Tuesday, June 16, 2026

Geology of the National Parks in Pictures - Cuyahoga Valley National Park

My next post about the Geology of the National Parks Through Pictures is from a trip to Ohio shortly after we moved to New York for a memorial service for my dear friend Dale.


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.

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Obligatory entrance sign shot.

Cuyahoga Valley National Park is actually a rather large park with many things to do and places to go within the park. It is essentially an urban national park, sitting just outside of Cleveland and Akron, Ohio. Since our time within the park was limited and we could not do everything possible, we decided to do a hike up to Brandywine Falls and take a train ride through the park.

Brandywine Falls

The hike up to Brandywine Falls and the falls themselves show a wonderful cross section of the geology available within the park. As you can see in the image of the falls above, there are three main rock formations within the park. Starting with the bottom, and the oldest, is the Cleveland Shale, which sits at the base of the falls. The Cleveland Shale is Late Devonian in age (~350 to 400 million years old) and is mostly a black shale, meaning that it is rich in organic material (e.g. oil and gas). The Cleveland Shale is assumed to have been deposited in a fairly shallow water environment with low oxygen levels. These low oxygen levels have led to the preservation of a number of fossils within the formation including 22 species of jawed fishes, including the 40 foot long Dunkleosteus, and one of the earliest known sharks, Cladoselache.


Sitting above the Cleveland Shale, and encompassing the majority of the height of the falls, is the Bedford Shale. The Bedford Shale is also Late Devonian in age (~350 million years old), and represents a shallowing of the water that was in the region. The rock units are interbedded shales, siltstones, and sandstones that progressively get more sandy as you work your upward through the unit. A large amount of these deposits were laid down within river deltas that meandered back and forth across the region. These interbedded deposits are what give the formation the multiple thin beds as seen in the close up above. The Bedford Shale rocks are what creates the rock wall along the edge boardwalk trail towards the falls (pictured above). 

Downward view of Brandywine Falls

The uppermost layer that comprises the falls, and the capstone of the falls, is the erosion resistant Berea Sandstone. The resistance to erosion of this layer is what created the falls in the first place, preventing the breakdown of the much softer layers below (the Bedford Shale). The Berea Sandstone is also Late Devonian in age (~350 million years old), and continues the environmental shallowing seen in the lower Bedford Shale. The Berea Sandstone is made up of interbedded sandstones and siltstones, with mostly sandstone, that were deposited just offshore within the deltas of nearby rivers. This sandstone, because of the porosity of the rock (gaps in between the sand grains), makes this formation a valuable oil reservoir, when found deeper underground.  


There are a few other geological formations within the park, most of which are related to the glacier deposits from the Ice Age, ~2 million to 10,000 years ago. However, we didn't see most of those. We were able to take a train ride along the Cuyahoga River, which makes its way across the entire park. Our train ride took us along the river for pretty much the entirety of the trip and it was definitely running very high/flooding while we were there. While the picture above you can't see how high the river really is, the picture below shows a little better the full extent of the water levels. The ancestor river to the Cuyahoga River first began to form 150 million years ago and continued to erode down into the landscape forming the prehistoric river valley until the glaciers damned up the river and filled that ancestral valley with till, i.e. glacial sediment.  


As the glaciers started to melt away, the Cuyahoga River was reformed as a glacial outwash stream, flowing south away from the current Lake Erie. Due to the topography of the landscape, and despite the glaciers being towards the north blocking the way, the river still wanted to flow towards the direction of modern day Lake Erie. As this new Cuyahoga River carved down into the landscape as a glacial outwash stream, it eventually hit the topographical high around the city of Akron. When it hit this high it also rediscovered the ancestral river valley and was able to excavated the glacial sediments within it. Within the ancestral valley, the course of this new Cuyahoga River was redirected back towards the north from the City of Akron in a big U-shaped bend. This bend is what has caused the river to be known as the crooked path. Even the name of the valley is derived from what the Native Americans named the river, “Ka-ih-ogh-ha”, meaning crooked. 



Alongside the river, the Ohio & Erie Canal was formed back in the 1800's and maintained through the early 1900's. This canal route contained several locks used to raise and lower boats along the waterway. Lock 29, along the Cuyahoga River, is a former Ohio & Erie Canal lock where the original construction sandstone blocks can still be seen. All the other locks had their sandstone blocks replaced in the early 1900's when their sandstone blocks had deteriorated. However, Lock 29 had it's masonry redone in 1882, and therefore the sandstone blocks were still in good condition during the renovation of the other locks. Therefore, while all those other locks were converted to concrete, we still have the original sandstone here. The sandstone used for these locks was the aforementioned Berea Sandstone. Because it could be quarried locally and was extremely durable (hence waterfall), it was chosen as the ideal rock to make the lock out of. Blocks of sandstone were taken from the nearby Deep Lock Quarry less than 2 miles away.

References
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Thursday, May 28, 2026

Geology of the National Parks in Pictures - Herbert Hoover National Historic Site

My next post about the Geology of the National Parks Through Pictures is from our move across the country from Utah to New York. Along the way we visited 13 National Parks as well as some other sites. This was the 13th, and final, National Park along the way.


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.

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Obligatory entrance sign photo


Herbert Hoover is notably the only geologist (to date) to have become president. His wife, Lou, was also a geologist, and the first woman to receive a geology degree from Stanford University. And while you would hope that a geologist would have many geological tidbits around his National Historic Site, there are not many across the park.

Schoolhouse

In front of the schoolhouse there is a sign that has a little geological tidbit about Hoover. It is assumed that Hoover attended school here from age 5 until ~10 or 11, after which he went to live in Oregon with his uncle after he was orphaned. Eventually, he attended Stanford and received a degree as a Geological Mining Engineer, with the photo in front of the school house here, showing Hoover as part of a geological survey squad in 1893.

Herbert Hoover Birthplace Cottage

Another site within the park, the Birthplace cottage, has some geology to it. The foundation of the birthplace cottage had been changed over the years, with the original foundation having been constructed using local boulders found on the prairie. The cottage was then purchased by another family and moved in 1889. However, it was then restored to its original location in 1934, when the Hoover family repurchased it. The stones used for the current foundation is a "local stone", however I can't find any more information on the specific rocks used. My guess is that it is a dolomite (a type of limestone), because the park sits upon several dolomite formations.

Geological map of Herbert Hoover National Historic Site and surrounding area. Image courtesy of the NPS.


The majority of the park sits upon the Silurian Age (~430 million years old) Scotch Grove Formation and the ~425 million year old (still Silurian) Gower Formation. Both of these are fossiliferous dolomites that formed in fairly shallow marine environments. These rocks are slightly younger than the bedrock below the nearby Effigy Mounds National Monument. If the stones for the birthplace cottage were quarried locally, it is likely that one of these two formations were the ones quarried. 


One of the most notable geologically related construction stones are the marble slabs used for the grave markers for both President Hoover and his wife, Lou. The marble slabs are noted as "Vermont white marble", however there is little information besides this to identify the quarry, region, or formation of the marble use. It is assumed that, due to the time period that these slabs would have been quarried, and the importance of the memorial (being a former president) that these are likely from the Danby Imperial quarry.


The Danby quarry is the largest underground marble quarry in the world. This quarry, located in the northeast flank of Dorset Mountain in Vermont, mines the Columbian member of the Lower Ordovician Shelburne Formation (~480 million years ago). These marbles were originally deposited as a limestone within a shallow marine environment. Then burial under other rocks and metamorphism from mountain building heated the limestones up and folded them, altering the minerology to produce the marbles as they are today. Blocks of marble from this quarry have been used in the New York Public Library, the Jefferson Memorial, Harvard Medical School, the U.S. Senate Building, Arlington National Amphitheater, the Supreme Court, and the United Nations building.


Although it is possible to find some of the bedrock along local stream channels, the majority of the bedrock within the park is located fairly deeply beneath glacial sediments (hence the original boulders used for the birthplace foundation) that were deposited during the early and middle Pleistocene Epoch (about 2.6 million years ago to 500,000 years ago). These glacial deposits are known as the Pre-Illinoian Alburnett and Wolf Creek formations, which comprise mostly of till, a glacial deposit that is essentially a clay rich mishmash of everything that can be thrown into one pile. Think of a glacier scouring the surface of the earth and then just dumping everything it picks up into a pile like a conveyor belt. That is till. 

References
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Thursday, May 14, 2026

Geology of the National Parks in Pictures - Effigy Mounds National Monument

My next post about the Geology of the National Parks Through Pictures is from our move across the country from Utah to New York. Along the way we visited 13 National Parks as well as some other sites. This was the 12th National Park along the way.


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.

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Obligatory entrance sign


Great Bear Mound

Created by ancestral people known as the Effigy Moundbuilders, the mounds served several different purposes. Primarily they were used for human burial purposes by piling soil, sod, and clay, along with other materials, in the shapes of animals over the bodies of the deceased. These shapes include birds, bears, water spirits, deer, turtles, beaver, buffalo, canines, and other animals, however the shapes are often difficult to identify along when viewed at ground level. The Lidar image below gives an excellent example of an aerial view of the mounds, with each of these marching bear mounds reaching around 20 meters in length. 

Lidar of the Marching Bear Group in the southern portion of the park. Image courtesy of the NPS via Wikimedia.

Found throughout the region, most of the mounds within the park are conical in design. However mounds, like the Great Bear Mound, form the shape of animals (pictured from ground level above). There are also linear and compound designs found within the park, but in far fewer numbers.

Types of mounds found at Effigy Mounds NM. Image courtesy of National Park Planner. 


The construction of at least some of the mounds began by first removing the sod or leafy humus from the forest floor. A square shaped pit was then dug out and human bodies were laid to rest within the pit. One of the excavated mounds held four bodies. Soil was then piled up upon the bodies along with rocks and clam shells. Cremation ashes mixed with baked reddish clay were mixed in with the final layer of earth on top of the mound. 


The location of the mounds, especially within this region, were generally along elevated surfaces. These mounds, in the picture above, are the end of a linear series of conical mounds that end at a promontory overlooking the Mississippi River (below). By placing the mounds at an elevated location they remained isolated from the flooding common to the shores of the Mississippi River.


All of the mounds within the park are located upon an elevated plain overlooking the Mississippi River, with tributary rivers, like the Yellow River adjacent to the entrance and Visitor's Center, carving deep valleys within the plateau. The plateau is comprised primarily dolostone (a more weathering resistant variety of limestone) and sandstone. Both provide a surface that is slow to erode away.

Prairie du Chien Group seen along the hike up to the mound plateau on the northern portion of the park. 

Geologically, the mounds sit upon the Lower Ordovician age (~480 million years ago) Oneota and Shakopee Formations, which make up the Prairie du Chien Group. These beds are primarily made up of dolomite, quartz sandstone, and sandy dolomite. There is also significant amounts of chert within the beds. Below the Prairie du Chien Group, you can also see the older, Upper Cambrian in age (~490 million years old), Jordan Sandstone along the parts of the park that border the Yellow River. Both of these formations were deposited when the area was inundated by a vast sea. The sea ebbed and flowed across the land, alternating periods of deep water deposits as well as shallow coastline deposits. When the water was shallower, sand would be deposited along the coastal waters. As the water deepened, limestones and dolostones (a variety of limestone that has a high concentration of magnesium within the crystal structure), were deposited from the bodies of sea life that slowly died over time.    


Glacially, Effigy Mounds is in the Driftless Area of Iowa, meaning that it was never covered with glaciers. While these elevated plateaus did not feel the effects of glacial activity, the neighboring Mississippi River was carved out by glacial meltwaters, with glacial debris filling up the river valley up to 150 feet. 

3 Mounds

While the park is primarily an archeological site, geology plays a major role. By providing the elevated location for the mounds, to suppling the materials used that were incorporated within the mounds, such as the dolostone, clay, along with the soil and sod, geology was a major contributor to the building of the Effigy Mounds. 

References
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Thursday, April 30, 2026

Geology of the National Parks in Pictures - Pipestone National Monument

My next post about the Geology of the National Parks Through Pictures is from our move across the country from Utah to New York. Along the way we visited 13 National Parks as well as some other sites. This was the 11th National Park along the way.


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.

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Obligatory entrance sign photo

Pipestone National Monument is a sacred Native American site, known as Inyan Sa K'api to the Dakota People. It is here that they quarry the pipestone rock in order to carve pipes for ceremonial use, as well as other objects with smaller pieces of the rock. 


The geology of Pipestone National Monument has three distinct rock types. The two primary rock types are quartzite and the pipestone layer. Seen in the picture above, the floor of this outcrop quarry is the Sioux Quartzite. At the base of the wall in the picture is a thin red layer. This layer is the pipestone layer, a rock known as catlinite or Siouz Argillite. Above the Catlinite is the continuation of the Sioux Quartzite, with the third type of rock in the park, conglomerate, above the quartzite. 


The Sioux Quartzite initially formed ~1.6 billion years ago along a braided river system. This is similar to what is seen in many rocky mountains and colder climate regions today (such as Canada's Banff National Park). Within the quartzite formation, several different types of deposits can be seen including different portions of the braided river system like channel-floor lag deposits, in-channel deposits, nearly filled channel deposits, and vertical accretion deposits. The sand grains within the quartzite are primarily comprised of quartz and were eventually cemented together with silica (dissolved sand grains) forming a quartz sandstone. 


The red colors within the quartzite are caused by various minute amounts of iron oxide (AKA hematite, AKA rust). Over time, the quartz sandstone was buried and subjected to extreme heats and pressures. This essentially melted the quartz sand grains and silica cement, intermixing them to produce a solid mass of quartz. The result is a metamorphic rock known as a quartzite, a rock that is harder than ordinary steel. 


Within the Sioux Quartzite is a layer of clay, which is the pipestone layer, catlinite. The clay was deposited within the braided river system along the floodplains. When rivers flood, they break across their natural levees and deposit clay and other fine sediment along the neighboring shorelines. Within braided river systems these clay deposits are rarely preserved, though, because eventually they are eroded away as the river system meanders across the landscape. Despite the odds, this deposit of clay was preserved by a fast burial of sand on top of the clay, preventing erosion.


Named after the American Painter, George Catlin, who visited the quarries in Minnesota in 1835, catlinite is unique to this region. Catlinite is made up of a unique combination of several clay minerals including pyrophyllite, diaspore, muscovite, kaolinite, and traces of hematite (producing the red, rust, color). Most notably, there is little to no quartz found within the catlinite deposit. The resulting rock is very dense but very soft, about the same hardness as a human finger nail, making it remarkably easy to carve. The same metamorphic processes that happened to the surrounding Sioux Quartzite, were also inflicted upon the catlinite, producing this low grade metamorphic rock. 

Quarry representation. Courtesy of the NPS. 

In the words of George Catlin:
"For many miles we had the Coteau in view in the distance before us, which looked like a blue cloud settling down in the horizon . . . On the very top of this mound or ridge, we found the far-famed quarry or fountain of the Red Pipe, which is truly an anomaly in nature. The principal and most striking feature of this place, is a perpendicular wall of close-grained, compact quartz, of twenty-five and thirty feet in elevation, running nearly North and South with its face to the West, exhibiting a front of nearly two miles in length, when it disappears at both ends by running under the prairie . . . At the base of this wall there is a level prairie, of half a mile in width, running parallel to it; in any and all parts of which, the Indians procure the red stone for their pipes, by digging through the soil and several slaty layers of the red stone, to the depth of four or five feet. From the very numerous marks of ancient and modern diggings or excavations, it would appear that this place has been for many centuries resorted to for the red stone; and from the great number of graves and remains of ancient fortifications in its vicinity, it would seem, as well as from their actual traditions, that the Indian tribes have long held this place in high superstitious estimation; and also that it has been the resort of different tribes, who have made their regular pilgrimages here to renew their pipes.”
(Quote from Gurney and Heyman 2002)


While extracting the pipestone from the quarry, the overlying quartzite is slowly removed. There are several rubble piles, like pictured in the images above and below, that are produced from the overburden of the unneeded quartzite above the pipestone layer. The quarries are still mined today by Native American groups and have been for centuries. In the area surrounding the below rubble pile, Native Americans first discovered the pipestone. In this region the pipestone has had the hematite partially leached from the stone, causing speckles within the rock. These speckles are termed "spotted" pipestone. 


The overlying conglomerate, as well as other features throughout the park, including glacial erratics (known as the Three Maidens towards the entrance of the park), striations (scratches in the quartzite), and till (the overlying conglomerate and other sediment), represent the remains of glacial activity throughout the park. 


The glacial deposits within the park are thought to date between 800,000 and 500,000 years ago, some of the oldest in North America. While there are many significantly younger glacial deposits across the continental US, they did not cover the park. These glacial deposits are from the Ice Age, when vast sheets of ice covered the northern portions of the continent, dragging rocks and other debris along their bases. As they reached their limits and started to melt away, the dropped the materials they were carrying, often in a conveyor belt fashion, forming piles along their furthest extents. These piles are what are known as till, and include other artifacts like random boulders known as erratics. 

Winnewissa Falls

Through the park runs Pipestone Creek, forming Winnewissa Falls (as seen above). The water falls are produced as the creek flows over the resistant Sioux Quartzite, the to excavated lower unit of the Sioux Quartzite below the Pipestone layer. 

References
Gurney, G. and T. T. Heyman, editors. 2002. George Catlin and his Indian Gallery. Smithsonian American Art Museum, Washington, DC and W. W. Norton and Company, New York, New York.
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Thursday, April 16, 2026

Geology of the National Parks in Pictures - Minuteman Missile National Historic Site

My next post about the Geology of the National Parks Through Pictures is from our move across the country from Utah to New York. Along the way we visited 13 National Parks as well as some other sites. This was the 10th National Park along the way.


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.

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Obligatory entrance sign photo

Minuteman Missile National Historic Site protects two locations (plus the Visitor's Center), as representatives of the once sprawling Minuteman Missile field that covered the far western portion of South Dakota. In total, there were 15 Launch Control Facilities and 150 Missile Silos the held the Minuteman Intercontinental Ballistic Missiles. The two locations preserved are one of the Launch Control Facilities, Delta-01, and the corresponding Missile Sile (Launch Facility), Delta-09. Delta-01 was only accessible via a tour, and since we were pressed for time, we only visited Delta-09 and the Visitor's Center.


The Minuteman Missile Silo Delta-09 sits within the American Great Plains, a expansive region with little topography. However, the site here does sit very close to the Badlands National Park just to the south. Per the National Park's page: 
Landforms in the Great Plains are unglaciated and retain soils formed by shallow seas that covered the region approximately seventy-five million years ago.... The seas that once covered South Dakota's Western Plains deposited limestone and sandstone overlain by soft Pierre shale.
Looking at the missile silo cap at Delta-09

The geological description of the park is a little simplistic, however there is not much that can be discerned from other online sources. They even state in their combined Historic Structures Report, Cultural Landscape Report, and Environmental Assessment report, which often contains geological information on many of the parks within the NPS, that since any proposed work would not disturb the bedrock that "further analysis of geology will be dismissed". So while they have no intention of getting into the geology of the site, if we look back into the original structure, the missile silo was obviously dug into the geological layers of the region. 

Looking down at the now defunct missile, within Missile Silo Delta-09

The missile silo itself is 12 feet in diameter and 80 feet deep. You can take a look down it, as seen above, when visiting the site. The Visitor's Center also has the nice diagram below, however, it also is lacking in geological context. 

Diagram of the Delta-09 Missile Silo

Looking at a geological map of the region does elucidate some of the geology. The map below shows a snippet of the regional geology map with a close up view of the geology of the Delta-09 site, marked by the "X". Delta-09 sits within the Qe deposit. This is wind blown sand (eolian), that dates back to the Eocene (~34 million years old). This sand is far younger than the denoted Pierre Shale at 75 million years old listed on the website. The sand here is predominantly wind blown sediment that is reworked sands from the older rocks below. 

Snippet of the Delta-09 Geology Map. Full map courtesy of the National Geologic Map Database.

On the map to the south of the Delta-09 site, you can see a different, darker shade of orange, Qoa. Qoa, the Older Alluvium, represents a different form of Eocene deposit that also formed from the reworking of even older rocks, soils, and sediments. Both of these "Q" (Quaternary), layers sit upon the thicker bedrock of the region. However, through the Qoa deposit, we can catch a glimpse of some of the true bedrock of the region. The description of the geological layers to the right of the map lists them in reverse chronological order. This means that the oldest layers are located at the bottom of the legend, with progressively younger layers stacked on top. The Pierre Shale is indeed the oldest, and thickest, bedrock layer within this region and although it only peaks out a little bit in the area of Delta-09, it is definitely a major rock unit below the surface. The Pierre Shale is Cretaceous in Age (~75 to 69 million years old) and formed when this area, and much of central North America, was covered in a vast inland sea known as the Western Interior Seaway. Within the Pierre Shale, several fossils can be found in nearby Badlands National Park, such as ammonites and mosasaurs. These lived at the same time as the dinosaurs, but since this area was covered in water during the Age of the Dinosaurs, dinosaurs were not to be found. 


The next rock unit above the Pierre Shale within this region, and likely can be found along the walls of the missile silo, is the Chadron Formation. The Chadron Formation is Eocene in age (~37 to 34.3 million years old) and was formed along an ancient river floodplain. The Chadron Formation is made up of light gray claystone beds and represent an environment similar to the Everglades today. Fossils that can be found within Badlands NP within the Chadron are alligators, early horses, and the large brontothere (AKA titanothere) mammals. Within this area though, the Chadron Formation is likely a thin layer, especially compared to the outcropping within Badlands NP. 

References
https://www.nps.gov/articles/000/badl-geologic-formations.htm
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