Wednesday, August 20, 2014

Geology of the National Parks in Pictures - Craters of the Moon

The next up on my tour of the National Parks in pictures:

Craters of the Moon National Monument & Preserve

My standard park sign picture, but this time with the little one.

 Lava tube entrance.

 This one shows a pretty good view of the landscape that has many trees and shrubs but is still pretty barren.

A lot of dead trees hanging about.

 Climbing up the largest of the cinder cones, Inferno Cone.

 Panoramic view from the top of Inferno Cone.

 View from Inferno Cone of a couple of smaller cinder cones.

Some nice aa, splatter lava.

 View of a lava flow showing large chunks of volcanic rocks.

 Another view of the same lava flow, this time a little further up. You can see a nice transition from the pahoehoe to the aa style lava.

 Me entering one of the lava tubes.

 Some nice ribbon lava. I really love the fine cracks that run perpendicular to the ribbon folds.

View looking out of one of the smaller lava tubes, Dewdrop Cave.

Within the largest lava tube in the park, Indian Tunnel. Several places along the length of the tube, the ceiling has caved in giving visitors a nice walk even without the need of a headlamp.

Thursday, August 07, 2014

Geological State Symbols Across the US - #5 California

The next state up is California. Here are the stats:

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

State Rock: Serpentine

    California was the first state to identify a state rock, serpentine. 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 (often found in the form asbestos), lizardite, and antigorite, among others.

   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 allowed material to be "scraped" off of the subducting plate. These accretionary provinces contained large pockets of serpentine within them, providing California with an abundance of valuable serpentine minerals including chromite, magnesite, cinnebar, and most importantly at the time, asbestos. For this reason, as well as its soft nature making it an easy stone to polish and usage as an ornamental rock, it was designated as California's state rock.

    However, 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    

     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 found in association with quartz veins, as the one shown to the left from Placerville, California.

     Along with the identification of a state rock, California also identified a state mineral at the same time, gold. It is not hard to understand why. 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, two billion dollars 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. Due to the high specific gravity of gold (high density) and its resistance to oxidizing (tarnishing) as it is eroded out of the mountains it concentrates in rivers in 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
Benitoite from Benitoite Gem Mine, San Benito County, California (Type Locality for Benitoite)

     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. The mineral also fluoresces blue under ultraviolet light. Bernitoite 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 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. In 1907, George D. Louderback, identified and named the  unique and very rare mineral. Primarily bentitoite 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 serpentine, a primary mineral found within the state rock, serpentine.

     However rare and valuable the gem is, collectors and rockhounds 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.

State Fossil: Smilodon fatalis (saber-toothed cat)
     Smilodon fatalis, more commonly known as the saber-toothed cat, is an animal that went extinct around 13,000 years ago, towards the end of the last ice age. The saber-toothed cat is known from North America and the Pacific regions of South America. The reason that this animal was chosen for the state fossil of California is that over 1,200 different specimens 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.

     Although, often depicted as living in caves, Smilodon fatalis is more commonly found within plains or woodland deposits, and likely lived as am 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. Originally it was though 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.

    The La Brea Tar Pits, where the fossils are primarily found in California, formed from the crude oil that seeps to the surface and partially evaporates, 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 tar pits where known to the Native Americans in the region and were used as glue and waterproofing their boats and houses. In the early 1875 though, the fossil of a saber-toothed cat was found and described.


Previous States


Wednesday, August 06, 2014

Drunk on Geology - Field Assistant Ale

Along with the previous Drunk on Geology post (Lava Cap), another special bottle was produced by the Geological Society of America (GSA) for their 125th anniversary meeting. This one is the Field Assistant Ale by the Left Hand Brewing Company.

The beer is normally the Left Hand Brewing Company's Sawtooth Ale, with a special bottle designed by design agency Moxie Sozo and artist Andrea Oropeza. You can find Andrea's work on her website: Here is what she had to say about the process of creating the bottle:
Project done during my time in Moxie Sozo. I created a label design for the special edition of the Left Hand Brewing Co.'s Sawtooth Ale to celebrate the Geological Society of America's 125th anniversary. It was a quick turn around but in the end everything came out really good. They created coasters, t-shirts and beer labels for the party and for all guests to get one of this special beer with this design.
Thanks to Left Hand and to GSA to make me a part of this experience.
This specific project is outlined here: and you can see an image of the label sans bottle bellow (also illustrated in the available sticker).

GSA was giving these out, one per day, do everyone (of legal drinking age) at the conference so I was more than able to get my fair share of it (Thanks GSA!). This specialty bottle was a great addition to the 125th anniversary celebrations. 

If you look at the fourth picture down below, you will notice that they also produced some stickers with the bottle. Well, I have some extra of these stickers. Stickers will be given out to the first 4 people who tweet at me (@Jazinator) "I want to be your field assistant". I will contact those people for their mailing addresses. 

Sticker's available!!! Read directions above on how to obtain one.

Original label design by Andrea Oropeza.