Broken Basalt and Fractured Faults of Lava Beds National Monument, California

[@SkepticalRaptor]

I spent a week camping there in the middle of the Pandemic. I loved exploring the various caves and hiking up to a couple of the cinder cones. It’s an amazing place that’s not crowded. And it stays cool even in summer.

[@rogercotman1314]

Nicely explained, thanks Shawn. 97 like............ Another amazing area full of Geology issues.

[@mustangmorris53]

Always enjoy your videos .

[@shawnwillsey]

Glad you like them!

[@shawnwillsey]

You can support my field videos by clicking on the "Thanks" button just above (right of Like button) or by going here: www.paypal.com/donate/?hosted_button_id=EWUSLG3GBS5W8

[@Me97202]

I’ve been there many times…and still learned *a lot* from this video. Thank you.

[@marymachunis3778]

Another learning experience with this video. Thanks for all that you do.

[@stevengeorge5605]

Cool! Thanks Shawn!😀

[@maurasmith-mitsky762]

Thanks!

[@shawnwillsey]

Much appreciated. Glad you are enjoying these.

[@AKUSUXs]

Beautiful. Thanks for all the work you do. 👍👌😁

[@shawnwillsey]

Thank you! Cheers!

[@patroberts5449]

I think that little ant was very interested………

[@56NeilWatson]

Thanks for that Shawn. I cannot get my head around the fact that lava flowed for over 3 miles.

[@shawnwillsey]

That's nothing. There are flows here in Idaho that traveled 20+ miles. Then there's the Columbia River lavas that flowed hundreds of miles.

[@filonin2]

Wait until you learn about flood basalts.

[@3xHermes]

Perfect example of Basin and Range!

[@trevorwhat]

Great stuff, Shawn. Thanks for putting it together. I suppose similar tectonic drama with Abert Rim. Winter Rim. Warner/Hart Rim, etc.

[@Jack-ne8vm]

Nice logical explanation.

[@shawnwillsey]

Thanks!

[@bravendyer9529]

Thanks 🙏

[@ziggstah5307]

Thats a really cool area Prof . not only for the geology but the History hidden in there . Did you walk thru the MODOC standoff site? Its amazing and sad all at the same time....

[@shawnwillsey]

Captain Jack's Stronghold? Yes. And I did a video there since the geology and history are intertwined. Look for that one in the coming weeks. Amazing area.

[@christinedaly2694]

That was very interesting thank you

[@bagoquarks]

By zooming out from your location on Google Maps we can see that this is near the SE edge of the Cascades and the W edge of the huge Basin and Range territory. May we assume that we are, therefore, at the SE corner of the subducted Juan de Fuca plate, perhaps plunging very steeply beneath your video location?

[@Gizathecat2]

I hope he answers that very good question. Maybe Nick Zentner could discuss this.

[@shawnwillsey]

Good question. Possibly. Seismic tomography would be helpful to answer this question. Lava Beds volcanism appears to be mainly driven by extension. The Juan de Fuca plate is undoubtedly down there but at Lava Beds the subducted slab is too deep to trigger melting of overlying asthenosphere by dewatering of slab. Hence, the dewatering and subduction magmatism is westward near Mt Shasta and Cascade arc. Hope this helps.

[@bagoquarks]

@@shawnwillsey Yes, it does help. I had not heard the term "dewatering" before. In my mind I was using the clumsy "cooking off seawater."

[@daveanderson718]

Drove through there just last week. Did I pass you?

[@shawnwillsey]

Nope. I was there last week of August. Just backed up on videos I need to post.

[@jeffreyduplessis]

Do you have an explanation as to why the inter mountain west is undergoing extensional faulting? Based on the information I can find this faulting could be a result of stresses caused during accretion land forming during subduction of the Farallon Plate. Thanks!

[@mattcauthers1758]

So the lava that we were looking at flowed from south of this location? So when the crust stretches east and west how does it uplift and drop down at the same time? So the youngest lava flows are only 12,000 years old?

[@shawnwillsey]

Yes, the younger lava in the valley flowed north from vent at Fleener Chimneys. I believe the Devils Homestead is the youngest flow at Lava Beds National Monument but there are likely younger ones in the region.

[@johnnash5118]

The 2MA flood basalts are probably matched via the B&R normal fault under the 12.5KA flow. Could the flood basalts be a young episode of the Steens FB’s?

[@shawnwillsey]

I think these are too far east and too young to be directly associated with Steens basalt.

[@johnnash5118]

@@shawnwillsey My speculative question was based on the documention of 1- The Western extent of the Steens Flood Basalts are bordered by the Warner escarpment in NoCal., which is also the East margin of the Modoc Plateau. 2- The Modoc Plateau is a mile thick basalt province dating back to @25Ma, which would coincide with the location of the YHS beautifully. 3- the CFB Province erupted East to West away from the YHS track, and the youngest was the furthest from the YHS in Central WA. @5-6Ma, so would a dike swarm in NoCal be any less likely? Perhaps there may be tholeiitic- calc-alkalic problems that may separate the two provinces, but there’s still a lot of professional guesswork at play here.

[@lauram9478]

❤

[@jerryofsanfrancisco]

A friend insists that lava beds are only found in calderas. I disagree. I would appreciate your authoritative answer to this question. Best regards, JR (I think this video probably answers my question)

[@shawnwillsey]

Lava beds (probably more accurate called "lava fields" or "volcanic fields") can be found in a variety of settings. Anywhere there are sufficient expanses of lava (usually basaltic), this term could apply. I think it would also mainly be applied to fairly recent lava eruptions. Craters of the Moon comes to mind as one. The vast fields on the SE slope of Kilauea is another. Calderas are collapse features, often associated with explosive eruptions that do not involve basalt.

[@jerryofsanfrancisco]

thanks for taking the time to reply!@@shawnwillsey

[@GregInEastTennessee]

Looks like COTM. Are they similar? Are they both caused by thinning caused by basin and range expansion?

[@Mistydazzle]

What is COTM? Nevermind, I figured out it's Craters of the Moon. 🙂

[@shawnwillsey]

Similar composition and ultimately similar process of magma generation due to crustal thinning.

[@hypercomms2001]

As a suggestion, might be helpful to provide the google maps reference of the location that one is referencing...

[@shawnwillsey]

My videos have a Google Earth fly in and I list the GPS coordinates. Is that not adequate?

[@hypercomms2001]

@@shawnwillsey Thank you, I hope you do not mind, but would you be able to put the GPS co-ordinates in your summary notes... because that way it would be easier to simply copy and paste them into a browser to see the location ?

[@stephenwhitaker4491]

In my next life, I want to know what Shawn Willsey knows.

[@shawnwillsey]

Ha! Me too.

[@bravendyer9529]

Thanks!

[@shawnwillsey]

Thank you.