Wild Ideas
Death Valley: Rock, rock, rock
While I was a huge rock hound at around age six, my interest in geology drifted away as I returned to my first love in nature, wildlife. That said, it’s hard not to be impressed by the geology at Death Valley National Park.
As I wrote about in my Oct. 28 column (exclusively online at rappnews.com/ wildideas), early in October I camped with my brother, Dana, and his wife, Joyce, at Death Valley, in the Mojave Desert of California. Temperatures were high for that time of year, especially where we camped, which was appropriately named Furnace Creek.
The other impressive feature of the park is its geology. The formations of rock that spell out the geologic history of this area are on full display there, with little vegetation in the way — from jagged peaks to shear cliffs showing layers of uplift and volcanic action over millennia, a golden canyon, pale mounds of borate minerals and salt and sand dunes. There are even boulders that mysteriously move around on the valley floor at what is called the Racetrack (tinyurl.com/wi-racetrack).
Dana met me in Las Vegas, where I had flown in, and during the almost three-hour drive back to the park, he talked about why
he and Joyce were surprised to find, over several visits, that the park was one of their favorite spots to camp. The quiet and the rugged geologic features were among their reasons, and I saw some of the latter when we stopped at Dante’s Peak, in the Black Mountains. It offers a spectacular view of the famous Badwater salt flats below and the Panamint Mountains beyond them (see the photo in the Oct. 28 column).
The park was definitely quiet . . . and dry — very, very dry — and hot. While I was there, the park was experiencing unseasonably high temperatures, in the upper 90s most days and topping out at 105 at Furnace Creek the day before I left. According to the park’s website, Death Valley is the “hottest, driest, and lowest national park” in the United States.
The heat and the fact
that I’d badly sprained my foot and ankle in a cat-wrangling accident the week before I arrived meant that I couldn’t do even the limited hiking we had planned to do. Instead of hiking, we toured the park using Dana and Joyce’s Eurovan camper and a rented Jeep.
The day after I arrived, my brother took me on the first tour, of Artist Drive, a dirt road that climbs to the top of an alluvial fan at the end of a deep canyon cut into the Black Mountains. An alluvial fan is “a more or less stratified deposit of gravel, sand, silt, clay, or other debris, moved by streams from higher to lower ground,” according to the U.S. Geological Service (geomaps.wr.usgs.gov/parks/deva/ftart1. html). The term “alluvial fan” came up frequently during the trip, perhaps because, in that mostly bare
landscape, it was easy to see this geological feature everywhere.
According to USGS, the stretch of the Black Mountains that Artist Drive goes through is called the Artist Drive Formation. It is made up of multicolored rock, most prominently along the section known as Artist’s Palette: “Aprons of pink, green, purple, brown, and black rock debris drape across the mountain front, providing some of the most scenic evidence of one of Death Valley’s most violently explosive volcanic periods.” The varying color came from oxidation and other environmental conditions during the tumultuous years the rock was formed and since, which acted on the exposed rock, making them different colors depending on their chemical makeup.
The tour of Artist Drive was short but offered some lovely views. Another outing in Death Valley, to Titus Canyon, offered more spectacular views of its geology and a few cliff-hanging thrills. Look for more about that in an upcoming column. © 2016 Pam Owen
FALL FOLIAGE FINALLY PEAKS IN RAPPAHANNOCK
Being away on vacation Oct. 5-15, I thought I’d miss peak fall color here. When I left, the leaves were just starting to turn in Rappahannock County, with the higher elevations of the Blue Ridge a week or so ahead. I was surprised, then, when I found the leaves still from peak color at the lower elevations when I got back. The foliage color there finally peaked last week, just in time for the Artists of Rappahannock Studio
& Gallery Tour last weekend (Nov. 5-6). Although by then many of the leaves had already been blown off the trees, the weekend still offered pretty much perfect fall weather and foliage for one of our favorite local events, and a big draw for tourists.
The lack of precipitation and warm weather in October may be a factor in when and how much leaves turned color this year, which results from a combination of sugars still being produced in the leaves while the plant is shutting down. Waning light is the main trigger for this process. The most brilliant colors come from a warm, wet spring, a seasonable summer without drought, and a fall that has warm, sunny days and cool nights.
Other signs of fall’s slow progress this year continue to appear around my house. While most wildflowers have finished blooming, a few evening primroses were still hanging in there after the weekend, and pairs of harvestmen (aka daddy longlegs) were still mating on the west exterior wall of my house. I’ve also been seeing lots of small orange-and-black butterflies, including pearl crescents, silvery checkerspots and somewhat larger meadow fritillaries, still active, and have gotten similar reports from some other residents who have also spotted them.
The lack of precipitation and warm weather in October may be a factor in when and how much leaves turned color this year.