The Geology P.A.G.E.: Geological State Symbols Across America

The next state up for the Geological State Symbols Across America is:

California

You can find any of the other states geological symbols on my website here: Dinojim.com (being updated as I go along this year).

Year Established
State Rock: Serpentine 1965
State Mineral: Gold 1965
State Gemstone: Benitoite 1985
State Fossil: Smilodon fatalis (saber-toothed cat) 1973
State Dinosaur: Augustynolophus morrisi 2017

I also have several Geology of the National Parks Through Pictures that I have done for California previously. These include:

Death Valley National Park
Fort Point National Historic Site
Golden Gate National Recreation Area
Joshua Tree National Park
Lassen Volcanic National Park

Mojave National Preserve
Muir Woods National Monument

State Rock: Serpentine

CHAPTER 89

An act to add Sections 4-25.1 and 4-25.2 to the Government Code. relating to state emblems.

The people of the State of California do enact as follows:
SEC. 2. Section 425.2 is added to the Government Code, to read:
425.2. Serpentine is the official State Rock and lithologic emblem.

A 2012 carving by Jonah Akpalialuk de Pangnirtung Nunavut of a walrus in serpentine. Image courtesy of Hugh.macisaac CC BY-SA 3.0.

Serpentine is a green to black, fibrous and platy, metamorphic rock. It was metamorphosed from the ultramafic (dark green minerals like olivene) rock peridotite. It was named for the serpent skin-like pattern formed by the multitude of greens throughout the rock. The original parent rock, peridotite, was deposited in the ocean, below the basalt and other crustal rocks. The high heat, water, and high pressure converted the peridotite into serpentine. Serpentine itself is often composed of three main minerals, chrysotile (Mg3Si2O5(OH)4, a fibrous mineral, often found in the form asbestos), lizardite (Mg3(Si2O5)(OH)4), and antigorite ((Mg,Fe)3Si2O5(OH)4), among others. Most of the minerals within the serpentine group have very similar chemical formulas, being generally magnesium-iron silicates. Even though they have very similar chemistries, it is their different structures that identify them as unique minerals (like a diamond and graphite both are just composed of carbon). Serpentine has a variety of uses including ornamental stone, due to its distinctive green color and soft texture. The minerals range in hardness from 3 to 6, making them easy to carve but fairly resistance to weathering. Serpentine is also known for its ability to resist heat, making it a valuable insulator and the primary reason it became into such widespread uses. Asbestos, made from the serpentine mineral chrysotile, was once a major industrial mineral, however the discovery of diseases associated with inhaling powdered asbestos has significantly impacted the importance of this mineral.

Outcrop of serpentine from the Paradise Serpentine Barrens by Wildflower Hikes.

Serpentine has an important place in the geological history of California. California was formed by the accretion of various islands and oceanic material as the North American plate moved westward and the subduction zone along the west coast of North America (where the westward lying Farallon Plate went underneath North America) allowed material to be "scraped" off of the subducting plate. These landforms that were scraped off the subducting plate were called "accretionary provinces" and they contained large pockets of serpentine within them. These accretionary provinces provided California with an abundance of valuable serpentine minerals including chrysotile, as well as chromite, magnesite, and cinnabar. For this reason, as well as its soft nature making it an easy stone to polish and use as an ornamental rock, it was designated as California's state rock. The ever-presence of serpentine within California is so strong that there are several forms of plant life that have evolved and thrive within the serpentine rich soil. Typically these soils would be toxic to most plant life due to the high amounts of magnesium and iron within the soil, but as Ian Malcolm said, life finds a way. Currently there are several species of plants that adapted to these types of soils that are distinctive enough from the neighboring soils that scientists can identify the soil just by looking at the plants, termed "serpentine plants". The formation and accretion of serpentine also is an indicator of other minerals within the region. Just the presence of serpentine could indicate other heavy metals such as gold, silver, and copper, since all of these minerals are related to the metamorphism and hythrothermal activity that can form serpentine. Unfortunately, due to the strong association of serpentine with asbestos, there has been recent urges to change or remove the state rock. Having the state rock associated with cancer is not something many lawmakers agree with. Scientists contend though, that asbestos within its natural state is harmless. Only when powdered, can asbestos become a carcinogen. Currently it is unsure whether the rock will be removed as the state rock.

State Mineral: Gold

CHAPTER 89
An act to add Sections 4-25.1 and 4-25.2 to the Government Code. relating to state emblems.

The people of the State of California do enact as follows:
SECTION 1. Section 423.1 is added to the Government Code, to read:
425.1. Native gold is the official State Mineral and mineralogic emblem.

Gold in quartz from Hangtown, Placerville, El Dorado County, California. Photo courtesy of johnbetts-fineminerals.com.

The chemical symbol for gold is Au, and gold is one of the unique minerals that, in its pure form, is composed entirely of one element. It has a hardness of 2.5 to 3 on the Mohs hardness scale meaning that it actually is very soft (your fingernail is 2.5). For this reason most gold jewelry is mixed with another metal to prevent scratching and bending easily. The karat rating of the gold represents it's purity, where 24 karat is 99.9% pure, 22 karat 91.7%, 18 karat 75%, and so on. Gold naturally does not corrode or tarnish, so even when it is mixed with other metals it usually has a resistance to tarnishing, enhancing its value for jewelry. When gold is found in place, the highest grade of gold is often found in association with quartz veins. Currently gold is considered one of the most valuable metals on Earth, being used as the standard for most money (gold standard). Gold is often formed initially in relation to volcanic regions, where fluids associated with volcanoes carry the heavy metals up towards the surface and deposit them in rocks. These are found in areas of current or former subduction zones, places where two plates came together forcing one place down and melting it, while the other plate is forced upwards into mountains. Afterwards, erosion will take the gold out of the mountains and carry them down stream. However, since gold is so dense it does not travel easily down rivers and will often settle to the bottom of the river within the rocks and mud within the river sediment. These gold deposits are known as placer deposits and are the primary place where gold panners find gold. They can then use the locations of these placer deposits to backtrack to the original sources of the gold within the streams.

Location of gold deposits found across the state of California. Map from Weiner and Suchanek, 2008.

Gold was initially discovered in California in 1848 at Sutter's Mill in Coloma. This discovery eventually brought on the Gold Rush of 49' (the name of the 49ers are based on this gold rush as well). The Gold Rush increased the number of people in California from pre-1849 to post-1849 100 times (going from less than 1,000 to over 100,000). The discovery of gold and sudden influx of people to California, caused it to have statehood decades before most of the other western states. Overall, ~$2,000,000,000 worth of gold was extracted from the state during this time period. The current slogan for California, "The Golden State", is due to this foundation on gold. California's gold mines (current and historic) cover the entire state and can be found from the very southern border all the way to the northern border, with almost every county having at least one (as seen in the map to the left). The formation of this gold is directly tied to the former subduction zone that was located off of the western coast of California (the now San Andreas strike-slip fault). As was mentioned above in the Serpentine section, California was formed from the accretionary provinces from this subduction zone that lastest around 200 million years, and is still continuing today along the coast of Oregon and Washington. As the subduction zone forces one plate downwards, that downward plate begins to melt, forming volcanoes. Most of the volcanoes located within California today (both active and extinct) are due to this subduction zone. Along with the volcanism, is a large amount of hydrothermal fluids working their way through the rock. These hydrothermal fluids carry large amounts of heavy metals including gold, silver, copper, and many others from deep down in the crust up towards the surface. As these fluids work their way through the overriding plate, they deposit these heavy metals, creating the gold deposits that are so well known in California. As these deposits then start to erode from the mountains, the high specific gravity of gold (high density) and its resistance to oxidizing (tarnishing) causes the gold to concentrate on the bottom of river beds forming what are called placer deposits. It is from these deposits that people find gold while they perform the famous "wild west" practice of panning for gold.

State Gemstone: Benitoite

CHAPTER 1365
An act to add Section 425.3 to the Government Code, relating to the state gemstone.

The people of the State of California do enact as follows:
SECTION l. Section 425.3 is added to the Government Code, to read:
425.3. Benitoite is the official state gemstone.

Benitoite from Benitoite Gem Mines, San Benito County, California. Photo courtesy of johnbetts-fineminerals.com.

Benitoite is an extremely rare mineral where the only gem quality stones are found in California. It is often found as a blue to dark blue mineral but can be purple, pink, white, and colorless that also fluoresces blue under ultraviolet light. Benitoite is a barium titanium silicate (BaTiSi3O9) that often forms pyramidal crystals, although the crystals are usually 5 cm or less in size. It was initially found near the headwaters of the San Benito River, in San Benito County, California, and was named for its discovery location. When benitoite was originally discovered it was thought to be another variety of sapphire. However, further analysis by some jewelers ruled out the gem as a sapphire, mainly due to the hardness of the mineral. A sapphire has a hardness of 9 on Moh's Hardness Scale, while benitoite has a must softer hardness of 6-6.5. In 1907, George D. Louderback, identified and named the unique and very rare mineral. Primarily benitoite is known as a collector's item with a small amount of samples being used to align and adjust electron microprobe beams. Benitoite is found within natrolite veins that are interlayered with serpentine. Benitoite forms from the hydrothermal altering of the serpentinite, a primary mineral found within the state rock, serpentine.

Map of the location of the Benoite Gem Mine. The map is courtesy of Laurs et al., 1997 and collectorsedge.com.

Currently, gem quality benitoite is only known to occur in the one location that it was originally discovered in, known usually at the Benitoite Mine (as mapped above). Upon discovery of the gems, they were found within another mineral, natrolite. The natrolite was a blessing and a curse. Natrolite was great because it protected the crystals from being damaged, however when trying to remove the benitoite crystals from the natrolite many crystals were damaged in the process. Modern methods of dissolving the natrolite though has enabled a much larger number or gem quality stones to be removed from the mine. However rare and valuable the gem is, collectors and rock hounds have the unique chance to collect their own specimens of benitoite by going to the California State Gem Mine. Where, for a fee, you can try and find some of the gems yourself. The uniqueness of the mineral and the high quality that it produces makes it the ideal state gemstone. Especially given how tied into the local geology it is, having been formed in conjunction with the other state symbols, serpentine and gold.

State Fossil: Smilodon fatalis (saber-toothed cat)

CHAPTER 792
An act to add Section 425. 7 of the Government Code, relating to State Fossil.

The people of the State of California do enact as follows:
SECTION 1. Section 425.7 is added to the Government Code, to read:
425.7. The saber-toothed cat (Smilodon californicus) is the official State Fossil.

Fossil of Smilodon fatalis found in the La Brea Tar Pits. Image courtesy of tarpits.org.

Smilodon fatalis, more commonly known as the saber-toothed cat, is member of the Felidae family that went extinct around 10,000 years ago, towards the end of the last ice age. Although, frequently called a "tiger" Smilodon is not actually closely related to modern day tigers, or any modern day cat really. Smilodon falls into the subfamily, Machairodontinae, which is separate from all modern day cats. Smilodon fossil remains are known from North America and the Pacific regions of South America. Although, often depicted as living in caves, Smilodon fatalis is more commonly found within plains or woodland deposits, and likely lived as an ambush predator. The skeleton of Smilodon supports this theory, since it is robust with a short tail, indicated it did not run down its prey. Smilodon fatalis grew up to 5-7 feet long and 3.5 feet high at the shoulder, weighing ~350-600 lbs. Originally, it was thought that the saber teeth were used to grapple and hold on to the prey, however they are not strong enough to do this and would result in a lot of broken teeth. It is now hypothesized that the saber teeth were used to deliver a mortal stab wound while the animal then waited for its prey to die. Smilodon fatalis was initially described in 1868 by Leidy from a sample found in Texas.

Reconstruction of Smilodon fatalis. Image courtesy of cenozoiclife.blogspot.com.

Over 130,000 different Smilodon specimens (at least 2,000 individuals) have been found in California, primarily within the Rancho La Brea asphalt deposits (the tar pits) and is the second most common animal found there. The La Brea Tar Pits formed from crude oil that seeped to the surface and partially evaporated, leaving only the heavy tar behind. Animals would get stuck, and eventually enveloped, by the tar after they died from lack of food or water. The Smilodon bones found within the pits were discovered to have what would normally be debilitating injuries that had healed over. This indicates that these animals were possibly cared for by other saber-toothed cats, as in a familial setting. So unlike most cats which are solitary hunters, Smilodon appeared to be a pack animal, similar to modern day lions.

State Dinosaur: Augustynolophus morrisi

AB 1540
Purpose of the bill. According to the author’s office, “the Augustynolophus morissi is a unique dinosaur that has only been found in California. Seven states, as well as the District of Columbia, have declared a state dinosaur to pay homage to the original creatures to walk the land. California now has the opportunity to recognize an important part of our history. A state dinosaur is essential to California’s society because it nurtures an educational opportunity for the youngest Californian’s to become interested in paleontology, and S.T.E.M (Science, technology, engineering, and mathematics) as a whole.”

Augustynolophus morissi. The Augustynolophus morissi is a saurolophine hadrosaur dinosaur. Hadrosaurs are also known as the duck-billed dinosaurs. Additionally, Augustynolophus morrisi is a herbivorous dinosaur.

Due to many geological and geographical factors, the record of dinosaurs within California is quite slim. Augustynolophus morissi roamed California during the Maastrichtian Age, which makes it a contemporary of other well-known dinosaurs such as Tyrannosaurus and Triceratops. The fossils have been found nowhere else in the world.

The Augustynolophus morissi specimens were discovered, between 1939 and 1940, by crews from the California Institute of Technology who collected two partial hadrosaurid skeletons from Moreno Formation of the Panoche Hills of Fresno County. It was originally thought that these animals belonged to an already-known genus – Saurolophus – however, when a more in-depth study took place, it was revealed that the cranial structure was vastly different, and therefore, determined to be a separate species.

The species is named after two notable Californians. The generic name derives from a combination of Mrs. Gretchen Augustyn and the suffix "-lophus," referring to its relation to Saurolophus. The specific name refers to paleontologist, Dr. William J. Morris.

AB 1540 designates the Augustynolophus morrisi as the state dinosaur.

Reconstruction of Augustynolophus morrisi. Image courtesy of Smithsonian Magazine.

Augustynolophus morrisi is a hadrosaurid dinosaur from the Panoche Hills of Fresno County, California. The holotype specimen was originally collected in 1939-1940 and was initially identified as a new species of Saurolophus. Another specimen was discovered and collected in 1941 with the same diagnosis. Recently, further preparation of the skull material (pictured below) warranted naming the dinosaur as a new genus, Augustynolophus (Prieto-Márquez et al., 2014). The identification of the new genus was based on the unique nasal crest. Hadrosaurid dinosaurs are herbivorous dinosaurs that can be broken into two major clades (groups), the hollow-crested Lambeosaurinae (such as Parasaurolophus) and the non-crested/solid-crested Saurolophinae, of which Augustynolophus is a member. The group of dinosaurs that now contains Saurolophus and Augustynolophus is known as the Saurolophini Tribe and is found right up until the End Cretaceous extinction event, with Augustynolophus being found in the 66 million year old Moreno Formation.