Being an "older" geologist, I had always believed that the Tetons were due to basin-and-range extension. I thought the recent faulting responsible for the Tetons and the dramatic fault offset reflected mostly B&R activity. That changed about 10+ or so years ago when I came across the Yellowstone connection with John McPhee's CROSSING THE CRATON or a YouTube talk on Yellowstone/NW Wyoming geology. How I never considered the Yellowstone influence surprises me. JD Love had noted the evidence of sedimentary debris observed in the Gros Ventres that pointed to a topographic high in the eastern Snake River Plain that no longer existed and suggested that it had been due to the Yellowstone Hot Spot. The topographic high collapsing as the inflation moved further to the northeast. It's just a short jump to consider the Teton faulting might reflect the same mechanism.
As a side note, the gravels in the Gros Ventres were a target for possible placer gold when I was traipsing around this part of the country doing minerals exploration. Unfortunately, most of our field staff, including me, were victims of the early 1980's lay-offs and never got to test our hypothesis.
I am a retired geology prof, and I enjoy your posts very much, keeps me in touch at a time in my life when my wife quizzes my about the name of one of my favorite rocks, hornfels, just because I couldn't remember it one time. I got my undergraduate degree at MSU in the late 60's, so I am passingly familiar with much of what you post. I wanted to mention that I, as a USGS field assistant, climbed to the top of Mt. Moran just to inspect the thin bit of Flathead on top.
Interesting and well written article, thanks. So the eruptions produced plenty of CO2 at the time, but in the long term sequestered far more by natural carbon capture into the rocks. I like that happening over 2 million years is described as 'quick'!
Uplift due to the Yellowstone hotspot doesn't seem like it would provide enough long-term uplift to create the Tetons... Mountains like the Tetons would, I'd guess, 10's of millions of years to uplift, and the Yellowstone hotspot has been moving through the Snake River plain. Considering it hasn't been static, I find it potentially hard to believe Yellowstone could have uplifted the Tetons in such a short time. I would have thought more about Laramide Orogeny uplift than Yellowstone?
I’d say it certainly cannot be Laramide, because of the timing. I was generous in saying most of the movement on the Teton Fault was in the past 5-6 million years; some studies have suggested most of it is in the past 2 million years (https://www.researchgate.net/publication/215608428_The_Teton_fault_Wyoming_Topographic_signature_neotectonics_and_mechanisms_of_deformation) . Others (such as Smith & Siegel, Windows Into The Earth) suggest a heritage as old as 13 million years, still far too recent to be related to Laramide activity. I have not seen anything suggesting that the uplift of the Tetons and movement on the Teton fault is older than that, so yes, indeed, it has moved a lot, and quickly, in geological terms.
Also the Laramide deformation was predominantly compressional, and while you can certainly get extension within compressional systems, it’s still wrong for the timing.
I would be amazed if there is NO aspect of the Teton Fault that lacks any contribution from the basin and range extension, but the thermal bulge produced by the Yellowstone Hot Spot, and the cracking of the crust above it, seems to me to be the consensus primary driver for things like the Teton Fault as well as the similar but less spectacular Paradise Valley normal faulting north of Yellowstone. True basin and range extension seems to me to be mostly (but not entirely) dominant in the thin crust west of the Wasatch Front. Normal fault breaking within the Wyoming Craton, for example in Southwest Montana (Tobacco Roots, Ruby Range, Madison, and others), seems to exploit old Laramide basement uplifts by rejuvenation of the old thrusts in a normal sense. I don’t think there is any evidence that the Teton Fault follows an old Laramide structure, but the Camp Davis Formation, in Hoback Basin southeast of Jackson, does indeed seem to occupy a basin formed by rejuvenation of an older fault.
The timing of onset of Teton faulting, if something like 2.0 to 2.5 million is correct, fits excellently with the timing of the hot spot bulge when it was just west of the present-day Yellowstone Calderas, i.e. in far eastern Idaho.
The question is certainly not fully settled; in 2009 the J. of Volcanology and Geothermal Research published an entire special issue on “The Track of the Yellowstone Hotspot: What do Neotectonics, Climate Indicators, Volcanism, and Petrogenesis Reveal about Subsurface Processes?”
So I’m certainly not claiming to be the end-all expert of this, far from it; but I guess my reading and conversations with workers on the topic makes me believe that the thermal bulge, perhaps combined with some aspect of basin and range extension, is the driver behind the Teton Fault as well as the Paradise Valley to the north.
I really appreciate the super detailed answer! I’m surprised how unfamiliar I was with the Tetons having grown up in that area! I’ll have to check these resources out, especially the 2009 JVGR edition. I’m totally amazed how fast the uplift was then at the Tetons and how dramatic an effect Yellowstone has had. How active then are faults in the Tetons today? I don’t remember any significant earthquakes from there in my lifetime. I’d be surprised if that much uplift occurred in 2 million years and is now pretty entirely quiet. But, considering I didn’t know anything about their formation, I guess actually wouldn’t be that surprised!
I have the impression the Teton Fault itself is not very active seismically at present. Some studies have suggested that there was a pulse of activity in the 9,000 to 15,000 years ago time frame, a result of rebound due to glacial melting, but I don't recall their basis for that. The Hebgen Earthquake, 65 years ago next week, was the largest historical quake in the Northern Rockies, and just west of Yellowstone while the Teton Fault is just south of Yellowstone. I think the region, if not the Teton Fault per se, is considered one of the highest risk areas in the Intermountain Seismic Zone.
I did a quick search and it seems the recurrence interval is about 5,000 years for M6-7 events. Last was 5,900 years ago I think. I do remember studying the Hebgen event but I figured it was isolated from the Tetons. Seems like a high risk area, especially since there doesn’t seem to be any periodic earthquakes releasing energy and it is pretty highly locked. Very fascinating. I have so much reading to do now to learn more about the area. I’ve visited and been there so many times I can’t believe how little I know! Thanks so much for the discussion Richard!
I recently watched a presentation by Dr. Rob Thomas (University of Western Montana, the same Thomas referenced earlier) primarily on the Origin of geothermal features in Montana and Yellowstone Park. The last part of the talk discussed the high seismic hazard potential for NW Wyoming, Eastern Idaho, and SW Montana. It seems to be mostly unknown to many emergency response agencies and the general public. See https://www.youtube.com/watch?v=0pWqcf4qwQU&ab_channel=MontanaGeologywiththeRockDoctor
Thanks, Bob I’ll check this out. I know Yellowstone is incredibly seismically active with the hydrothermal circulation of groundwater and pulses of magma recharge. Earthquake swarms of >100 earthquakes are pretty common around the park. But I was less familiar with the general region’s seismic hazard. Thanks!
Being an "older" geologist, I had always believed that the Tetons were due to basin-and-range extension. I thought the recent faulting responsible for the Tetons and the dramatic fault offset reflected mostly B&R activity. That changed about 10+ or so years ago when I came across the Yellowstone connection with John McPhee's CROSSING THE CRATON or a YouTube talk on Yellowstone/NW Wyoming geology. How I never considered the Yellowstone influence surprises me. JD Love had noted the evidence of sedimentary debris observed in the Gros Ventres that pointed to a topographic high in the eastern Snake River Plain that no longer existed and suggested that it had been due to the Yellowstone Hot Spot. The topographic high collapsing as the inflation moved further to the northeast. It's just a short jump to consider the Teton faulting might reflect the same mechanism.
As a side note, the gravels in the Gros Ventres were a target for possible placer gold when I was traipsing around this part of the country doing minerals exploration. Unfortunately, most of our field staff, including me, were victims of the early 1980's lay-offs and never got to test our hypothesis.
A very "older" geologist if you were laid off in 1908 Bob 😁
Oops that should be 1980's. Typos, typos, typos I hate them.
I am a retired geology prof, and I enjoy your posts very much, keeps me in touch at a time in my life when my wife quizzes my about the name of one of my favorite rocks, hornfels, just because I couldn't remember it one time. I got my undergraduate degree at MSU in the late 60's, so I am passingly familiar with much of what you post. I wanted to mention that I, as a USGS field assistant, climbed to the top of Mt. Moran just to inspect the thin bit of Flathead on top.
Is lack of tectonic/volcanic activity connected with onset of snowball earth? Given that volcanoes produce lots of CO2?
It's been suggested that the Franklin Large Igneous Province in Canada might have had a role in Snowball Earth. https://www.science.org/content/article/massive-lava-outburst-may-have-led-snowball-earth
Interesting and well written article, thanks. So the eruptions produced plenty of CO2 at the time, but in the long term sequestered far more by natural carbon capture into the rocks. I like that happening over 2 million years is described as 'quick'!
Uplift due to the Yellowstone hotspot doesn't seem like it would provide enough long-term uplift to create the Tetons... Mountains like the Tetons would, I'd guess, 10's of millions of years to uplift, and the Yellowstone hotspot has been moving through the Snake River plain. Considering it hasn't been static, I find it potentially hard to believe Yellowstone could have uplifted the Tetons in such a short time. I would have thought more about Laramide Orogeny uplift than Yellowstone?
I’d say it certainly cannot be Laramide, because of the timing. I was generous in saying most of the movement on the Teton Fault was in the past 5-6 million years; some studies have suggested most of it is in the past 2 million years (https://www.researchgate.net/publication/215608428_The_Teton_fault_Wyoming_Topographic_signature_neotectonics_and_mechanisms_of_deformation) . Others (such as Smith & Siegel, Windows Into The Earth) suggest a heritage as old as 13 million years, still far too recent to be related to Laramide activity. I have not seen anything suggesting that the uplift of the Tetons and movement on the Teton fault is older than that, so yes, indeed, it has moved a lot, and quickly, in geological terms.
Also the Laramide deformation was predominantly compressional, and while you can certainly get extension within compressional systems, it’s still wrong for the timing.
I would be amazed if there is NO aspect of the Teton Fault that lacks any contribution from the basin and range extension, but the thermal bulge produced by the Yellowstone Hot Spot, and the cracking of the crust above it, seems to me to be the consensus primary driver for things like the Teton Fault as well as the similar but less spectacular Paradise Valley normal faulting north of Yellowstone. True basin and range extension seems to me to be mostly (but not entirely) dominant in the thin crust west of the Wasatch Front. Normal fault breaking within the Wyoming Craton, for example in Southwest Montana (Tobacco Roots, Ruby Range, Madison, and others), seems to exploit old Laramide basement uplifts by rejuvenation of the old thrusts in a normal sense. I don’t think there is any evidence that the Teton Fault follows an old Laramide structure, but the Camp Davis Formation, in Hoback Basin southeast of Jackson, does indeed seem to occupy a basin formed by rejuvenation of an older fault.
The timing of onset of Teton faulting, if something like 2.0 to 2.5 million is correct, fits excellently with the timing of the hot spot bulge when it was just west of the present-day Yellowstone Calderas, i.e. in far eastern Idaho.
Thomas and Sears (2020) show various lines of sedimentological evidence to support regional tectonism related to the thermal bulge, although they don’t discuss the Teton Range much except to suggest that there was essentially no significant topographic features in the northern Tetons/Jackson Hole until quite recently (less than 5 million years). https://www.researchgate.net/publication/346646075_MIDDLE_MIOCENE_THROUGH_PLIOCENE_SEDIMENTATION_AND_TECTONICS_IN_MONTANA_A_RECORD_OF_THE_OUTBREAK_AND_PASSAGE_OF_THE_YELLOWSTONE_HOTSPOT
The question is certainly not fully settled; in 2009 the J. of Volcanology and Geothermal Research published an entire special issue on “The Track of the Yellowstone Hotspot: What do Neotectonics, Climate Indicators, Volcanism, and Petrogenesis Reveal about Subsurface Processes?”
So I’m certainly not claiming to be the end-all expert of this, far from it; but I guess my reading and conversations with workers on the topic makes me believe that the thermal bulge, perhaps combined with some aspect of basin and range extension, is the driver behind the Teton Fault as well as the Paradise Valley to the north.
I really appreciate the super detailed answer! I’m surprised how unfamiliar I was with the Tetons having grown up in that area! I’ll have to check these resources out, especially the 2009 JVGR edition. I’m totally amazed how fast the uplift was then at the Tetons and how dramatic an effect Yellowstone has had. How active then are faults in the Tetons today? I don’t remember any significant earthquakes from there in my lifetime. I’d be surprised if that much uplift occurred in 2 million years and is now pretty entirely quiet. But, considering I didn’t know anything about their formation, I guess actually wouldn’t be that surprised!
I have the impression the Teton Fault itself is not very active seismically at present. Some studies have suggested that there was a pulse of activity in the 9,000 to 15,000 years ago time frame, a result of rebound due to glacial melting, but I don't recall their basis for that. The Hebgen Earthquake, 65 years ago next week, was the largest historical quake in the Northern Rockies, and just west of Yellowstone while the Teton Fault is just south of Yellowstone. I think the region, if not the Teton Fault per se, is considered one of the highest risk areas in the Intermountain Seismic Zone.
I did a quick search and it seems the recurrence interval is about 5,000 years for M6-7 events. Last was 5,900 years ago I think. I do remember studying the Hebgen event but I figured it was isolated from the Tetons. Seems like a high risk area, especially since there doesn’t seem to be any periodic earthquakes releasing energy and it is pretty highly locked. Very fascinating. I have so much reading to do now to learn more about the area. I’ve visited and been there so many times I can’t believe how little I know! Thanks so much for the discussion Richard!
I recently watched a presentation by Dr. Rob Thomas (University of Western Montana, the same Thomas referenced earlier) primarily on the Origin of geothermal features in Montana and Yellowstone Park. The last part of the talk discussed the high seismic hazard potential for NW Wyoming, Eastern Idaho, and SW Montana. It seems to be mostly unknown to many emergency response agencies and the general public. See https://www.youtube.com/watch?v=0pWqcf4qwQU&ab_channel=MontanaGeologywiththeRockDoctor
Thanks, Bob I’ll check this out. I know Yellowstone is incredibly seismically active with the hydrothermal circulation of groundwater and pulses of magma recharge. Earthquake swarms of >100 earthquakes are pretty common around the park. But I was less familiar with the general region’s seismic hazard. Thanks!
Very interesting, Dick. Wish I'd been up to speed with this info when I climbed Grand, Teewinot, and Moran back in the late 80s.
Jim Gruber