For spring break, I went on a road trip to Death Valley, CA to… get my mind off my research I think? Well, as luck would have it, it’s a really inspiring place for its geology and geomorphology, and not such a good place for forgetting about all that. Armed with the book “Geology of Death Valley National Park” I set out to explore the geology of this fabulous place. Here’s a few of my favorite highlights.
Firstly, there are the faults and folds. They are pretty much everywhere. Death Valley is slowly pulling apart along a east-west trajectory due to extensional tectonics (i.e. it is being pulled apart like silly putty). As a result of this pulling, the valley basins are dropping and the mountain ranges are dominated by normal faults (great video here). You won’t just see normal faults, though. There definitely a few thrust faults around (Photo 1), resulting from compression, as well as every other type of fault or fold you could think of.
You can find evidence of the fault zones in non-mountainous features as well. The bases of the mountain ranges are almost all dominated by massive, spreading alluvial fans. Because these alluvial fans cross the fronts of the mountain ranges, they often cross the fault boundaries themselves! A lot of the fans show evidence of uplift along the fault lines with elevated shelves, or active fault traces. You will notice these as you drive along Badwater Road south of Furnace Creek (Photo 2). This particular shot is from the Badwater Spring parking lot (Awesome Map 1).
Well, right now I can only imagine that you are thinking “Uplifted alluvial fans! It doesn’t get any more exciting than that!”. Normally, I would agree. But if you keep driving south on Badwater Road, around mile marker 41 you will pass some UPLIFTED LAVA FLOWS! Now, if there is one thing even geomorphologists and geologists can agree on, it’s that lava is the coolest thing in the world. In this, geomorphologists feel very magma-nimous towards geologists.
Well, this is all pretty uplifting, you might say, but after awhile this faulting must get so normal. Well, you are laterally right (… groan)! There is a right-lateral fault in Badwater basin. If you want to see it for yourself, and not take my second-hand word for it, go check it out! It goes right through a cinder cone, pulling it in half (Photo 3)! You can see this awesome fault-action on the west side of the basin from Badwater Road, just north of Shoreline Butte (there are signs), and just opposite the lava flows around mile marker 41. I made a really sophisticated map (Awesome Map 2), because I am sure you are now planning your vacation
One more cool feature you might not notice unless you have had the fortitude to keep reading this blog (or bought a book, I guess), is evidence of liquefaction on the alluvial fan near Badwater Springs. Liquefaction occurs when the ground shakes during an earthquake. In this particular alluvial fan, the result is a series of strange, deep channels that run perpendicular to the alluvial fan.
Well, by now you are probably like “wow, southern Death Valley along Badwater Road sounds amazingly epic! Let me book some personal time and go take a vacation there right now!”. Well, you should definitely do that. But we’re not done yet! If you thought cinder cones being ripped apart was cool, what about cinder cones being BLOWN UP! Ubehebe crater (Photo 5) is a major attraction in the north of the park, close to the Racetrack (which, btw, you need 4WD to get to so go prepared, unlike me!). You don’t need 4WD to get to Ubehebe though. It might seem like just a quick stop, but it’s AMAZING and you could hike around for hours being constantly amazed, so get ready to spend a whole amazing day there. Did I mention it’s amazing? Ubehebe erupted most recently at least 800 years ago. The crater is called a maars, and formed when groundwater, heated by rising magma, exploded and punched a massive crater through an alluvial fan. You can very clearly see the distinction between the old alluvium, and the explosion related volcanic deposits (Photo 5).
Ubehebe isn’t alone out there, though, which is good because then it might have an uber-heavy heart. There are a couple of other maars around, and if you go for a walk through the surrounding moonscape, you will see a few others, like Little Hebe Crater (Photo 6).
Well, there are lots more geologic features to view in Death Valley National Park, but this blog post is already very long and frankly I am not a geologist, so let’s switch gears and keep this moving. In addition to seeing some cool geologic landforms, you will also see some very cool minerals in Death Valley. Most obvious are the salt formations which form from evaporated surface water in the valley bottom. Badwater Springs parking lot is the most popular place to see them, but frankly it was very busy and you can see them almost anywhere on the valley floor.
If you though salt formations were cool, then you will DEFINITELY want to make a trip north of the park to Mono Lake, close to Mammoth Lake. At Mono Lake, underwater springs lead to calcium deposits that form other-wordly limestone formations called tufa (Photo 8). It wouldn’t be that cool of a visit, but water diversions for rapid urbanization have led to severe drops in lake levels exposing the tufa, and now, with bittersweet irony, it’s a really cool place to walk around.
Right on the road to the South Tufa at Mono Lake (just south of the town of Lee Vining) you will see a little hiking sign to Panum Crater. It might not look like much, but GO HIKE IT! It’s really cool!!
Panum crater is really young, and because of that you can still find the (geologically) young rock obsidian. To widen the appeal of this post, let me go ahead and say that in the Game Of Thrones universe, obsidian is what is called ‘dragon glass‘, and it is the ONLY THING THAT CAN KILL ONE OF THE ‘OTHERS’! Ok, let’s all pretend that I didn’t write that and you didn’t just read that and know exactly what I’m talking about. We are too cool for that kind of thing. Anyways, in the ‘real world’ obsidian is just a really cool, shiny black rock that definitely can’t kill the undead, although admittedly I have never tried. At Panum crater, you can find obsidian in abundance, enough to arm your whole army (Photo 10)!!! I mean… absolutely no reference to GOT.
If shiny black glass rocks are not your thing, you can also find scratchy, dull, pumice stones (Photo 11). I mean dull as in the colour and the texture, not dull as in boring, because what could possibly be boring about a really low density volcanic rock?!?