Saturday, April 6, 2019

Tales from the Semi-Super-Bloom Tour, Part 1: The Mojave Desert and El Paso Mountains

A lot of excitement has been generated this year with the plentiful precipitation in the California Desert and the resulting "Super-Bloom". Mrs. Geotripper and I didn't want to totally miss out on the sights, but we didn't want to be in the midst of crowds that we knew would be present in the places in the news like Anza Borrego or Lake Elsinore. So we zeroed in on the part of the California desert that hasn't been in the news: the Owens Valley and Death Valley National Park.
We knew from the start that we might not see a great many flowers because most of the storms had tracked more to the south, but there had still been considerable precipitation, just a bit later than other parts of the desert. So with proper expectations in place, we set out on the road a week ago. The nice thing about low expectations is that you have a good chance to be pleasantly surprised, and we were. It wasn't the 'super-bloom', but it was colorful enough, so we dubbed our journey the "Semi-Super-Bloom Tour".
 The first place that made us pull over was a non-descript road junction on Highway 14 near Jawbone Canyon and the El Paso Mountains in the Mojave Desert. There were lots of small flowers on the desert floor, including Goldfields, Phacelia, Mallows and small Lilies (I welcome and expect corrections on flower identification).
The desert floor where we were traveling has been largely given over to utilitarian uses. In the immediate vicinity there are airports, military bases, and solar arrays, as well as the towns of California City and Mojave. There isn't much wilderness in this part of the desert.
The landscape is geologically interesting, as we were paralleling the Garlock fault, which divides the Mojave Desert from the Sierra Nevada and the Basin and Range Province. The fault is active, with forty miles of left-lateral offset, but it hasn't produced any historical earthquakes of consequence. The potential certainly exists.

Although the fault motion is primarily lateral, some warping and deformation has lifted a mountain range on the north side of the fault, the El Paso Mountains. The mountains are composed largely of older Paleozoic metamorphic rocks. The rocks had been quite deep in the crust, but were brought to the surface and eroded, and by around 12-15 million years ago had been eroded to a fairly flat surface. This surface was eventually covered by terrestrial sediments deposited in alluvial fans, grassy plains and ephemeral lakes that would remind a person of the African savannah. The comparison is apt, because the sediments contain fossils of a diverse fauna that included ancient camels, horses, antelope, elephants, and a number of predators including to the forerunners to our modern cats and canines.
The valley floor where we stopped certainly had flowers, but we could see that a real super-bloom was underway on the slopes of the El Paso Mountains off to the north. The usually dull gray slopes were covered in places with a veritable rainbow of flowers that must have including a great many poppies and lupines.

Our highway turned north, crossed the Garlock fault, and entered Red Rock Canyon State Park, which preserves the Neogene sediments containing the fossils mentioned above. Millions of people have seen Red Rock Canyon, but not necessarily in person. The brightly colored cliffs have been used as the backdrop for hundreds of Hollywood movies (they were the cliffs of 'Snakewater', Montana in the opening scenes of the original Jurassic Park).

We found that many of the Joshua Trees were blooming. The trees are a defining characteristic of the Mojave Desert and are found primarily in east California and portions of Arizona and Nevada. The trees are a potential victim of global warming. Their seeds once were spread in the scat of giant ground sloths during the last ice age, but the sloths are gone, and with the increasing heat, the trees (actually lilies) are unable to propagate up slopes where they can thrive. Ironically, the trees may disappear entirely in the national park that is named after them.
We left Red Rock Canyon and headed north on Highway 395 towards our turnoff to Death Valley at Owens Lake. Along the way we could see that the "foothills" of the Sierra Nevada were also bathed in color. We were headed to Fossil Falls and Red Hill, hoping to see what had changed in the six weeks since we were last there. That will be the subject of our next post...


Andrew Alden, Oakland Geology blog said...

I'll be doing much the same trip next week. Thanks for the preview!

Hollis said...

Super enough for me :) Pretty neat to see those colors on such a dry-looking slope (El Paso Mts).