Geography 368:
Desert Southwest

University of Wisconsin - Eau Claire

Day 1

Carrizo Plain and San Andreas Fault

Saturday October 13, 2012 was the first day of our adventure into the desert southwest. We arrived late the night before in Ontario, California which is just outside of Los Angeles. The southern California region of the country was quite a lot different from the one that we left in Eau Claire. The deciduous maple trees and coniferous pine trees all of us were accustomed to were replaced with Palm trees. The vegetation in general was much scarcer than in Wisconsin. Not to mention the part I am sure most of us found inviting, replacing subzero degree Celsius temperatures back home with temperatures in the 20-23°C (68-74.5°F) range. All of these differences were the exact reason we were there. To get a change of scenery and try to understand the geographical differences associated with another, drastically different climate zone.

The first stop of the day was more of a cultural aspect to geography rather than the physical aspect we investigated the rest of the trip. We stopped for lunch at an In-N-Out Burger, a cultural mainstay for this area of the country that was new to most of us. After our proverbial tanks were filled, we piled into our three rented vehicles and it was onward to the north.

After a few hours of driving north on Hwy 5 for the most part, we took a turn to the west and headed for Soda Lake Road. The primary reason for taking this route was the fact that Soda Lake Road runs parallel in close proximity to the San Andreas Fault line. The San Andreas Fault is a strike-slip fault. This means that there are two sections of earth’s crust that are moving parallel to each other in opposite directions. It is a very well know fault that travels the length of California. The area that we were able to observe the fault is known as the Carrizo Plain and there is an active effort by the state of California to preserve it in its natural state.

We pulled off to the side of the road at one point to observe a feature that was most interesting. It was a large (150-200m by 50-75m) flat expanse that was bright white. Upon further investigation the white color was due to a 2-5mm coating covering the dirt underneath. A quick taste-test revealed the substance to be salt. This feature was a dried section of lake bed from Soda Lake. The water evaporated and the heavy salts that were in solution were left behind.

Once we passed through the Carrizo Plain we were on our way west to the coast. We traveled through a section of California that was drastically different than the previous landscape. There was a significant increase in vegetation, hills and even wildlife. Spotting some ranchers on the side of the road almost made it feel like we were in Montana or Wyoming for a stretch. We didn’t make any stops through this area, but the scenery was a welcomed sight. Our destination for the next stop was Morro Bay. Located on the coast of California around 370km (230 miles) south-south east of San Francisco. Morro Bay is a popular tourist area.

Morro Rock

Other than the absolutely stunning beach and coastline of the bay, the featured attraction is a volcanic feature called Morro Rock. This large (around 150-200m tall) rock that protrudes from the bay is called a volcanic plug. What this means is that there was once a cinder cone volcano directly where Morro Rock sits. The volcano filled with extremely viscous (thick) magma. The magma was so thick that it could not make its way out of the volcano where it then solidified into the hard rock we see today. Over around 20 million years the ash and other material that the volcano itself was made of slowly eroded away so that the solid plug at its center is now revealed in the form of Morro Rock. Morro Rock is one of a series of nine total volcanic plugs that extend south from Morro Bay to San Luis Obispo. These are called the Nine Sisters.

Day one of the field seminar was a success. It may have been a day filled with a lot of travel, but we saw some very exciting things along the way. After Morro Bay, we headed to our hotel for the next couple of nights in Marina, CA. Some rest would prove to be quite needed, as we were in for a long day of research on day two of the trip.

By: Arik Arnevik

Day 2

Marina Beach State Park

The class awoke Sunday morning the 14th of October from our Best Western Hotel in Marina, California, about 160km (100 miles) south of San Francisco. Instructor Harry Jol on the other hand had been awake for some time before most everyone else, even enjoying a morning swim in the Pacific Ocean that was within short walking distance of the hotel. After a nice breakfast in the commons it was time to get down to business.

The first stop of the day was just a few hundred meters from the hotel. Harry sent the class over to inspect an area just off of the coast. This area, as the sign told us, was the Marina Dunes Preserve. As we walked toward the beach on the designated walking path, we could see large hills on either side of us running parallel to the path. These large continuous hills proved to be the sand dunes of the Marina Dune Preserve. The dunes were traveling perpendicular to the coastline, some for hundreds of meters. These dunes are of the coastal aeolian (wind-blown) variety. The sand supply from the beach accompanied with the winds blowing toward and away from the ocean, depending on the time of day, is what formed these dunes. The change in wind direction is due to the relatively rapid heating and cooling of the land surface as compared to the ocean. The dune surfaces were covered with, in some spots thicker than others, a plant known as Ice Plant. This plant was put there by humans in an attempt to stabilize (prevent erosion) them. As the dune approached the ocean, there was a point where there was a steep drop off. This drop off was due to the tides that roll in and erode the ends of the dunes. After investigating the Marina Dunes Preserve we walked over to a visitor’s parking lot to meet up with Mitch Craig and three of his students from California State University-East Bay for our research at Fort Ord.

Fort Ord State Park

The next stop for the day was Fort Ord Dunes State Park. The feature that we investigated at Fort Ord was the large (50m high) coastal dune that traveled parallel to the coastline at a distance of about 75m away. This dune was also covered with the Ice Plant that we saw at the Marina dunes earlier in the day which is used for stabilization. Another plant called European Beach Grass was also planted for stabilization. There was a major difference in this dune as compared to those seen in Marina. There were a series of concrete bunkers set into the side of this dune from the days of Fort Ord being a military post and target range. The dune was investigated with ground penetrating radar (GPR) and global positioning systems (GPS) for our research project as a class. More information about our research at Fort Ord can be viewed on the research page of this website.

Before the GPR and GPS research began, Arik Arnevic shared with the class his oral presentation on ground penetrating radar (GPR) and its role in investigating fault systems. More in depth information on GPR can be viewed through the link to the GPR poster on the research page of this website. Our day of research in the field ended just as the sun was setting. We even made it back to the hotel in time to finish the second half of the Packer game. The night was capped off with dinner in Monterey and a midnight drive through Pebble Beach golf course; a great ending for a great day.

By: Arik Arnevik

Day 3

Big Basin State Park

Day 4 of our trip put us in the car for most of the day. Even so, it was a great day to experience another sect of Californian culture and take some amazing pictures. We woke up in Best Western Beach Dunes Inn on the coast of Marina, CA. After having our morning cup, we packed our vehicles and hopped onto Highway 1 heading north. The morning fog forced us to get experienced with sub-mile visibility and California driving. This is thanks to coastal wind changes pulling fog towards the rapidly heating land.

Though this weather isn’t favored by commuters, the farmers take advantage of it. The climate in this area is well suited for temperate tree fruit and nut crops such as plums, prunes, olives and almonds. As we approached Santa Cruz, the landscape had begun to transition from agricultural fields to heavily wooded areas. We turned onto to Highway 9 heading north. At Boulder Creek, we split off to Big Basin Highway. By this time we were surrounded by enormous redwoods, beginning to dwarf the majority of trees we are used to seeing in Wisconsin. At around 930AM Pacific time we had arrived at Big Basin Redwoods State Park. Though running short on time, we had just enough to take some pictures of the absolutely stunning and monstrous Redwoods.

Returning back to coastal environments, we stopped in Half Moon Bay where we picked up groceries and other necessites. Some of us treated ourselves to coffee at Peet’s Coffee & Tea while others visited some local shops. We then continued up Highway 1 to our next stop at Devil's Slide. This is where Matt gave his presentation on earthquake induced landslides in California. We learned how the geology of a given region affects whether landslides will occur or not. Materials such as marine sedimentary rocks, volcanic soils containing clay, and alluvial deposits are generally most susceptible to landslides. Topography can also play a part in directing seismic waves generated from earthquakes. A combination of such factors led to the formation of Devil’s Slide.

After the presentation and a quick lunch, we continued up to San Francisco. There we picked up Eau Claire Alumni and University of Arizona Ph.D. student Phillip Larson. Phil offered his geology/geography knowledge throughout the remainder of the trip. The rest of the daylight was spent driving west towards Yosemite. We arrived at Yosemite National Park in the dark at roughly 9:00PM Pacific. Due to the overly friendly animal population in the park, we locked our aromatic food into steel boxes. Before retiring to our tarp shanties, we lit a campfire and discussed the remainder of our trip.

By: David L Simenson

Day 4

Yosemite National Park: Tunnel View and Glacier Point

Tuesday, October 16th, 2012 our group woke up in the Housekeeping Camp in the valley of Yosemite National Park and viewed Half Dome from the base. While walking along the Merced River, Phil Larson explained rock varnishing, the staining and streaking on the faces of the rocks of the area. Rock varnish is formed from various types of geologic and organic processes where visible streaking on the rock is due to iron and manganese being saturated in water. The water transports these minerals through the rock formation and out to the surface of canyon walls where it is visible as black streaks weeping down the face of Half Dome in Yosemite National Park. Additionally, a variety of microbes and fungi concentrate in these wet areas add to the darkness that streak down these canyon walls.

After packing up, our group drove up to Glacier Point where Phil Larson talked about the formation of Half Dome and the various other geologic processes that formed the areaincluding tectonics, glacial erosion and deposition, rock slides, hanging valleys, roche moutonnees, burnhardts, and spalling.

Approximately 210 million years ago Yosemite was a sedimentary landscape with the Merced River running through it carving out a v-shaped valley. Then about 130 million years ago, a period of dynamic tectonics and volcanism led to granite building creating a batholith. An ice age which produced glaciers allowed erosion to remove layers of sediment from above the batholith creating u-shaped valleys and relieving pressure on the granite batholith. The u-shaped valleys give proof to a period of glacial movement, because glaciers covered the area, moving through the v-shaped valley and carving out the valley, transforming this formation into a massive u-shaped valley that can be seen in the photo below. As the glaciers retreated, piles of rock debris were deposited throughout the valley.

As the pressure was relieved weak areas in the batholith began to pop creating spalling. The Royal Arches are a great example of spalling.

The theory of bornhardts was proposed that the roundness of the tops of the mountains were created by chemical and physical weathering over time. John Shaw proposed that these features were drumlins where glaciers had created these rounded tops of mountain peaks. It has since been revealed with the knowledge that the glaciers that formed this u- shaped valley did not in fact reach heights far enough up to have created these formations.

Before heading out on our very long drive to Death Valley, our group stopped at the Yosemite Village to visit the gift shops and other various stores and museums where we found an alumnus from the University of Wisconsin – Eau Claire working as a park ranger.

Mono Lake and Long Valley Caldera

Traveling along Highway 395 southbound, also known as the Tioga Pass (elevation 3031 m), from Yosemite National Park through to the Long Valley Caldera, cinder cones and resurgent domes were visible on both sides of the highway. Long Valley Caldera is located in the southwestern corner of Mono County on the east edge of California between the Sierra Nevada and White Mountains. At the Mobil gas station just before Mono Lake, Dr. Phil Larson talked about the formation of the Long Valley Caldera and the present deformation of the area.

Calderas are formed when a volcano experiences a large explosion or from a collapse of an empty magma chamber. The Long Valley Caldera has been experiencing episodes of unrest and deformation for about 760,000 years due to the volcanic activity below the surface. Many factors drive the increased activity of the resurgent dome, such as hydrothermal activity and partial melting of rock material below the surface. Many types of volcanic activity have erupted from the chain of volcanoes throughout the Mono-Inyo Craters that run through the western section of the caldera over the last few thousand years. Of these there have been two main type of volcanic activity in the Long Valley Caldera, pyroclastic and basaltic flows. The greatest determinate that distinguishes the two is silica content.

As we descended into the valley and elevation decreased the temperature noticeably increased. When we first entered Death Valley the temperature was around 23⁰ C, but as we reached elevations just meters above sea level temperatures rose to around 30⁰ C. Unfortunately, it was already dark when we entered Death Valley from the north, so we were unable to view Death Valley as we traveled through it. After traveling a better part of the day, we arrived at our hotel Stovepipe Wells in Death Valley very late in the evening. We ate dinner and readied ourselves for yet one last adventure of the evening. Everyone piled into vehicles and headed out to the sand dunes were we relaxed and enjoyed the unbelievable view of the stars above.

By: Jessica Stodola

Day 5

Death Valley National Park

Having arrived at night, we woke up to the land of extremes: Death Valley National Park. Death Valley is located at the beginning of the basin and range region of the southwest and is most notable as the hottest, driest and lowest location in North America. To most, this park may seem like a desolate piece of land, but Professor Jol and Phil Larson exposed us to an actively evolving environment of alluvial fans, former lake beds and dunes, expansive salt flats, borax mines and fluvial and erosional processes. With hydration and sunscreen as our number one priority, we explored this unique environment.

Our first stop was on the shores of Lake Manly. At the end of the Pleistocene era, roughly 10,000-12,000 years ago, Death Valley was home to massive freshwater lakes including Lake Manly. As the climate became hotter and drier, this lake dried up and left its remains of beaches and dunes. The same dune formations we examined in Zion and Fort Ord, were evident in this landscape as well. As Lake Manly dramatically dried up, the salt in the subsurface quickly came to the surface. Devil's Golf Course is a prime example of expansive salt deposition creating columns of jagged salt. The salt formations at Devil's Golf Course are a direct result of the extreme conditions. Because of the salt depositions, this area is the former home to borax mines. Borax provided a “gold rush” of Death Valley in the early 1900’s as borax became popular in the production of soaps.

We continued through Death Valley stopping at the Visitor’s Center, an oasis of water and green grass. We restocked on water and listened to Roy’s talk on pup fish, an endangered species in Death Valley. Pup fish have evolved and differentiated overtime creating entirely different species that have adapted to increasing temperatures and water with increasing salinity. From the Visitor’s Center, we came to our most extreme stop at Bad Water Basin, the lowest point in North America at 85.5 meters below sea level. Because of this elevation, water accumulation continues to occur in this location leaving salt deposits behind.

Racing the sunset, we came to a unique feature on the landscape: Mushroom Rock. The formation of Mushroom Rock is heavily debated. Some academics say the rock has formed from an abundance of sand particles weathering the rock through wind abrasion. Others argue that the rock was previously embedded in the subsurface and has eroded away by salt weathering. Having survived the incredible heat, we cooled down by climbing to an elevation of 1669 meters above sea level to Dante’s View. We took in the sunset and the incredible view of the expansive and unique landscape of Death Valley.

By: Meghan Kelly

Day 6

Zion National Park: Canyoneering

After a quick continental breakfast at the Best Western in Mesquite, NV we made our way to Springdale, Utah to begin our day of canyoneering the slot canyons just outside of Zion National Park. Our first stop after checking into the Bumbleberry Hotel was to pick up our gear and tour guides, Seth and Tanya, from the outfitting company Zion Rock and Mountain Guides. Once we grabbed our helmets and harnesses we were shuttled to our destination and instructed on how to put on our equipment nice and snug. After a quick hike down into the slots we stopped for a brief how-to session on rappelling.

Our first rappel was approximately 9.1 to 10.2 meters down. Once we all made it down safely we hiked a short distance through the slot until we arrived at our next and final rappel. Our second rappel was a little bit more intimidating at 27-30 meters down. After we walked a little further in we reached a slight elevation drop of about 2 meters. We were guided by Seth on how to shimmy our way down without the help of the ropes for assistance. Tanya then showed us all how to crab walk our way through the slot so as to avoid getting wet as there was some leftover water in the canyon from a previous rain. Not all of us were successful in staying dry but it was fun watching everyone’s different climbing techniques.

We continued on for roughly 400 meters to a small clearing where Harry stopped for a short seminar to explain the stratigraphy of the slot walls. Harry informed us that the walls of Zion where formed due to the extreme compaction and cementation of ancient sand dunes that once spread over the area.

After Harry’s presentation we looked for a good spot to stop to have a snack and to listen to Mary’s more in-depth presentation on the slot canyons and how through several orogenic movements, fluvial processes and because of the specific terrain of the area, slot canyons are created.

Once Mary was done we continued on our canyoneering adventure and learned first-hand what smearing was and how to accomplish climbing freestyle up what appears as a nearly vertical slab of rock. In smearing you are trying to use the whole of the sole of your shoe to stabilize yourself against the rock in order to climb up the face. Smearing can be insecure but with practice it enables a beginner to become better at climbing by putting the burden of the strain on the legs and feet instead of the arms and hands. It was a little bit scary at first but once we all got the hang of it we climbed up and out of the canyon at a pretty fast rate.

After a hot trudge back to the van we all got shuttled back to Zion Rock and Mountain Guides shop and piled into the vehicles to get back to the Bumbleberry Hotel to rest and clean up before Jessica’s presentation.

At 6:30pm we all reconvened behind the Bumbleberry Hotel to listen to Jessica’s talk about the effects of utility-scale solar developments on the Desert Tortoises habitat. The solar plants are being built to address the energy crisis but are an additional risk to the already threatened species. The desert is the most suitable location for solar plants. But roads must be built to have access to the solar plants and fences are built surrounding these plants. The roads and fences are barriers that impede the genetic make-up of the tortoises. The roads are also dangerous for the tortoise because they are attracted to the heat of the asphalt and road related deaths are the primary reason for the decline of the desert tortoise. Several conclusions were made to increase the populations, one being to build underground tunnels so the tortoises could safely travel from one side of the road to the other.

As the sun was setting we planned our next day’s adventure and headed out to grab a pizza at the Flying Monkey just a block down from the Bumbleberry Hotel.

By: Mary Tubbs Beaudette

Day 7

Zion National Park

The day started as it always does, to a beautiful view, packing, and breakfast. We headed out from the Bumbleberry Inn and made our way to Zion National Park. We were unable to drive through the park, so we took the bus that travels throughout the park, making various stops to check out the local scenery and learn about the processes that formed Zion.

The Zion National Park formed through a number of processes over millions of years. Depositional processes from ocean sediment and Aeolian processes formed the prominent Navajo and Kayenta Sandstone seen throughout the park. Uplift along the Hurricane Fault caused the landscape to shift upward 1200-2100 meters. This increased gradient caused the energy of the Virgin River to intensify increasing its erosional ability and its ability to transport large amounts of sediment. The intensity of the Virgin River can be seen by the large boulders strewn throughout the river and the banks.

Weeping Rock Trail had an amazing view. Spalling caused by erosional processes such as vegetation like algae, freeze/thaw processes of water, and mineral expansion were evident. Water running horizontally through the cracks in the rock precipitate out silica in the rock, create the crystallization of silica on the rock surfaces.

GPR Ridge

This site was a GPR dune research site for Dr. Jol. The sloping layers observed had very similar grain size and covered almost the entire study area, leading us to the conclusion this site was created by aeolian processes, not fluvial. What created these formations was hypothesized to be sand dunes and wind erosion, due to the well sorting of grain size, sloping layers, and minimal color difference.

Kaibab Overlook, Navajo Bridge, Marble Canyon

After leaving Zion National Park, we stopped at the Kaibab Overlook on Highway 89A. Looking at the Escalante, also known as the Grand Staircase, four formations of the Colorado Plateau could be seen. The cliffs seen in the distance top layer being the Pink Cliffs, the middle the White Cliffs, and the bottom the Vermillion Cliffs. We were standing on the Kaibab uplift.

We then stopped at the Navajo Bridge which crosses the Colorado River. We saw 6 California Condors, which are currently protected by the Endangered Species Act, were seen perched on the bridge and a nearby cliff. Each bird was tagged with a number: 02, 14, 30, 55, 73, and 83. The Navajo Bridge marks o the beginning of the Grand Canyon at Marble Canyon.

By: Jessica Stodola

Day 8

Grand Canyon National Park: Grand View Trail

We woke early the morning of the 20th in Best Western Grand Canyon Squire Inn, in the town of Tusayan. After a quick breakfast we prepared for the Grand Canyon hike. We filled water bottles and drove out to our hiking start point at Grandview Trailhead. A trip down the Grand Canyon requires a hefty 6 liters of water. Here our group met up with Dr. John Douglass and his group of students from Paradise Valley Community College. He has had extensive research in the area. Before our descent into the canyon, Douglass gave us a brief introduction as to how the Grand Canyon was formed. He discussed four theories explaining how the Colorado River cut through the Kaibab Plateau:

1.) Antecedence- The Colorado River cut through the Kaibab Plateau as it slowly uplifted into a monocline
2.) Superimposition- Weak sediment layers eroded, giving way to older layers once buried
3.) Stream Piracy- Another stream captured and diverted the headwaters of Colorodo
4.) Spill-over- The fourth theory is Douglass’s own. It is a process called overflow. It suggests that a lake as big as the current lake Michigan continued to be supplied by the Colorado. Eventually the lake flowed over. Coupled with monocline uplifting, the steep gradient quickly pushed the river through soft sediments and continued to carve the canyon over the next five million years.

With a basic understanding of those theories, at 10:00AM Pacific we started our way down Grandview Trail. The trail led down through different sediment layers all tinged red from the oxidation of iron. Three hours later, we came to Grandview Point. Here we ate lunch while Phillip Larson further explained John Douglass’s theory. Thereafter, our minds quickly turned towards the next big task at hand; getting back up the canyon.

Like the group of champions we are, we barreled up the side of the canyon. We stopped only to capture the scenery and swig some water. After three hours, we came to the top of the trail with an amazing sense of accomplishment. The euphoria combined with the spectacular late afternoon scenery made it all worth the work.

Directly after the hike, we drove to the Pizza House in Tusayan and feasted on the local cuisine. We closed out the day, recovering back at the Inn.

By: David L Simenson

Day 9

Meteor Crater, Sonoran Desert, Salt River Valley

After enjoying a gourmet continental breakfast at Best Western Premier Grand Canyon Squire Inn in Grand Canyon, AZ, we headed to Meteor Crater near Winslow, AZ. To start off our tour, we took a quick hike around the crater where we learned that there has been some significant controversy regarding the origin of the crater. Although this crater is not the oldest recorded impact site it is the best preserved site in the world. The crater was formed approximately 50,000 years ago when a meteorite, 150 feet wide, slammed into Earth traveling 26,000 mph. Scientists first suggested that Meteor Crater was the result of volcanism.

In the early 20th century Daniel Barringer, a mining entrepreneur looking to strike it rich by mining out the meteoric iron deposits proposed that the crater formed due to an impact of a large meteorite. It was not until the 1960's that Barringer's impact theory was finally received as doctrine due to the work of geologist Eugene Shoemaker. Creationists use the thrust fault on the crater's south rim to argue that geologists aging of stratigraphic layers are incorrect. The thrust fault was formed when the crater collided with Earth and flipped the rock layers upside down to put the oldest layer, the Coconino Sandstone formation on top. We also learned a fun fact that in 1964 a plane flying low over the crater was unable to get out of the crater and subsequently crashed; parts of the airplane still remain in the crater today and can be seen in the photo above.

After our hike, we toured the visitor’s center and reconvened in the parking lot to eat lunch and learn from Phil Larson about the San Francisco Volcano fields. After Phil's talk, Joe presented his research project on solar plants and informed us on why solar energy is a good option for the desert southwest.

The team also learned about biological soil crusts from Dave. Biological soil crusts are found in dry deserts and are important for the desert ecosystems because they take nitrogen out of the air and bring it into the soil where it is processed by other vegetation. They also retain water which is very important in areas with infrequent precipitation. Biological soil crusts help in soil stabilization and are very resistant to the desert heat. These crusts though are very fragile to human impacts. They are damaged by vehicles and footsteps very easily, so take care where you walk because these crusts are very much alive.

At Our next stop was the Sonoran Desert, Phil discussed his dissertation research regarding the Salt River Terrace layers. According to Phil's research the oldest layer called the Stewart Mountain Terrace is on top due to what is called lake overflow. This overflow would have occurred during the Pliocene. The Stewart Mountain Terrace rocks are related to the other floodplain layers in origin. They clearly belong to the Salt River sediment load but are significantly different in lithology. This research does not prove that lake overflow was the process that created this unusual layering but it is compatible with the lake overflow theory. We also learned that this area is continuously changing due to fluvial processes because pediments are not relic landforms.

We then stopped at Jackson's parents house for dinner. After a nice dinner and a relaxing sit under a perfect little lighted tree, it was Jackson's turn to present. Jackson presented information about alternative energy sources using bio-fuels converted from micro-algae. The argument presented was that fossil fuels greatly contribute to greenhouse gasses and this is a huge factor in global climate change. The use of soybean, corn and wheat to make fuel is also not the most efficient method due to the fact that these modes take up lots of land and drive food prices up because we also eat these plants. Algae only needs sunlight and water to grow and does not take up a huge amount of space. The biggest pitfall is that right now the process to convert micro-algae to bio-fuel using Photo Bio Reactors is quite costly. Convincing people that the benefits outweigh the costs is the on-going problem.

By: Mary Tubbs-Beaudette