument during sunset. 


Sunset Crater Volcano National Monument

Visited in 2011

 

Sunset Crater Volcano NM

View of the entrance sign with the volcano in the background.

 

Sunset Crater Volcano NM

The Sunset Crater Volcano is a volcano that last erupted about 1,000 years ago. It is a type of volcano known as a cinder cone, meaning that its eruptive material is small darkly colored rocks that pile up around the central vent. These rocks are typically a type of rock known as scoria, a vesicular (has lots of air holes in it), mafic (dark), volcanic rock. Since the last eruption was within the last 10,000 years, this volcano is still considered active by volcanologists.

 

Sunset Crater Volcano NM

Along with the cinder cone, there are also lots of lava flows within the park. Here you can see a lava flow that still looks as fresh as if it were a few years old. Since the desert environment does not get much rain, the volcanic rocks have a tendency to take a long time to break down, leaving these features for thousands of years.

 

Sunset Crater Volcano NM

Sunset Crater Volcano is part of a fissure eruption, which is a long crack in the ground that erupts like a volcano. Here the fissure runs along the left part of the photo ending at Sunset Crater Volcano in the middle of the photo.

 

Sunset Crater Volcano NM

Sunset Crater Volcano isn't the only volcano within the area or even within the park. There are lots of volcanos in this part of Arizona, mostly due to the plate tectonics of the area (as described in the Grand Canyon NP section above). The thinning of the crust due to the uplift of the plate causes weak spots in the crust where volcanic material can easily break through.


Walnut Canyon National Monument

Visited in 2011

 

Walnut Canyon National Monument

Walnut Canyon is a archaeological site located within a geological site. The canyon itself is made up of several Colorado Plateau rock units that were impacted, like several other National Parks in the area, by the uplift of the Colorado Plateau. The canyon is capped with the Permian Kaibab Formation limestone, forming a layer resistant to erosion. The shelters created within the rocks are located within a shale and siltstone layer of the Kaibab Formation beneath this limestone roof.

 

Walnut Canyon National Monument

Below the Kaibab Formation is the Coconino Sandstone and Toroweap Formation. These rock units are often difficult to differentiate from each other so they tend to blend together within the park.

 

Walnut Canyon National Monument

Here you can see a view of the canyon with the alternating hard and soft rock formation.

 

Walnut Canyon National Monument

View of the cliff dwellings built into the carved out section of the rocks.

 

Walnut Canyon National Monument

Some more cliff dwellings.

 

Walnut Canyon National Monument

And more cliff dwellings with a more complete wall located on the other side of the creek meander.

 

Walnut Canyon National Monument

Following the trail around the houses, the trail goes back up the canyon.

 

Walnut Canyon National Monument

Here is the Coconino Sandstone which underlies the Kaibab Formation. The cross-bedding is characteristic of the unit and illustrates the former desert dune history of the rock units.

 

Walnut Canyon National Monument

A view of Walnut Creek, which carved out the canyon through the rock units. The cliff dwellings are located within the meander on the right side of the photo.


Wupatki National Monument

Visited in 2011

 

Wupatki National Monument

The obligatory entrance sign. The park is located on the edge of the San Francisco Volcanic field and the Painted Desert. This means that ancient people within the area likely had to contend with volcanic eruptions, as seen at the nearby Sunset Crater above, as well as the arid desert environment.

 

Wupatki National Monument

Here is a distant view of the Wupatki pueblo. Although mostly an archaeological park, there is tons of geology to be seen from all of the rock formations to the desert climate itself. The pueblos are built on top of and out of the Moenkopi Formation. These are sandstones, siltstones, and shales from a Triassic tidal environment. This means that it was pretty close to the shoreline but also contained floodplain deposits.

 

Wupatki National Monument

  Here is a closer view of the Wupatki Pueblo. Because of all of the mud content (silt and clay) within the Moenkopi, the rocks have a strong brown and red color to them.

 

Wupatki National Monument

Here is another of the pueblos, the Citadel Pueblo.

 

Wupatki National Monument

Closer, a little more abstract view of the Citadel Pueblo. 

 

Wupatki National Monument

Close up view of the Moenkopi bricks.