Tuesday, February 26, 2019

Geology of the National Parks Through Pictures - The National Mall

My next post about the Geology of the National Parks Through Pictures is about some parks visited a long time ago within Washington D.C.

You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website Dinojim.com.


Looking down the National Mall at the Capitol Building (circa 1995).

Originally Washington D.C. started out as a tidal flat wetland with three different sides surrounded by water: the Potomac River on the south, Rock Creek to the west, and the Anacostia River to the east. During the 1800's and 1900's the land was drastically altered by the construction of new buildings and roads, dump sites (such as the present location of the Lincoln Memorial), and eventually dredging and draining of the rivers to expand the city itself. Seawall construction along the Anacostia river in the early 1900's eliminated ~90% of the remaining tidal marshes at that time.

Although most of the wetlands have been removed from the city by today, there are still a small percentage of wetlands scattered throughout the area.


Monday, February 25, 2019

Geology of the National Parks Through Pictures - Lincoln Memorial

My next post about the Geology of the National Parks Through Pictures is about some parks visited a long time ago within Washington D.C.

You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website Dinojim.com.


 View of the Lincoln Memorial from circa 1990. The Lincoln Memorial is composed of six different principle building stones from across the country. 

Sunday, February 24, 2019

Geology of the National Parks Through Pictures - FDR Memorial

My next post about the Geology of the National Parks Through Pictures is about some parks visited a long time ago within Washington D.C.

You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website Dinojim.com.


The FDR Memorial is built with a reddish-grey granite called Carnelian Granite. The granite was quarried from a quarry near Milbank, South Dakota.

Saturday, February 23, 2019

Geological State Symbols Across America - Delaware

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


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 Mineral: Sillimanite                                            1977
State Fossil: Belemnitella americana (Belemnite)       1996

State Mineral: Sillimanite


WHEREAS, members of the Delaware Mineralogical Society have found that the State of Delaware has omitted from the Delaware Code the official designation of a State mineral; and 

WHEREAS, many states have designated an official State mineral to accompany their State flag, State flower, State bird and State bug; and 

WHEREAS, the mineral herein designated as the official State mineral is fitting to accompany Delaware's other official symbols; and 

WHEREAS, the proposed State mineral, Stillimanite (sp), is widespread throughout the schists of the Delaware Piedmont and occurs as large masses and stream-rounded boulders at the Brandywine Springs State Park; and 

WHEREAS, the mineral Stillimanite (sp) is suitable for lapidary work and under the name Fibrolite it was recognized by geologists in Delaware prior to 1830. 


Section 1. Amend Chapter 3, Title 29, Delaware Code by adding thereto a new section to be designated as 1310 to read as follows: 
"1310. State Mineral. The official State mineral for the State of Delaware shall be Stillimanite (sp)."
Sillimanite from Brandywine Springs, Delaware (mindat.org)

Sillimanite, misspelled "stillimanite" in the official state bill, is an aluminum silicate mineral with the formula Al2SiO5. It is actually one of three metamorphic minerals with the same chemical formula. These three minerals, kyanite, andalusite, and sillimanite, form what is known as a metamorphic series. Each of the three minerals, which are metamorphosed clay minerals from shales, form at different pressures and temperatures as seen in the phase diagram to the right, with sillimanite representing the highest temperature version of the minerals. The size of the minerals is directly tied to how long the metamorphic rocks were subjected to those specific temperatures and pressures. The larger the minerals, the longer they were at those specific conditions. 
metamorphic phase diagram (alexstrekeisen.it)

These three minerals are therefore good indicator minerals that tells scientists about what temperature and pressure was reached during metamorphism. Sillimanite can be brown, pale-green, grey, or white in color and it can be found in a variety of different forms including fibrous, radiating crystals, columnar, massive, and rounded crystals. Sillimanite is found within the metamorphic rocks schist or gneiss, and has a fairly high hardness; 6.5-7.5 on Moh's Hardness Scale. Sillimanite is named in honor of Benjamin Silliman (1779-1864), the earliest professor to teach mineralogy at Yale University. All three of the almunia-silicate minerals are mainly (95%) used as a refractory minerals, meaning they make bricks out the mineral for use in high temperature ovens; typically associated with iron and steel manufacturing.

Cat's eye sillimanite cabochon
from Madagascar (geology.com). 

Within Delaware, sillimanite is found within the Hoopes Reservoir and Brandywine Springs areas. Around Brandywine Springs, sillimanite occurs as remarkably pure boulder sized pieces, and can be found as stream-rounded boulders in the area. The large size of the sillimanite crystals indicates that these rocks underwent high temperature metamorphism for a long period of time. The sillimanite here is ~30% the fibrous variety, giving the mineral a wood-grain texture when broken. Within Delaware, sillimanite is not mined for refractories, instead it is can be cut into cabochon gems that show a "cat's eye" effect, when is it collected at all. The sillimanite from Delaware can be found within the Delaware Gneiss, which formed 1.5 to 1.2 billion years ago. The Delaware Gneiss is part of a larger structure called the Delaware Piedmont, a small part of the Appalachian Mountain system that extends from Georgia to Newfoundland. The piedmont formed from a series of tectonic events that raised the Appalachian Mountains between 470 and 440 million years ago. 

State Fossil: Belemnitella americana (Belminite)


Section 1. Amend Chapter 3 of Title 29 of the Delaware Code by adding thereto a new section to read: 
"§ 313. State fossil. 
The official State fossil is the belemnite."

Reconstruction of an extinct belemnitids, the animal from which a belemnite comes from (Klug et al., 2016).

Belemnites are the skeletal remains of an extinct group of cephalopods known as belemnitids. The belemnite is a cigar shaped, calcitic, chambered internal shell, which differs from the external shell of the closely related ammonites. Rarely does anything beyond this internal skeleton remain from the belemnites, although some soft tissue remains have been discovered giving scientists important clues into the morphology of these animals. The fossil is the part of the tail called the rostrum that was covered with a leathery skin. The rostrum was composed of calcite crystals that grew outwards producing growth rings, similar to tree rings. The rostrum likely acted as a counterbalance to the weight of the rest of the body, allowing easier maneuverability within the water column. Belemnites lived during the Jurassic and the Cretaceous, going extinct along with the non-avian dinosaurs at the end of the Cretaceous. These fossils are extremely useful in paleontological studies. If found in abundance, which they often are, the streamlined profile of the fossil allows scientists to determine current direction, by measuring the alignment of the fossils. Belemnites are also fantastic indicators of paleo-oceanic sea temperatures by measuring the oxygen isotopic ratios preserved within the fossils themselves. 

Belemnitella americana examples (delmnh.org). 

Belemnites are found in abundance in many parts of the globe including Europe and North America. Within Delaware, belemnites can be found in the Mount Laurel Formation, a 70 million year old Cretaceous shallow-sea, sandstone deposit. Fossil hunters are able to collect these fossils from the dredge spoil piles along the Chesapeake and Delaware Canals west of St. George. Different genera and species of belemnites can be identified based on the shape of its nib, the pointed end of the fossil, and the shape of its guard, the rest of the fossil. Belemnitella americana is a prolific species that can be found across eastern North America and Europe. It has a wide, flat nib and a moderately wide guard. Although they have a wide range of possible colors (red, brown, orange, blue, purple, violet or yellow and translucent) they also fluoresce under ultraviolet light.


Thursday, February 14, 2019

Geological State Symbols Across America - Connecticut

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


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 Mineral: Almandine Garnet                                            1977
State Fossil: Eubrontes giganteus Dinosaur Track                   1991
State Dinosaur: Dilophosaurus                                                2017

State Mineral: Almandine Garnet 
House Bill No. 5053 
PUBLIC ACT NO. 77-293 

The garnet shall be the state mineral.
Almandine garnet from the Carnegie Mellon Mineral Collection.

Garnet is typically thought of as one specific mineral, however garnet is actually a series of very similar minerals. This mineral series varies in chemical composition, resulting in different mineral names, however the chemical composition of all of the garnets share a generalized chemical composition: X3Y2(SiO4)3, where "X" can be Ca, Mg, Fe2+, or Mn2+, and "Y" can be Al, Fe3+, Mn3+, V3+, or Cr3+. Along with the different chemical compositions, there are different colors and hardnesses associated with each one as well. Crystals of garnet typically form in 12-sided "balls", that can be easy to identify within the rocks that they are found in. The name "garnet" comes from the Latin, "granatus" meaning "like a grain" because of this ball-crystal habit. Garnet is formed from the metamorphism of shale minerals, and can be found in most foliated metamorphic rocks such as schist and gneiss. Garnets can also be found in some igneous rocks including granites and granitic pegmatites. Garnet has been used as a gemstone since ancient Egypt, however recently garnet has obtained significant usage as an abrasive. Since garnet is a rather hard mineral and has no cleavage, it typically breaks into sharp edged fragments, and therefore produces a good grit for water-jet cutting or sandblasting. Garnet is a very common mineral and even high grade gemstone quality specimens can be fairly cheap.

The Connecticut Garnet Trail

Almandine garnet is one of the most popular and common varieties of garnet. This is partly because it is the garnet variety that has a deep red color, the color most people think of when they think of garnets. The chemical formula for almandine is Fe3Al2(SiO4)3 and the mineral has a hardness of 7-7.5, very high on Moh's Hardness Scale. Typical almandine is opaque, however it can sometimes be found in the translucent variety, which is much more common for gemstone use. Garnets in Connecticut are typically found within different formations of schist, a metamorphic rock. These schists can be found across the entire state including rocks that range in age from Cambrian to Devonian, where most of them are thought to have metamorphosed from pelitic shales. Many of the available garnet sites are highlighted along the Connecticut Garnet Trail (as seen on the map to the right). Almandine from Connecticut has been used not only for gemstones but also as an abrasive such as for sandpaper and nail-files. 

State Fossil: Eubrontes giganteus Dinosaur Track
Conn. Gen. Stat. § 3-110g

Section 3-110g - State fossil 
The dinosaur footprints of Eubrontes shall be the state fossil.

Conn. Gen. Stat. § 3-110g 
(P.A. 91-70.)
Eubrontes track specimen #YPM VP 003454
from the Peabody Museum at Yale. 

Dinosaur tracks are a special type of fossil referred to as a "trace fossil". A trace fossil is evidence that an animal had once been within an area but it is not the actual remains of the animal itself. Trace fossils can encompass a wide variety of features including worm burrows, foot prints, or even fossil poop (called coprolites). In many cases, trace fossils from an animal have the potential to far outnumber the amount of body fossils from that animal, because an animal can leave behind only one skeleton but they can leave behind countless footprints. Unfortunately, it is also very difficult to link most trace fossils back to the animal or animals that made them, and often that isn't even important to most scientists because it distracts from what the trace fossils are able to tell us. Trace fossils are the evidence of animal behavior. The record of behavior that is preserved by a trace fossil can include how it moved, how it responded to different stimuli, what it ate, or even how it ate. Trace fossils can also preserve the presence of animals that don't usually get preserved as body fossils, including most types of worms and insects. When identifying a trace fossils, ichnologists (the scientists who study trace fossils) will treat them in much the same way as body fossils. They are identified with a genus, or in the trace fossil sense an "ichnogenus", and an "ichnospecies", where the full name of the trace will be unique to that type of trace fossil.

Dinosaur State Park dinosaur trackway from 50campfires.com.

Eubrontes giganteus is a trace fossil of a footprint (pictured above right). Based on information gleaned from the trace, scientists were able to discover that it represented a bipedal (two-legged), carnivorous dinosaur. Some of that came from the tracks themselves and their shape, but some of it came from the body fossils of the animals than we knew lived at around the same time and location as these tracks were found. Dinosaur tracks were first described by Edward Hitchcock back in the mid 1800's from the Early Jurassic strata (rocks) from the Connecticut River Valley. His descriptions are the first described dinosaur tracks ever and he is considered to be one of the founders of modern ichnology. The original example of Eubrontes was discovered in what is now the Dinosaur Footprint Reservation in Holyoke, MA, from sandstones and mudstones that indicated a shallow lake environment. When Hitchcock first identified these tracks, and several similar tracks, he had named them multiple different names, with Eubrontes being one of the first names used. However, it was not THE first name used. The first name used was Ornithichnites, but this was eventually thrown out by later workers because it was a name used to describe a generalized bird track and not the animal in which made it. Hitchcock later used Eubrontes to identify the track maker, which he believed to be a large bird due to the similarity of the track to modern day birds. Although we know today that the identification of the track maker is a very difficult, if not an impossible, question to answer, it was not always the mind-set of scientists. Modern day ichnologists will identify a trace fossil based on the shape and structure of the trace, so Eubrontes is now known to encompass all similarly shaped footprints. Due to the dating of the tracks and what scientists know of the animals that were alive during the Early Jurassic, it is usually assumed that the Eubrontes tracks were created by the dinosaur Dilophosaurus, or by a closely related species. Although first discovered and described from Massachusetts, Eubrontes extends within the Connecticut River Valley down into Connecticut with several tracks identified within Dinosaur State Park (as pictured above to the left). The identification and naming of Eubrontes represents an important step in the science of ichnology and paleontology in general. 

State Dinosaur: Dilophosaurus
Substitute Senate Bill No. 1002 
Public Act No. 17-204 


Be it enacted by the Senate and House of Representatives in General Assembly convened: 
Sec. 4. (NEW) (Effective from passage) The Dilophosaurus shall be the state dinosaur.

By Eduard Solà - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=21099013

Made famous by Jurassic Park, Dilophosaurus was a small theropod dinosaur from the Early Jurassic of Arizona. The movie emphasized large neck flaps, on a relatively small dinosaur, that flapped open to distract its prey, giving the predator time to spit acid it its prey's eyes and eventually devour it. None of that was based in reality. In reality, Dilophosaurus was about 20 feet long and 8 feet tall (much bigger than its movie counterpart), with no acid spitting, or neck flaps to speak of. What the movie did get right were the two frills that formed ridges down the skull. The name "Dilophosaurus" even translates as two-crested lizard, that is how prominent these ridges are. Besides the frills, another characteristic of Dilophosaurus is that the premaxilla, the bone at the end of the snout, was loosely attached to the maxilla, the main tooth bearing bone. This can be seen as a kind of cleft in the upper jaw in the reconstruction below. This means that Dilophosaurus would have likely needed to kill its prey with its hands and feet, not relying on its fairly weak jaw as much. 

Reconstruction of Dilophosaurus at the St. George
Dinosaur Discovery Site at Johnson Farm.
Photo by Sarah Gibson, used with permission.

Dilophosaurus was originally discovered in 1940 by Jesse Williams, a Navajo trading post owner from Tuba City, Arizona. The remains were found within the Lower Jurassic Kayenta Formation and were eventually described by Sam Welles in 1954 and identified as a new species of Megalosaurus wetherilli. Welles eventually redescribed the bones based on some new specimens as a new genus in 1970, this time renaming the dinosaur Dilophosaurus wetherilli. Currently all of the known Dilophosaurus material has come from the Kayenta Formation of Arizona with some possible material from Utah. And that's it. There is some debate about who the track maker for the Eubrontes footprints (as described above) was. These footprints can be found from Connecticut to the southwestern corner of Utah at the St. George Dinosaur Discovery Site at Johnson Farm, and many other places as well. By analyzing the date of the formation which the tracks are located in, as well as the size and shape of the tracks, it makes it very likely that these tracks were made by Dilophosaurus. At least, the Utah tracks were. However, looking at the Connecticut tracks is a different matter. There is little evidence that the Eubrontes tracks in Connecticut could have been made by Dilophosaurus, especially given the large distance between the sites and the lack of widespread Dilophosaurus material. So although it is possible that the tracks could have been made by an animal related to Dilophosaurus with similar proportions, it's unlikely that Dilophosaurus was ever in the New England region of the US.

Olsen, Paul E., Joshua B. Smith, and Nicholas G. McDonald. "Type material of the type species of the classic theropod footprint genera Eubrontes, Anchisauripus, and Grallator (Early Jurassic, Hartford and Deerfield basins, Connecticut and Massachusetts, USA)." Journal of Vertebrate Paleontology 18.3 (1998): 586-601.
By Eduard Solà - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=21099013
Gay, Robert. "New specimens of Dilophosaurus wetherilli (Dinosauria: Theropoda) from the early Jurassic Kayenta Formation of northern Arizona." Mesa Southwest Museum Bulletin 8 (2001): 19-23.

Saturday, February 09, 2019

Geological State Symbols Across America - Colorado

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


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: Yule Marble                                                          2004
State Mineral:  Rhodochrosite                                                 2002
State Gemstone: Aquamarine                                                  1971
State Fossil: Stegosaurus                                                          1982

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

Black Canyon of the Gunnison National Park
Dinosaur National Monument
Hovenweep National Monument
Mesa Verde National Park
Rocky Mountain National Park
Yucca House National Monument

State Rock: Yule Marble
Be it enacted by the General Assembly of the State of Colorado: 

SECTION 1. Part 9 of article 80 of title 24, Colorado Revised Statutes, is amended BY THE ADDITION OF A NEW SECTION to read: 

24-80-912.7. State rock. Yule Marble is hereby made and declared to be the state rock of the state of Colorado.

The Colorado Yule Marble Quarry. Image courtesy of the Colorado Geological Survey.

Marble is a metamorphosed variety of the sedimentary rock limestone. This means that the original sedimentary rock underwent periods of increased temperatures and pressures to change the rock itself. The primary minerals in marble are calcite (CaCO3) or dolomite ((Ca,Mg)CO3) but it will usually have other mineral contaminates mixed in as well (i.e., clay, mica, quartz, pyrite, and iron oxide, etc.). Since, the primary mineral in marble is calcite, most marbles will have a white color with swirls of darker colors (the contaminates) but marbles can be found in many different colors depending on what impurities were present in the initial limestone. During metamorphism of the original limestone, the calcite is recrystallized to form interlocking crystals, which will usually destroy any remnants of the original rock, including any fossils present.

Tomb of the Unknown Soldier. Photo by Thomas Loker Photography (tloker.wordpress.com)

The unique feature of the Yule Marble, found near the town of Marble, Colorado, is that the marble is one of the purest marbles ever quarried (meaning it lacks most of those impurities). For this reason it was chosen as the decorative stone on the Lincoln Memorial in Washington DC. The Yule Marble started out as the dark-blue Mississippian age Leadville Limestone. During the Tertiary, parts of the Leadville Limestone underwent contact metamorphism along the edges in contact with the uplifted granitic Treasure Mountain dome. After recrystallization, the Leadville Limestone was metamorphosed into the distinctive white marble known today. Along with the Lincoln Memorial, Yule Marble has been used for the Tomb of the Unknown Soldier, which was the largest single piece of marble ever quarried at the time. They also supplied some of the national cemetery headstones. However due to problems financing and running the mine, not many other notable uses have been made of the Yule Marble.

State Mineral: Rhodochrosite 
Be it enacted by the General Assembly of the State of Colorado: 

SECTION 1. Part 9 of article 80 of title 24, Colorado Revised Statutes, is amended BY THE ADDITION OF A NEW SECTION to read: 

24-80-912.5. State mineral. Rhodochrosite is hereby made and declared to be the state mineral of the state of Colorado.
Samples of rhodochrosite cabochons from Argentina. Image courtesy of geology.com.

Rhodochrosite is a manganese carbonate mineral (chemical formula (Mn, Fe, Mg, Ca)CO3) with a light pink to bright red color. As you can see with the chemical formula the manganese is frequently replaced with other elements like iron, magnesium, and/or calcium. These substitutions present problems with providing definitive mineral properties since the substitutions cause the specific gravity, hardness, and color of the mineral to vary. Generally though, rhodochrosite has a hardness of 3.5-4 with 3 directions of perfect, rhombohedral cleavage. Rhodochrosite is often found in association with silver mines and is sometimes mined as a by-product in those mines. Rhodochrosite can also be found filling the veins and fractures within metamorphic rocks. In this instance, the minerals are often built up over time with separate mineralization events, each one possibly producing different shades of pink within the mineral. Rhodochrosite can be used as a manganese ore, however there is often not enough of it when found to make it economically viable. Since rhodochrosite is so soft, its use in even jewelry is limited, where it usually ends up being used just as a natural mineralogical sample.

Rhodochrosite crystals with tertahedrite from the Sweet Home Mine, Alma, Colorado. Image courtesy of the Colorado Geological Survey

Rhodochrosite, is extremely rare in well-formed crystals. That is the reason that the Sweet Home Mine, near Alma, Colorado is so unique (such as the sample to the right). This is one of the few mines in the world to produce specimen quality rhodochrosite samples. Formerly a silver mine that opened in 1873, the mine was leased to a rhodochrosite company who started excavating high grade rhodochrosite samples. They mine by blasting holes in the rock that are 2mx2mx2m, and continue the process forming tunnels. Once a potential rhodochrosite pocket is located, special tools are brought to carefully extract the specimens, where they are then taken to be cleaned and prepared for sale. The usually pink color, as seen in the image to the upper left, is not the only variety seen in Colorado samples. Colorado rhodochrosite also comes in a translucent red crystal variety that is recognized worldwide for its beauty (as seen in the image to the right). Beyond just the Sweet Home Mine, rhodochrosite can be found in 18 counties within Colorado, with the largest rhodochrosite crystal ever found, the 6.5 inch Alma King, being found within the Sweet Home Mine itself.

State Gemstone: Aquamarine
Chapter 325
An Act concerning state emblems, and providing for the designations of a state gemstone.
Be it enacted by the General Assembly of the State of Colorado:

Section 1. Article 8 of chapter 131, Colorado Revised Statutes 1963, as amended, is amended BY THE ADDITION OF A NEW SECTION to read:

131-8-12. State gemstone. The aquamarine is hereby made and declared to be the state gemstone of the state of Colorado.

L. 71: p. 1221, § 1. C.R.S. 1963: § 131-8-12.
An aquamarine crystal from the Shiga Valley of northern Pakistan. Image courtesy of Arkenstone, geology.com, and iRocks.com.

Aquamarine is a greenish blue variety of beryl (Be3Al2Si6O18), named for the seawater in which it looks like. It has a hardness of 7.5-8 and often forms perfect, six-sided prismatic crystals. Although it can be found in duller colors; when heated to very high temperatures the mineral attains its characteristic sky-blue color. Even though beryl, and therefore aquamarine, has a very high hardness, its uses seem to be generally limited to jewelry and display items. Crystals of aquamarine are relatively common, however they still demand a high price, due to this intrinsic beauty of the specimens. Display quality aquamarine crystals can be found in Brazil, Pakistan, China, Russia, Myanmar, as well as several localities within the United States, among other localities worldwide. Quality aquamarine specimens within the US can be found in Colorado, California, Idaho, Connecticut, and Massachusetts.

The location of the Tertiary Princeton batholith near Mt. Antero and White Mt. where the aquamarines in Colorado have been mined. Map courtesy of Switzer. 1939.

Prospecting for aquamarine began in the late 1800's in the Mt. Antero area of Colorado. Many aquamarine crystals have been found in vugs (holes) within granite pegmatites of the Tertiary Princeton batholith. There are several different types of pegmatites within this region, with two different beryl pegmatites, only one of which contains vugs, or pockets. It is this pegmatite that is the most economically viable for aquamarine specimens. These vuggy beryl pegmatites include not only aquamarine crystals but also crystals of other minerals like microcline, smoky quartz, albite, and fluorite. The veins and pegmatites where the aquamarine has been found are mostly contained within an area roughly 3 miles across; an area that contains the summits of Mt. Antero and White Mt. (as seen in the map to the left). These pegmatites formed at temperatures that ranged from 200°C up to 600°C. Other areas within Colorado that also contain quality aquamarine specimens include Mt. Baldwin and Mt. Princeton, which are both located nearby to White Mt. and Mt. Antero.

State Fossil: Stegosaurus
Executive Order D0002 82

WHEREAS, Colorado enjoys a long and colorful history which extends well into the prehistoric era in which numerous dinosaurs and other now-extinct flora and fauna flourished; and

WHEREAS, the Stegosaurus lived in Colorado 150 million years ago in the Mesozoic era during the Jurassic period; and

WHEREAS, there are only six skeletons of the Stegosaurus on public display in the United States, including one on public display at the Museum of Natural History in Denver, Colorado, which was found and dug up by a teacher and students at Canon City High School; and

WHEREAS, the Stegosaurus, like all dinosaurs, makes a continuing contribution to modern living through fossil fuels which are comprised of the remains of dinosaurs and other once-living matter from prehistoric times; and

WHEREAS, the Stegosaurus has stimulated the interest of numerous Colorado school children to participate in the political process through their efforts to have the Stegosaurus established as a state fossil by the Colorado General Assembly; and

WHEREAS, three other states have established state fossils; and

WHEREAS, the establishment of a state fossil for the State of Colorado would be a benefit to the tourism industry of the state and would provide a positive conclusion to the important effort of numerous school children in Colorado to participate in our political process;

NOW, THEREFORE, I, Richard D. Lamm, Governor of the State of Colorado, pursuant to the authority vested in me under the laws and constitution of the State of Colorado, DO HEREBY declare that the Stegosaurus shall be considered the State Fossil for the State of Colorado and shall remain as the State Fossil pursuant to this Executive Order until such time as the General Assembly takes action to establish a State Fossil by statute.

GIVEN under my hand and the Executive Seal of the State of Colorado, this 28th day of April, A.D., 1982.
Stegosaurus at the Field Museum, Chicago, IL. Photo by Jim Lehane.

Stegosaurus was one of the earliest dinosaur finds during the infamous Cope and Marsh Bone Wars (find out more about that here). The first Stegosaurus fossils were discovered in 1876 in the Morrison Formation of Colorado by M.P. Felch and were named by Marsh in 1877. The original fossils were discovered north of the town of Morrison, CO. The name Stegosaurus means roof lizard, a name that goes back to when Marsh first described the animal thinking that the plates laid flat along its back, creating a roof. It wasn't until Marsh discovered another example of Stegosaurus with the plates still in situ (in place) that he realized his mistake. About 80 specimens of Stegosaurus have since been discovered in the Morrison formation, stretching from Colorado to Wyoming.

was an herbivore, that lived about 150 million years ago during the Jurassic period. The animal is most well known for the twin row of bony plates that lined its back and a set of spikes on its tail. Scientists are not certain of the use of the plates and several theories have been postulated including defense, display, or even heating/cooling pads (blood vessels ran through the plates allowing the air/sun to heat or cool the plates as needed); however it is pretty universally accepted that the spikes at the end of the tail were for defensive purposes. One of the most commonly known "facts" about Stegosaurus was that it had a very small brain for the size of the animal (it is about the size of a bus, 30 ft in length, with a brain the size of a hot dog). Because of the comparably small size of the brain, scientists at one time thought that Stegosaurus must have had a second "brain", or nerve ball cluster, that operated as a second brain somewhere along the spinal column. This idea came from the discovery of an enlarged canal along the pelvic region, however this theory has since been rejected by scientists. Stegosaurus had a toothless beak, with rounded peg-like teeth further back in its mouth, and a weak jaw, so it likely ate low lying plants like ferns and cycads.


Thursday, February 07, 2019

Geology of the National Parks Through Picture - Fort Point NHS

My next post about the Geology of the National Parks Through Pictures is part of a series of parks that the wife and I hit while we were visiting the wineries in the Sonoma Valley.

You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website Dinojim.com.

This post relates to the California Geological State Symbols post that came out earlier this week.


The last National Park we visited on this trip was within the Golden Gate National Recreation Area. 
Our entrance sign traditional pic with the Golden Gate Bridge and part of Fort Point in the background.

Wednesday, February 06, 2019

Geology of the National Parks Through Pictures - Golden Gate NRA

My next post about the Geology of the National Parks Through Pictures is part of a series of parks that the wife and I hit while we were visiting the wineries in the Sonoma Valley.

You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website Dinojim.com.

This post relates to the California Geological State Symbols post that came out earlier this week.


Golden Gate National Recreation Area
Continuing our trip from the Muir Woods National Monument, we then travailed some of the Presidio's national parks, including taking pictures of the Golden Gate Bridge itself. We weren't able to visit a lot of the surrounding areas of the park but hopefully we will be able to visit them at a future date.

Arriving at the Golden Gate Bridge we went to take in the overlook of the bridge and got an eyeful of the famous San Francisco fog. The fog is produced when the hotter air located within the city itself and the surrounding areas come in contact with the cool air blowing in off the Pacific ocean. When these two air masses come in contact, the warmer air is forced upwards creating clouds, or in this instance, fog.

Monday, February 04, 2019

Geology of the National Parks Through Pictures - Muir Woods

My next post about the Geology of the National Parks Through Pictures is part of a series of parks that the wife and I hit while we were visiting the wineries in the Sonoma Valley.

You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website Dinojim.com.

This post relates to the California Geological State Symbols post that came out earlier this week.

There isn't a lot of geology at this park, but we got some great tree pictures.

 Our entrance sign photo.

Saturday, February 02, 2019

Geological State Symbols Across America - California

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


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

State Rock: Serpentine

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    
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
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)
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.

The fossilized remains of Augustynolophus morrisi. Image courtesy of Prieto−Márquez and Wagner, 2013.

The genus name Augustynolophus is in honor of Mrs. Gretchen Augustyn and her family, who had been instrumental supporters of the Dinosaur Institute of the Natural History Museum of Los Angeles County. The species name, morrisi, is named for paleontologist William J. Morris (1923-2000), who had significant contributions to the understanding of hadrosaurid dinosaurs Pacific Coast and the Western Interior of North America. The dinosaur was chosen as the state dinosaur in part to boost enthusiasm for paleontology and to highlight one of the few dinosaur fossils found within the state of California, which did not have much land above sea level during the Mesozoic.

Wiener, J. G. and Suchanek, T. H. (2008), THE BASIS FOR ECOTOXICOLOGICAL CONCERN IN AQUATIC ECOSYSTEMS CONTAMINATED BY HISTORICAL MERCURY MINING. Ecological Applications, 18: A3-A11. doi:10.1890/06-1939.1
Prieto−Márquez, A. and Wagner, J.R. 2013. A new species of saurolophine hadrosaurid dinosaur from the Late Cretaceous of the Pacific coast of North America. Acta Palaeontologica Polonica 58 (2): 255–268.
ALBERT PRIETO-MÁRQUEZ, JONATHAN R. WAGNER, PHIL R. BELL, LUIS M. CHIAPPE; The late-surviving ‘duck-billed’ dinosaur Augustynolophus from the upper Maastrichtian of western North America and crest evolution in Saurolophini. Geological Magazine ; 152 (2): 225–241. doi: https://doi.org/10.1017/S0016756814000284