Removal of the N. paleoTeton Range along the Yellowstone Hotspot Track: New Research and Insights
Вставка
- Опубліковано 15 жов 2024
- Dr. Ryan Thigpen University of Kentucky
In the northern Basin and Range, the margins of the relatively low-relief Snake River Plain, which marks the track of the Yellowstone hotspot, are surrounded by multiple high-relief (1.5 km) mountain ranges. These ranges, which are mostly composed of the uplifted footwalls of Basin and Range normal faults, are preserved both north and south of the denuded Snake River Plain. The simple geomorphic observation that mountain ranges do not exist along the track of the hotspot leads to the hypothesis that perhaps supercalderas completely “erase” or “remove” multiple mountain ranges, and by doing so, fundamentally reshape the topographic, fluvial, and climatic evolution of entire tectonic provinces.
In the early work addressing this hypothesis, our team used a technique known as thermochronology to constrain the timing and magnitude of cooling due to motion on the Teton fault and uplift of the Teton Range. This dataset was then integrated with fault modeling to demonstrate that the Teton fault, and by association, the Teton Range likely extended at least 40-50 km further north than the present-day topographic extent of the range, requiring that the topography be “removed” during migration of the Yellowstone caldera into its present position starting at ~2 Ma. In this talk, we will discuss insights gained over the last three years from: (1) 2-D uplift modeling of Teton fault evolution, (2) interpretation of LiDAR data along the fault system, including a recently available 2021 LiDAR dataset from Yellowstone National Park, (3) seismic reflection data acquired across modern fault scarps located between the Tetons and Yellowstone, and (4) new Jackson Lake seismic reflection data and long coring studies that bear on our understanding of modern Teton fault seismicity, including a potential first glimpse at the pre-Pinedale(?) earthquake history of the Teton fault.
Great talk. Thanks for the upload.
Very interesting as I watch this a year later. I always sort of wondered why the Tetons were such a short range, as far as N-S distance goes, yet so high and dramatic. And why they seem to so abruptly end just before Yellowstone. That 30 or 40% of the range got devoured by the YHS seems to make intuitive sense in light of these data and this study.
Someone asked where all the material from the old northern end of the Tetons went--did it go to the Snake River Plain, for example? I have always figured that it was melted into the Yellowstone cauldron down in or near the mantle and didn't go anywhere. Is that what most folks think? It was mentioned that because the basement rocks of the Tetons and rhyolites of Yellowstone have essentially the same chemistry, it would be hard to tell one from the other--if I understood the answer.
Question: Didn't the YHS also destroy the southern ends of the Lemhi and Lost River Ranges--and probably others--as it buzzsawed its way through Southern Idaho. Some think that those ranges, among others, ran south all the way to existing ranges in Nevada and Utah in the Basin and Range, pre Yellowstone hot spot.
Anyway, if so, I don't believe the Southern Lemhis or Lost Rivers are made of the same rock as the Tetons, or at least not all of them--there's a lot of limestones in parts of the Lemhis and Lost Rivers for example, along with slates and preCambiran Belt quartzites--a variety of stuff--but I never hear "granite" mentioned among them. So, if there was anything to find of those southern ranges now missing, would we be able to find evidence anywhere? Difficult I know, as much of the Snake River plain is now covered with much newer basalts from the much more recent rifting fizzures such as Craters of the Moon.
But still, I have always wondered whether you could find chuncks of those old mountain ranges embedded in the rhyolites of the older YSP exposures in Idaho. The fact that I have never heard of such a thing, at least yet, suggests to me that the YHS must melt and swallow everything that passes over it into its deep hot cauldron, never to be seen again, at lest in prior form.
Another question, or point I am always confused about. What is the relationship, if any, between the "migrating" YHS and Basin and Range extension? Did the B & R extension start before the arrival of the YHS? Or has the eastern boundary of the Basin and Range (i.e. the Tetons and the Wasatch today) always been just south of the YHS? Or is it a mere coincidence that the eastern edge of the Basin and Range and its fault systems going to Southern Utah happen to lie at the same longitude today as the YHS, but haven't in the past and won't in the future?
I have assumed that the movement of the YHS is the same speed as that which the North American plate slides west, and that the Great basin expansion is driven by the rifting of the Baja Peninsula away from North American continent, continuing into California and Nevada, whatever speed that is, which means the processes are independent of each other. But are they? I am not a geologist but have read what I can, and what I can digest, for many years now, and this question keeps coming up in my head.
Thank you for making these excellent presentations available to us thousands of miles away. I live in Puerto Vallarta Mexico now, at the base of the Sierra Madre del Sur batholith (which I wish I could find any videos or books about, geologically). But I spent part of my youth in the western shadow of the Tetons, on a farm I now learn was part of the Heise caldera of Old Yellowstone. Not many places on earth more breathtaking than the Tetons. Too bad if we lost half of them to Yellowstone's passing!
Amazing presentation! The Tetons have always been a passion of mine and your analysis is spot on. Thanks!
It would be interesting to see some sort of projection of future hotspot interactions with the topography -- maybe going forward 10 or 20Ma.
Probably similar to Nevada today.
@@12time12 - I think maybe considerably thicker crust will be over the hotspot in the future.
Uplift circa 20 MA is my guess; Columbia River Basalts magma building up under the Nevadaplano after the Yellowstone mantle plume burned through the subducting Farallon/Resurrection oceanic plate.
17 MA the flood basalts occur alongside rapid deformation of Nevadaplano leading to the basin and range province.
Further Teton uplift 10 MA occurs as the Yellowstone plume approaches, creating the range and volcanic plateau we all see today.
Awesome!
The data presentation is excellent. Yet, I still don't understand why Planetary Collision Dynamics with XL-Asteroids or Impact-phase Comets are not considered as a natural, reoccurring event that delivers more than enough adequate energy transfer levels to alter the surface of the Earth? Including cracking plates, moving/relocating, vaporizing millions of metric tons of crust & ejecta mirroring volcanic effects?
Active-phase & Impact-phase Comets atomize their chemical-elements, heavy-metals, rock, dust, etc., & smash into the Sun & planets at Mach > 30. Newton's, Gay-Lussac & Thermodynamic Laws will apply.
🤔🖖♻
Your going to need some evidence for this claim, no?
No. Apparently not .
@@topspintoo4703 OK, I guess at this point it's only a fairy story.
You did note that this is a hypothesis based on extensive modeling, LIDAR data, field research, thermochronology, fault modeling, long coring studies, and seismic reflection studies??? Did you read the attached introduction?
@@geologistsofjacksonhole1148 Should I infer that a significant element of guessing is involved with respect to and arriving at your hypothesis? Thank you.
@@christopherskipp1525so, what is your proposal as to why this lacks sufficient evidence? This methodology has been used in other locations.