After a week of work in California, my coworkers and I spent the first part of our day off visiting Death Valley National Park. From there we continued our whirlwind Mojave Desert tour through Mojave National Preserve. We limited ourselves to a drive down the west side of the park on Kelbaker Road, but even this portion was pretty amazing.
The first features that jumped out at me were the cinder cone volcanoes near the northwest corner of the park.
The basaltic magma that formed these volcanoes had low viscosity and flowed freely. The cinder cones formed in the early stages of eruption. Initially the magma had higher gas content, and early on it sprayed into the air like a fountain. These small bits of molten rock cooled quickly and collected around the vents, creating these cones of accumulated scoria cinders. Later in the eruptions the gas became depleted. At this point large amounts of runny lava burst from the base of the cinder cones, flowed for great distances, and left behind the lava beds of black basalt seen today.
Not far down the road we got our first glimpse of a Joshua tree (Yucca brevifolia, Asparagaceae):
Although we would see a lot more of these later at Joshua Tree National Park, there were still quite a few to be seen here. These impressively tall yuccas are found almost exclusively in the Mojave Desert:
Further south we caught our first view of Kelso Dunes, part of the Devil’s Playground:
This is the largest field of sand dunes in the Mojave Desert, and some of the dunes exceed 600 feet in height.
The sand here originated from the erosion of the granitic San Bernardino Mountains to the west. Wind carried the sand eastward until it reached a trap between the Providence and Granite Mountains, where the wind slowed and dropped its sand load.
Plants eventually took hold in the dunes, locking them in place. New sand is still being deposited to the northwest, but in this area the dunes are now relatively static.
As we exited the south side of the park, we passed by some spheroidally-weathered granite near the Granite Mountains:
Throughout the park there were signs warning to watch for desert tortoises (Gopherus spp., Testudinidae) crossing the road. Although we looked around quite a bit for these interesting creatures, none were to be found. They spend most of their days in underground burrows, coming out only to feed, defecate, and in the late winter, to breed. Although we didn’t see the tortoises themselves, we did find many of their burrows and piles of feces. I would love to return to this national preserve to again try to find these elusive animals, as well as further explore the lava beds and eastern reaches of the park.