Into the Valley of Death (Part 3): Canyon Combing
No tour of Death Valley would be complete without a peek into the myriad of mysterious canyons that slice abruptly into the mountain ranges surrounding the valley. When rain does bless Death Valley, it often arrives quickly and in large quantities, which can quickly turn a storm from a blessing into a nightmare. With little soil and few plants to soak up the water, most precipitation ends up rapidly draining into creeks and streams. Canyons that are bone dry 99% of the year can almost instantaneously find themselves channeling deadly flash floods, mudflows, and debris flows. Each time this happens, the canyons get slightly deeper (and the mountains slightly smaller) as the water picks up and transports bits of rock down to the valley floor where it dumps them in large piles known as alluvial fans. If the mountains weren’t continually being uplifted by tectonic forces (which most of the ranges in Death Valley are), this process would quickly erase the mountains from the landscape.
In October 2015 (just a few months before our visit), portions of Death Valley received several inches of rain in just a few hours, a nearly unprecedented storm for such a dry environment. Many roads were damaged or wiped out completely by floods and debris flows and portions of the park remained closed even several months later.
One of the most interesting canyons in Death Valley is Gower Gulch, located just south of Furnace Creek. Until recently, Gower Gulch was a small, run-of-the-mill canyon carved into the soft, buff-colored badlands of the Furnace Creek Formation. Things took a dramatic turn in the 1940s when the waters of the nearby (and much larger) Furnace Creek Wash were deliberately diverted into Gower Gulch in an attempt to prevent them from flooding populated areas downstream. With the drainage area of Gower Gulch enlarged by over 16,000%, periodic floods began to incise Gower Gulch at an alarming rate. The Gulch has deepened by more than 20 feet in just the last several decades, an erosion rate nearly unheard of in the geological world. The rapid erosion rate has caused some unintended consequences to overlooks, roads, and other park infrastructure but has simultaneously provided geologists with a fascinating window into what happens when you make a stream too big for its own britches.
Gower Gulch had experience once of these erosive floods just a few months prior to our visit. The lower walls of the canyon were still coated in a thin layer of tan mud left behind by the October 2015 floods. In many cases, the mud line was 10-15 feet high. Little imagination was needed to realize that Gower Gulch would be a terrifying place to be during such an event!
An hour north of Gower Gulch is Mosaic Canyon. Cut into the Panamint Mountains the rise to the west of Death Valley, Mosaic Canyon also experiences mudflows and debris flows during intense rains. The bedrock of the canyon is ancient dolomites, limestones, and marbles; in many places, these rocks have been polished to a shine by floodwaters roaring through the canyon.
The highlight and namesake of the canyon though are the spectacular deposits of breccia (a sedimentary rock made of coarse-grained, angular rock chunks cemented together by a finer-grained matrix) that have been pasted onto the canyon walls by repeated debris flows. The high carbonate content of the rocks allows percolating water to quickly cement the debris flow deposits together into a solid layer that can adhere to the canyon walls. The fragments of rock within the breccia are a representative sample of those that comprise the Panamint Mountains, and thus vary widely in color making the breccia appear like a complex fresco created by a powerful force of nature.
One can hike up Mosaic Canyon (some moderate scrambling required) for about a mile and a half, admiring the rock formations, before coming to a ~50 high cliff (a waterfall during wet periods) that inhibits further upstream travel. Hiking up Mosaic Canyon is truly spectacular, each bend reveals a new assortment of geological treasures, only some of which are pictured here.
Into the Valley of Death (Part 2): Ventifacts and Dunes
Wind gets far more credit for shaping the surface of the Earth than it should. Contrary to popular belief, wind is a relatively poor sculptor of landscapes, especially when compared to water in its many forms.
Remove water from the equation though, and the influence of wind becomes magnified. The planet Mars is a great example. Dry for billions of years, with no streams or ocean waves to shape its landscape, Mars has become a barren land of sand dunes and sandblasted rocks.
If you want to experience a Mars-like landscape without the inconvenience of a long flight, Death Valley just might be your best bet. Here, water is so sparse that the effects of wind are more prominent and striking than anywhere I’ve ever visited.
My personal favorite wind-driven geologic phenomenon are what are geologists call “ventifacts.” Ventifacts are rocks (usually boulder-sized) that have essentially been sandblasted by wind-blown sand particles for extended periods of time. Ventifacts are consequently pockmarked with an array of pits, grooves, gouges, striations, and etchings that betray their uncomfortable past. Near Badwater in southern Death Valley, a low, linear ridge covered in boulders of dark black volcanic rock juts out into the valley, intercepting the strong winds that often blow along the valley’s length. Nearly every rock on this ridge shows these telltale signs of sandblasting. Combined with the lack of vegetation, photos from here resemble many of those taken by the Mars rovers more than just about anywhere else on Earth.
Larger ventifacts like the one below often take on an exceptionally strange shape. This is because wind (even very strong wind) is incapable of picking up anything bigger than a large grain of sand, and even then it can’t lift it more than a few feet off the ground. The result is that the bottom two or three feet of the bounder gets abraded away, while the top remains relatively intact, leading to the classic “hourglass” shape of large ventifacts.
All of the sand blown along the valley has to go somewhere. In several locations around Death Valley National Park, mountain ranges act as obstacles to wind, and where the wind stops or slows, the sand is deposited in large dune fields.
Death Valley has not shortage of dunes but the most accessible are the Mesquite Flat Dunes near Stovepipe Wells. Unfortunately, the proximity of these dunes to paved highways means that they are also one of the most visited locations in the park. Upon arrival at the dunes a bit before sunset, we were immediately greeted by the high-pitched insectile buzz of an amateur drone (currently prohibited in national parks) hovering overhead. Fortunately, such devices have a limited range and we were soon free of the annoyance. Even though the Sun was getting low, our plan was to stay awhile. Before long, the Sun set, the stars came out and we had the dunes almost entirely to ourselves as the nearly full Moon illuminated our path:
One unique feature of the these dunes is the presence of large patches of dried & cracked mud between the dune crests. Having been to dozens of different sand dunes, seeing anything other than sand (and the occasional hardy bush) in a field of sand dunes in a strange sight. The origin of the mud is connected to the fact that the dunes lie nestled against the base of the Panamint Mountains. Periodically, mudflows and debris flows burst forth from the canyons at the foot of these mountains, migrating their way into the low spots between the dunes. The mud dries quickly in the arid climate, forming the large mudcracks. The sand dunes, constantly in a state of motion, eventually bury most of the mudflow deposits, leaving only portions peeking through.
Coming up in part three, we leave the valley behind and explore the myriad of canyons cut into the mountains ringing Death Valley. Then it’s on to Joshua Tree!
Into the Valley of Death (Part 1)
Badwater Basin in Death Valley, the lowest (and hottest) point in North America at 282 feet below sea level, has long been on my list of places to visit in person. In part because of the superlative involved but also because Death Valley on the whole is a geological Mecca of sorts. A few weeks ago, I finally got to make my pilgrimage, but not without a few surprises. First of all, I never expected to be wearing four layers (including thermal underwear) and a winter hat when taking my picture next to the famous Badwater sign. I also didn’t expect visiting Badwater to be one of the least interesting things that I saw in Death Valley. This is not a knock against Badwater, but rather a testament to the fact that even after visiting 32 of the 59 national parks in the US, I can honestly say that Death Valley was one of the most spectacular and diverse I have been fortunate enough to spend time in.
With a week off before Christmas, we were looking for someplace “warm” to camp. We had originally planned to head to southern New Mexico and Texas to check out the Big Bend and Guadalupe Mountains area. However, in the days leading up to our departure, the forecast lows plunged into the low 20s. It wouldn’t kill us, but we figured we could do better. Heading to Death Valley turned out to be a good audible as the lows were only in the low to mid 40s, quite pleasant by December standards. Oddly enough it was a bad experience during the depths of winter in 1849-50 that gave Death Valley its foreboding name. One member of a lost and ragged group of prospectors is said to have quipped “goodbye Death Valley” as they finally departed the basin that had given them such torment. Today though, armed with an automobile and several large water jugs, winter is an ideal time to take in the spectacular sights of Death Valley. After several days in the park, saying “goodbye” was the last thing I wanted to do.
The first thing to know about Death Valley: it’s big. Nearly 3,000 square miles big. The national park that protects it and the surrounding mountains covers upwards of 3.3 million acres—about the size of Yellowstone and Grand Canyon National Parks combined—making it the largest national park in the U.S. outside of Alaska. It takes awhile to get around and the character of the valley varies wildly along its 100+ mile length. All parts of the valley share some common characteristics though: heat (average July high: 116.5 F), aridity (2.3 inches in a good year), and low elevation (over 500 square miles of the valley lie below sea level).
Death Valley has been low for a long time but the dryness is a comparatively recent development. During the last glacial maximum (geologist-speak for “ice age”) 12,000-30,000 years ago, the surrounding mountains received so much precipitation that Death Valley turned into an 100 mile-long lake known as Lake Manly. Since Death Valley is bordered on all sides by mountains, streams draining out of the mountains had no easy way out. Over time, as the climate dried and the lake evaporated, thick layers of salt were deposited on the valley bottom. This is why most of the valley floor appears white. With the encouragement of the rangers, I tasted it and can confirm that it is indeed salt!
In many locations (in particular a spot known as “Devil’s Golf Course”), the salt grows into some fantastical yet potentially dangerous formations. The valley here is a wonderland of 1-2 foot high irregular mounds of salt & mud, all encrusted with razor sharp blades and daggers made of salt crystals (see photos below). While the salt is relatively brittle, falls are still to be avoided at all cost. Walking around Devil’s Golf Course reminded me of the time I completed shredded a brand new pair of leather hiking boots in one week of doing geology field work on fresh, sharp a’a lava flows in Hawaii. The only difference was the a fall here would quite literally rub salt in your wound, not a pleasant thought at all.
Near Badwater Basin are some spectacular and very colorful badlands sculpted out of young, soft, clay-rich sedimentary rocks. We arrived in Death Valley our first day just in time to catch sunset over the badlands (photo at top of page) and then hiked through them the next day after we started to desiccate from walking around on the salt flats too much.
If salt daggers, ancient lakes, and badlands aren’t enough excitement for one day, you’ll be happy to know that the northern end of Death Valley has experienced some volcanic activity within the past few thousand years. In a stark contrast to the bleak white salt flats of the southern valley, the valley landscape here is shrouded in dark black cinders and volcanic cones. The centerpiece is a large hole known as Ubehebe Crater, a type of volcanic feature known as a “maar.” Maars are the result of “phreatomagmatic eruptions” (your new scrabble word for the day; it will just take you a few turns and some incredibly good luck to be able to play it…), which occur when magma beneath the Earth’s surface comes into contact with groundwater. The heat from the magma causes the groundwater to flash into steam, creating a violent explosion, and, as so often happens with violent explosions, a large hole in the ground. The red and white sedimentary rocks that existed prior to the eruption still appear beneath the volcanic cinders in places creating a beautiful palette of colors.
More photos of sand dunes, mountain canyons, and the spectacular geology of Death Valley to come!