The Geology of Death Valley National Park
For those of you who have been following my podcasts, you know that my husband and I are both geologists. I no longer practice geology and now I primarily teach high school. My husband however is a Professional Geologist in the State of New Hampshire and I “consult” off the record on some of his projects. Two geologists in the family is an interesting dynamic, geologists on a whole are a rather unique breed. When we graduated from UNH we had under 6 other students who were graduating with us with a BS in Geology. This also presents an interesting scenario when we travel and I find most people are excited to meet not one but two geologists. We are an anomaly. This brings me to my topic for today’s podcast, the geology of Death Valley National Park. Visiting all 63 National Parks is on our bucket list as it is on many others. We recently visited Death Valley National Park on my February Break from teaching and everyone we met when we introduced ourselves and got talking wanted us to talk about the geology of the park once they learned we were both geologists. Now, my “Wait I see a rock” t-shirt may be a dead giveaway and starts a lot of conversations but my husband tends to bring up that we are both geologists quite often. So, on this trip we found ourselves educating other visitors on the geologic processes that formed many of the features of the national park. The National Parks Service website for each of the parks has a great general overview of the geology, but if you have ever visited some of our nation's national parks, you will know they are not the most on-the-grid locations. That is part of the allure of visiting the parks. Chances are, you are not going to be able to load a website page to read about the park's geology while you are in the park, but you could download a podcast to listen to offline while you are in the park. That finally brings me to this season's podcast episodes. I will be talking about the geology of the parks that we have visited, starting with Episodes 1 and 2 on Death Valley National Park.
Every park has unique and varied landscapes and Death Valley is not unique in that respect. However, Death Valley’s landscapes are so much more varied and extreme than any other park we have visited thus far. In the confines of the park boundaries, you can experience elevations as tall as 11,049 feet at Telescope Peak to elevations 284 feet below sea level in Badwater Basin, the lowest point in the western hemisphere. Death Valley also has volcanic craters, sand dunes, sedimentary, metamorphic, and igneous peaks. Death Valley is located in the northern section of the Mohave Desert in the rain shadow of the Sierra Nevadas. Death Valley has a really ominous-sounding name which is rather deceiving. While it is brutally hot during the summer months, and one of the dried locations in the US, receiving on average only 2 inches of precipitation, if you visit during winter or early spring as we did, it is teeming with life. Death Valley National Park is the largest National Park in the lower 48. It is approximately the size of the entire State of Connecticut.
So, let’s go all the way back to the beginning of Death Valley’s geologic history. The Funeral Mountains in the eastern park boundary and the Panamint Mountains in the western park boundary are primarily metasedimentary, metamorphosed sandstones and limestones. These rocks indicate that Death Valley was a warm shallow sea throughout the Paleozoic Era. As the plate began to move and compress, the mountains were pushed up and the sea began to recede. Our continental crust is rather brittle with respect to the other layers of Earth, so this continued movement deformed and folded, faulted, and metamorphosed the rocks in the Funeral Mountains as pressure and temperature increased between the plates.
In Mosaic Canyon, you can see polished dolomite and the Mosaic Canyon Breccia which shows evidence of a glaciation period. The dolomites and conglomerates of this canyon were formed around the time that the first multicellular life was forming and before the formation of the supercontinent we all know and love, Pangea.
As Pangea was forming, the Fallon plate began a collision with the North American plate. At convergent plate boundaries, we either see mountain-building events like the Appalachians, Alps, and the Himalayas, or we see subduction recruiting in deformation and volcanism. In this case, the collision of the Fallon plate and the North American plate further deformed and folded the rocks in Mosaic Canyon. We see some intrusions of igneous rocks in the rocks of the western mountain ranges of Death Valley. As the Fallon subducted beneath the North American plate, the North American plate saw an uplift, and Death Valley went from a continental shelf under a sea to a terrestrial landmass.
The weakened crustal plate now faulted and folded was prime for hot molten lava to upwell from the mantle and erupt through these weak points. The volcanic activity originated in the northwest of Nevada. These first volcanos blanketed the valley with ash, cinders, and debris. The volcanic activity continued westward and a chain of volcanoes erupted from Furnace Creek to Shoshone. As the volcanoes continued to erupt they coated the Artist's Palette area in more ash and cinders creating the colorful reds and greens in the landscape and some of Death Valley’s famous borax deposits. The colors are a result of the chemical weathering of the metal deposits in the deposits. The reds and pinks come from oxidation of iron-rich hematite; the greens are from mica-rich volcanic ash deposits; and the purples from manganese.
3 million years ago, the tectonics of our crust changed and began to rift and pull apart. This tectonic activity is what formed Death Valley as we see it today with alternating mountain ranges and valleys running parallel to each other.
Around 20-16 Ma years ago, the Fallon Tectonic plate was completely subducted under the North American plate. The Pacific Plate and the North American plate are beginning to form the transverse plate boundary that we know as the San Andreas Fault and the areas of the park that had originally seen compressional forces are now starting to see shearing forces. The tectonic events from this point to the present are what shaped the park into how we see it now. During this time the basin and range were created. Dante’s Peak is one of the best points in the park to view the basin and range topography.
Death Valley was a series of lakes during the Pleistocene Ice Age. One of these lakes, Glacial Lake Manly was over 100 miles long and over 600 feet deep. Maps of these lakes remind me of the New York Finger Lakes which are remnants of the same ice sheet that created the glacial lakes in Death Valley. The remnants of these glacial lakes are the modern-day salt flats in the Park, such as Badwater and Devil’s Golf Course. These salt flats contain thick alluvial sediment beneath the salts.
There are several variables needed in order to even form a salt flat. First is the obvious source of salt, typically from a large drainage system like the Black Mountains. Secondly, a basin that is enclosed and does not drain into the ocean, washing away the salts. The salt pans in Death Valley are some of the largest on Earth.
Death Valley’s drainage basin is over 9,000 square miles, which is larger than my state of New Hampshire. Rain falls on the peaks of mountain ranges creating floods and dissolving the carbonate minerals. Temporary lakes are formed. Finally, an arid climate where the evaporation rate is greater than the precipitation rate. Badwater basin is primarily sodium chloride, otherwise known as table salt. Evaporate minerals such as borax, calcite, and gypsum can be found in the salt flats as well. As the climate warmed the lakes disappeared and left the salt deposits of the Death Valley Salt Pan and Badwater Basin behind.
Badwater Basin is the lowest point in North America at 282 Feet BELOW sea level You can locate Telescope Peak in the Panamint Range to the west; at 11,049 ft, this peak is over two miles (3.2 km) above you. Nowhere else in America can you see this amount of elevation relief. Looking behind you on the cliffs of the Black Mountains across the road, you will see a sign that indicates a Sea-level 282 feet above your head.
Badwater Basin is one of the largest protected salt flats in the world. A fault line exists at the base of the Black Mountains, and the Death Valley salt pan. Badwater Basin is slowly subsiding into this fault. This means the Basin will change in elevation over time, slipping even further below sea level. As recently as 2005, Death Valley received enough precipitation for Badwater Lake to form.
Zabriskie Point which is best viewed at sunrise contains remnants of these glacial lakes in its multicolored sediments. When the sun hits these sediments you can see layers of red, brown, and yellow minerals in the deposits.
The most recent volcanism in the park occurred approximately 2,100 years ago at Ubehebe Crater. The Ubehebe volcanic field contains several craters; the Ubehebe Crater is the largest of these craters. The craters were formed when molten magma came in contact with cold water, and the reaction produced steam. The steam built up so much pressure that it exploded throughout the surface to create the craters. Erosion continues to shape the landscape of Death Valley.
The most recent geologic formation in the park is likely the sand dunes. Six areas of sand dunes are located within Death Valley National Park. Eureka, Hidden, Panamint Valley, Ibex, Mesquite Flat, and Saline Sand Dune Systems. At the Eureka Sand Dunes, the dunes can reach over 700 feet high from the valley floor to the peak. In order for sand dunes to exist, there needs to be a source of sand. This source in Death valley comes from the eroded sedimentary mountain ranges within the park. The winds seem to always blow through the park and our trip to the park was no different. We woke to a sandstorm that was shaping the Mesquite Dunes across from Stovepipe Wells Village where we spent the night.
Death Valley may be a land of extremes, but the extremes are part of what makes this extraordinary place worth a visit. Death Valley is one of the hottest, driest, and lowest spots in North America and should make it to your bucket list as should every other National Park, Landmark, Site, Etc. Stay tuned for Part 2 on the mysterious sailing stones and the Death Valley Racetrack.
California Division of Mines and Geology. (2009, July 24). California Division of Mines and Geology Special Report 106 Geologic Features—Death Valley, California. California Division of Mines and Geology: Special Report 106 - Geologic Features—Death Valley, California (Contents). Retrieved April 30, 2022, from http://npshistory.com/publications/geology/state/ca/cdmg-sr-106/contents.htm
Miller, I. (2011). Two-stage formation of Death Valley. Geosphere, 7(1), 71-82. https://pubs.geoscienceworld.org/gsa/geosphere/article/7/1/171/132406/Two-stage-formation-of-Death-Valley
Miller, M. (2015). Geology of Death Valley: Landforms, Crustal Extension, Geologic History, Road Guides. Kendall Hunt Publishing Company.
National Parks Service. (2022, January 9). Geology - Death Valley National Park (US National Park Service). National Park Service. Retrieved April 30, 2022, from https://www.nps.gov/deva/learn/nature/geology.htm