The Mystery of Upheaval Dome: Uniformitarian Impact Craters, Part Quatre

Guest 7,043 word essay by David Middleton

In my previous three posts on uniformitarian impact craters, we examined the pitfalls of drawing cartoons on Google Earth images without ever looking at the geology; how the Carolina Bays are as antithetical to impact features as any dents in the ground possibly could be; and poked a big hole in the latest Younger Dryas impact paper.

In part quatre (four for those who don’t pretend to speak French), we will look at Upheaval Dome in Canyonlands National Park, Utah… a supposedly confirmed impact crater.  In particular, we will examine how the world’s leading experts in impact craters and salt tectonics drew diametrically opposing conclusions from the same data.  This is rather long post, with a lot of geology jargon. If you aren’t interested in geology, you probably shouldn’t read any further.  I have included a glossary of geological terms at the end of the post… At least one of the definitions I found online exactly matched my 1976 copy of the AGI’s Dictionary of Geological Terms… What are the odds of that happening?

updome1

Figure 1. Aerial view of Upheaval Dome. Utah Geological Survey.

Upheaval Dome is a very enigmatic geological feature in Canyonlands National Park, Utah.  Since it was first described in 1927, several hypotheses have been put forward to explain its origin:

  • underlying salt dome
  • pinched-off salt diapir
  • cryptovolcanic explosion
  • fluid escape
  • meteoritic impact
  • and my personal favorite…

Over the years, all but two of these hypotheses have been shot down.

Pinched-off salt diapir or impact crater?

GEOSIGHTS: UTAH’S BELLY BUTTON, UPHEAVAL DOME

By William Case

Upheaval Dome in Canyonlands National Park, Utah, is a colorful circular “belly button,” unique among the broad mesas and deep canyons of the Colorado Plateau.

The rim of Upheaval Dome is 3 miles across and over 1000 feet above the core floor. The central peak in the core is 3000 feet in diameter and rises 750 feet from the floor.

Since the late 1990s, the origin of the Upheaval Dome structure has been considered to be either a pinched-off salt dome or a complex meteorite impact crater; in other words the “belly button” is either an “outie” (dome) or “innie” (crater).

Both origin hypotheses account for the overall structure of Upheaval Dome, assuming approximately a mile of overlying rock has been eroded. The main differences between the two hypotheses are the amount of time and the pressures needed to produce the structure.

A salt dome is produced when a subsurface layer of salt (originally deposited when a large body of saline water evaporated) is eventually squeezed upward because of the weight of overlying rock. At Upheaval Dome, the upward flow would have to have been “pinched off” by rock that fell into voids left by salt dissolved by surface water.

The pinched-off salt dome hypothesis assumes that up to 20 million years of moderate pressures produced the feature, compared to only a few minutes of extremely high to low pressure changes for the impact crater hypothesis.

Until recently, “smoking gun” evidence for either origin was absent because of erosion. No remnant pieces of salt or related rocks and minerals have been found to support the pinched-off salt dome hypothesis; neither were formerly molten rocks, ejected and crushed rock, or minerals altered by high pressure found to support the impact crater hypothesis.

Then, in 2007, German scientists Elmar Buchner and Thomas Kenkmann reported finding quartz crystals that were “shocked” by the high pressure of a meteorite impact. Many geologist now consider the mystery of Upheaval Dome’s origin to be solved (and it’s an “innie”!).

The core consists of the oldest rock formations at Upheaval Dome. The Organ Rock Shale and White Rim Sandstone of the Permian Cutler Group, and Triassic Moenkopi Formation were injected and pushed upward in a chaotic jumble. The Triassic Chinle Formation, Triassic-Jurassic Wingate Sandstone, and Jurassic Kayenta Formation and Navajo Sandstone are stacked, oldest to youngest, from the core to the rim.

[…]

Utah Geological Survey

Regional Setting

UHD_1

Figure 2. Schematic cross section of the Canyonlands National Park area.  The Paradox Salt Formation is the manila colored bulge underlying Canyonlands NP.  Upheaval Dome is out of the plane of the cross section, between Stillwater Canyon and Grandview Point. Capitol Reef Geological Cross Section, Capitol Reef Natural History Association.

UHD_2

Figure 3.  Canyonlands NP Stratigraphic Column.  Capitol Reef Natural History Association and Utah Geological Survey.

Canyonlands National Park and the entire Colorado Plateau are a “geologist’s paradise.”

From 2004-2007, we made several “field trips” to the region.  Upheaval Dome is almost dizzying.  These are some photos Mrs. Middleton (a fellow geo) took in 2007:

IMG_0159 140IMG_0150 131

IMG_0155 136

Figures 4, 5 & 6.  Photos of Upheaval Dome by Mrs. Middleton.

Can you believe that we forgot to include a lens cap for scale?

The light colored, greenish rock in the central part of the dome is the highly deformed Lower Triassic Moenkopi Formation.

UHD_3

Figure 7.  Upheaval Dome.  Utah Geological Survey.

Salt domes and impact craters are often surrounded by rim synclines.

Figure 8.  Examples of rim synclines. Cramez 2006.

Upheaval Dome has a rim syncline, surrounded by a rim monocline.  Salt domes often exhibit rim monoclines, impact craters don’t.

UHD_8

Figure 9.  Dome Encircling Monocline (DEM) = Rim Monocline or Ring Monocline.  Dome Encircling Syncline (DES) = Rim Syncline or Ring Syncline.  Geesaman 2015.

UHD_9

Figure 11.  Northern Paradox Basin Stratigraphic Column.  Geesaman 2015.

Upheaval Dome and Barringer Crater

The Colorado Plateau is also the host to one of the world’s most well-preserved and extensively studied impact features: Barringer Crater.  For a tremendous reference on Barringer Crater, I highly recommend David Kring’s Guidebook to the Geology of Barringer Meteorite Crater, Arizona (a.k.a. Meteor Crater).  

Barringer Crater is well-worth the price of admission.  While not as dizzying as Upheaval Dome, it is very impressive.

Meteor Crater_Arizona

Figure 12.  Barringer Crater (aka Meteor Crater), Arizona.  Photo by Mrs. Middleton.

Once again… We forgot to use a lens cap for scale… D’oh!

Barringer Crater is a “simple” impact crater.  If Upheaval Dome was an impact crater, it would be a “complex” crater.

simple-a-and-complex-b-crater-structure-credit-nasa

Figure 13.  Simple vs. complex impact craters. Brunetti 2014, original image from NASA.

About 145 million years of erosion has removed about 1 km of rock thickness from Upheaval Dome.  So the melt layers, impact breccia, ejecta fields and most other potential evidence for a meteoric impact are long-gone.  The highly deformed central uplift is assumed to be a remnant rebound feature of a complex crater.   On the other hand, the Barringer Crater impact occurred only 40-50 thousand years ago.  It is a nearly intact simple crater.

Here’s how the two geologic features compare:

Crater_map

Figure 14.  Geologic maps of Upheaval Dome and Barringer Crater plotted at the same scale.

Crater_xsect

Figure 15.  Cross sections of Upheaval Dome (Geesamen et al., 2015) and Barringer Crater (Roddy et al., 1975). Plotted at the same scale.

Honestly, at this point, I fail to see how anyone could interpret Upheaval Dome as an impact feature.

Shoemaker vs Jackson

Most readers of WUWT are familiar with the late Gene Schoemaker.

Gene Shoemaker – Founder of Astrogeology

April 28, 1928 – July 18, 1997

He once said he considered himself a scientific historian, one whose mission in life is to relate geologic and planetary events in a perspective manner. A modest statement coming from a legend of a man who almost single-handedly created planetary science as a discipline distinct from astronomy. He brought together geologic principles to the mapping of planets, resulting in more than 3 decades of discoveries about the planets and asteroids of the Solar System. He was a 1992 recipient of the National Medal of Science, the highest scientific honor bestowed by the President of the United States, then George Bush. His family, friends, former students, and the scientific community are in shock as they hear the news and feel the loss of “SuperGene.”

Dr. Gene Shoemaker died Friday, July 18, 1997 (Australian Time) in Alice Springs, Australia in a car accident. He was in the field, pursuing his lifelong passion of geologic studies to help understand impact craters with his wife and science partner, Carolyn Shoemaker. Carolyn survived the accident sustaining various injuries.

A longtime resident of Flagstaff, Arizona, in 1961 Gene invented the Branch of Astrogeology within the U.S. Geological Survey and established the Field Center in Flagstaff in 1963. Retired from the USGS in 1993, he has held an Emeritus position there and has been recently affiliated with Lowell Observatory in Flagstaff. An incredibly diverse person, he influenced science in numerous ways: most recently, in a decade-long sky survey for earth-crossing asteroids and comets, culminating in the discovery (with wife Carolyn and David Levy) of Comet Shoemaker-Levy, which impacted Jupiter in 1994, giving the world of science a major new insight into both the dynamics of comets and the planetary science of Jupiter. He has spent numerous summers (Australian winters) exploring ancient parts of the earth for records of meteorite and comet impacts, resulting in the discovery of a number of new craters. In much of his asteroid and comet work, Shoemaker collaborated closely with his wife, Carolyn, a planetary astronomer. A close and devoted couple, their work was recently featured in a 1997 National Geographic documentary “Asteroids: Deadly Impact.” They considered their work a “Mom and Pop” operation and together they initiated the Palomar Planet-crossing Asteroid Survey in 1973, and the Palomar Asteroid and Comet Survey in 1983.

Gene Shoemaker seems to have been a geologist from the day he was born in Los Angeles, California, in 1928. He did not even need to complete his higher education (B.S. and M.S., California Institute of Technology, 1947 and 1948; Ph.D. Princeton University after an interrupted career, 1960) before starting the practice of astrogeology that was to lead him to the planets. He began exploring for uranium deposits in Colorado and Utah in 1948, and these studies brought him geographically and intellectually near the many volcanic features and the one impact structure on the Colorado Plateau in the western United States, namely Hopi Buttes and Meteor Crater. In the period 1957-1960, he did his classic research on the structure and mechanics of meteorite impact. This work–including the discovery of coesite (a high pressure form of silica created during impacts) with E.C.T. Chao–provided the definitive work on basic impact cratering. It was work that he continued throughout his life–both by exploration of the earth–particularly in Australia–and the planets by remote sensing and mapping.

A man of vision, he believed geologic studies would be extended into space and in his early career he dreamed of being the first geologist to map the Moon. During the 1960’s he lead teams who were investigating the structure and history of the Moon and developing methods of planetary geologic mapping from telescope images of the Moon. A health problem prevented his being the first astronaut geologist, but he personally helped train the Apollo Astronauts and sat beside Walter Cronkite in the evening news giving geologic commentary during the Moon walks. He was involved in the Lunar Ranger and Surveyor programs, continued with the manned Apollo programs, and culminated his moon studies in 1994 with new data on the Moon from Project Clementine, for which he was the science-team leader.

Gene was the recipient of numerous awards including: Doctorate of Science Arizona State College, Flagstaff, 1965. Wetherill Medal of the Franklin Institute, co-recipient with E.C.T. Chao, 1965. Arthur S. Flemming Award, 1966. Doctorate of Science, Temple University, 1967. NASA Medal for Scientific Achievement, 1967. U.S. Department of the Interior Honor Award for Meritorious Service, 1973. Member, U.S. National Academy of Sciences, 1980. U.S. Department of the Interior Distinguished Service Award, 1980. Arthur L. Day Medal of the Geological Society of America, 1982. G.K. Gilbert Award of the Geological Society of America, 1983. Reiser Kulturpreis, co-recipient with E.C.T. Chao and Richard Dehm, 1983. Honorary Doctorate of Science, University of Arizona, 1984. Barringer Award of the Meteoritical Society, 1984. Kuiper Prize of the American Astronomical Society, Division for Planetary Sciences, 1984. Leonard Medal of the Meteoritical Society, 1985. Distinguished Alumni Award of the California Institute of Technology, 1986. Rittenhouse Medal of the Rittenhouse Astronomical Society, co-recipient with C.S. Shoemaker, 1988. U.S. National Medal of Science, 1992. Whipple Award, American Geophysical Union, 1993. Fellow, American Academy of Arts and Sciences, 1993. AIAA Space Science Award, 1996. NASA Exceptional Scientific Achievement Medal, 1996. Bowie Medal, American Geophysical Union, 1996. Special Award, American Association of Petroleum Geologists, 1997. Shoemaker Award, Texas Section of the American Institute of Professional Geologists, awarded posthumously, 1997.

From 1962 to 1985, Shoemaker blended his astrogeology research for the USGS with teaching at the California Institute of Technology (Caltech). He chaired Caltech’s Division of Geological and Planetary Sciences from 1969 to 1972. One of his doctorate students at Caltech, Dr. Susan Werner Kieffer, remembers him as being one of the most unfailingly generous, and intellectually honest mentors she has ever known. His colleagues at the USGS remember a exceptionally brilliant, exuberant, vibrant man and a warm human being whose angry antics over copy machines and loud happy laughter rang down the hallways. I remember a meeting when a newcomer to science overheard Gene’s excited conversation and laughter at a meeting and remarked “who is that loud guy?”–to which I replied that is the “god of planetary geology” and we all know that gods don’t whisper. As with his persona, Gene Shoemaker’s legacy will never be a whisper, but a loud burst onto the realm of Science that will be sorely missed. He is survived by his wife; his son, Patrick Shoemaker and wife Paula Kempchinsky; his daughters Christine Woodard and Linda Salazar and her husband Fred; and grandchildren, Sean and Adrian Woodard and Stefani Salazar, and a sister, Maxine Heath.

By Mary G. Chapman

USGS

On the other hand, I would guess that few WUWT readers and very few people outside the oil & gas industry are familiar with the work of the late Martin Jackson.

In Memoriam: Martin P. A. Jackson

June 1, 2016

Martin Jackson, world-renowned geoscientist and esteemed Bureau researcher, passed away early Tuesday, May 31.

Martin is recognized globally for his groundbreaking work in the field of salt tectonics, with over 100 papers and 3 books on the subject. Said Bureau colleague Michael Hudec in 2013: “He’s the number one person in the world by a goodly margin. His papers are universally regarded as the most authoritative on salt tectonics. And his name is associated with most of the major concepts in salt tectonics….You cannot work effectively in salt tectonics without reading Martin’s work.” In recent years, Jackson had been exploring signs of salt-tectonic activity on other planetary bodies, including Mars and Neptune’s moon Triton.

Born in Rhodesia (today, Zimbabwe), Jackson initially studied old, hard Precambrian gneisses before moving to Texas and eventually becoming immersed in, as he called it, “a subsurface world of very young, soft rocks.” He came to the Bureau in 1980 and in 1988 was instrumental in the creation of the Bureau’s first Industrial Associates program, the Applied Geodynamics Laboratory (AGL), founded to investigate the then-poorly-understood world of salt tectonics. With seed money from UT Austin and the member support of 13 oil and gas companies, Jackson’s new consortium became a model for those to follow. Over 25 years after its founding, the AGL now maintains over 30 participating companies and is widely considered the world’s preeminent salt-tectonics research laboratory. Today, it is almost impossible to talk about salt tectonics without using terms and concepts developed at the AGL, including salt canopy, salt weld, reactive diapir, squeezed diapir, extrusive salt sheet, and multidirectional extension.

Jackson’s numerous major career honors include the American Association of Petroleum Geologists’ Robert R. Berg Outstanding Research Award (2010) in recognition of outstanding innovation in petroleum geoscience research and the Geological Society of London’s William Smith Medal (2013) for outstanding research in applied geology. According to AAPG records, no one has won more AAPG technical awards, nor has anyone won in as many technical categories. Jackson’s notable publications include the AAPG Memoir Salt Tectonics: A Global Perspective (2008, with David Roberts and Sig Snelson), a definitive book on the subject, and the major 2012 atlas The Salt Mine (with Bureau colleague Hudec), an interactive resource on salt tectonics. Jackson’s publication legacy will continue as co-author (also with Hudec) of the forthcoming Salt Tectonics: Principles and Practice, to be published in September 2016 by Cambridge University Press.

In addition to his preeminence as a research scientist, Martin Jackson is equally regarded for his strength of character, gracious demeanor, and unfailing humor. His friends and peers recall his kindness, humility, insightfulness, and remarkable equanimity.

Bureau director Scott W. Tinker said, in conveying the loss of his friend to the Bureau family, that “Martin was one of the finest people I have known. Practical. Brilliant. Creative. Dedicated to his family and his science until the end. He will be missed but always remembered.”

Bureau of Economic Geology, The University of Texas at Austin

Gene Shoemaker and Martin Jackson were brilliant geologists and the leading scientists, if not founders, of their respective disciplines.  Both have written extensively on the subject of Upheaval Dome, they have built upon each other’s work and that of other geoscientists… And they couldn’t have disagreed any more profoundly.  Both of these brilliant geologists, employing the archaic principles of uniformitarianism, came to very firm and diametrically opposing conclusions.  Maybe… If they had just drawn cartoons on Google Earth images… Sorry, couldn’t resist…

Here is a sampling of the back-and-forth:

Jackson 1998…

Structure and evolution of Upheaval Dome: A pinched-off salt diapir

Abstract

Upheaval Dome (Canyonlands National Park, Utah) is an enigmatic structure previously attributed to underlying salt doming, cryptovolcanic explosion, fluid escape, or meteoritic impact. We propose that an overhanging diapir of partly extrusive salt was pinched off from its stem and subsequently eroded. Many features support this inference, especially synsedimentary structures that indicate Jurassic growth of the dome over at least 20 m.y. Conversely, evidence favoring other hypotheses seems sparse and equivocal.

In the rim syncline, strata were thinned by circumferentially striking, low-angle extensional faults verging both inward (toward the center of the dome) and outward. Near the dome’s core, radial shortening produced constrictional bulk strain, forming an inward-verging thrust duplex and tight to isoclinal, circumferentially trending folds. Farther inward, circumferential shortening predominated: Radially trending growth folds and imbricate thrusts pass inward into steep clastic dikes in the dome’s core.

We infer that abortive salt glaciers spread from a passive salt stock during Late Triassic and Early Jurassic time. During Middle Jurassic time, the allochthonous salt spread into a pancake-shaped glacier inferred to be 3 km in diameter. Diapiric pinch-off may have involved inward gravitational collapse of the country rocks, which intensely constricted the center of the dome. Sediments in the axial shear zone beneath the glacier steepened to near vertical. The central uplift is inferred to be the toe of the convergent gravity spreading system.

Jackson et al., 1998

Shoemaker 1999…

Geology of the Upheaval Dome impact structure, southeast Utah

Abstract. Two vastly different phenomena, impact and salt diapirism, have been proposed for the origin of Upheaval Dome, a spectacular scenic feature in southeast Utah. Detailed geologic mapping and seismic refraction data indicate that the dome originated by collapse of a transient cavity formed by impact. Evidence is as follows: ( 1) sedimentary strata in the center of the structure are pervasively imbricated by top-toward-the-center thrust faulting and are complexly folded as well; (2) top-toward-the-center normal faults are found at the perimeter of the structure; (3 ) clastic dikesa re widespread; (4 ) the top of the underlying salt horizon is at least 500 m below the surface at the center of the dome, and there are no exposures of salt or associated rocks of the Paradox Formation in the dome to support the possibility that a salt diapir has ascended through it; and (5) planar microstructures in quartz grains, fantailed fracture surfaces (shatter surfaces), an rare shatter cones are present near the center of the structure. We show that the dome formed mainly by centerward motion of rock units along listric faults. Outcrop-scale folding and upturning of beds, especially common in the center, are largely a consequence of this motion. We have also detected some centerward motion of  fault-bounded wedges resulting from displacements on subhorizontal faults that conjoin and die out within horizontal bedding near the perimeter of the structure.  The observed deformation corresponds to the central uplift and the encircling ring structural depression seen in complex impact craters.

[…]

The presence of known salt structures in the region influenced early interpretations that Upheaval Dome resulted from salt diapirism, but it is noteworthy that there are no other similar-size domal structures visible elsewhere in this part of the Colorado Plateau.

[…]

Kriens, Shoemaker and Herkenoff, 1999

Nothing described in Kriens et al., 1999 is inconsistent with a pinched-off salt diapir.  I’ve worked salt basins since 1981 (East Texas and the Gulf of Mexico) and I’ve seen plenty of salt structures that didn’t look like any other salt structures in their respective basins.

Naturally, being an oil industry geoscientist, who has spent his entire career working salt basins and learned most of what I know about salt tectonics from the works of Martin Jackson and interpreting seismic data in East Texas and the Gulf of Mexico, I am clearly biased in favor of Martin Jackson’s interpretation.  Petroleum geologists have been predisposed to various salt diapir hypotheses for a very long time.

I am fortunate enough to have an original 1972 copy of this book (along with a mimiograph copy of the errata).

×20180525_050204

Figure 17.  ‘RMAG’s Geologic Atlas of the Rocky Mountain Region was an instant classic when published in 1972 on the occasion of RMAG’s 50th Anniversary. Affectionately known as the “Big Red Book,” its extensive paleogeographic maps remain a valuable resource to this day. The Atlas was the product of six years labor with an editorial staff of 26 and authors hailing from 43 separate companies and institutions.” http://store.aapg.org/detail.aspx?id=1169

20180525_045658

Figure 18.  “The structure is a collapsed salt dome in the Paradox basin.”

Uhm… yeah.

Upheaval Dome *should* appear different than any other salt structure in the Paradox Basin:

Paradox_Top_of_Salt

Figure 19.  Structure map of top of Paradox Salt Formation. Contour interval = 1,000′. Utah Geological Survey.

The most prominent salt structures in the Paradox Basin are the elongate “salt walls” in the northeastern part of the basin.  These NW-SE striking features are up to 100 miles long, with 6,000′ of vertical relief.  The salt is subaerially exposed in several locations along the crests of the salt walls.

Upheaval Dome is in the southwestern part of the basin.  It is in an area where the salt structures are primarily low-relief salt-cored anticlines (bumps), many of which are elongated.  Upheaval Dome has much higher vertical relief (>2,000′) than any nearby salt anticline and is nearly circular.

It’s obvious from this gravity map that Upheaval Dome is unlike any other salt structure in the Paradox Basin:

Paradox_Gravity_Map

Figure 20.  Paradox Basin gavity gradient map. Geesaman 2015. Upheaval Dome sticks out like a sore thumb.  The salt walls are the elongate red anomalies that parallel Salt, Cache, Fisher, Sinbad, Paradox, Gypsum and Moab Valleys.

In 2000 NASA sponsored a seismic reflection and refraction survey in an effort to image the subsurface structure (Kanbur et al., 2000).  They concluded that there was no evidence of a salt diapir beneath Upheaval Dome, despite the fact that their seismic profiles didn’t cover the dome itself.  They only covered the rim monocline and rim syncline.  The seismic profiles were consistent with both hypotheses.  However, it did indicate the presence of salt beneath the rim syncline; which is unusual, but not unprecedented, for a pinched-off salt diapir.

In 2001, Martin Jackson published a book on Upheaval Dome that addressed the conclusions of Krien’s et al., 1999 (Shoemaker), particularly the crushed quartz grains and clastic dikes:

Structure and Evolution of Upheaval Dome: Pinched-Off Salt Diapir or Meteoritic Impact Structure?

Abstract

Upheaval Dome (Canyonlands National Park, Utah) is an enigmatic structure previously attributed to underlying salt doming, cryptovolcanic explosion, fluid escape, or meteoritic impact. We instead propose that an overhanging diapir of partly extrusive salt was pinched off from its stem and subsequently eroded. Many features support this inference, especially synsedimentary structures that indicate Jurassic growth of the dome over at least 20 m.y. Conversely, evidence favoring other hypotheses is sparse and equivocal.

[…]

Crushed Quartz Grains

Quartz grains that have been crushed or shattered into pieces in the clastic dikes were used as evidence of impact by Shoemaker and Herkenhoff (1984), and although we found microfractured quartz in the dikes (fig. 40), even widespread microfractured quartz is geologically common. For example, quartz grains are crushed and mechanically rearranged by compaction during burial (Milliken, 1994; Dickinson and Milliken, 1995); they are common in fault zones within 100 m of even small-displacement (~100 m) fault surfaces (Anders and Wiltschko, 1994).  Microfractures are typically masked by recementation of authigenic quartz between and in optical continuity with the shards. Electron-beam-induced cathodoluminescence of our Upheaval Dome sample reveals that the quartz undulatory extinction is caused by slightly misoriented grain fragments separated by microfractures sealed by cement (fig. 40a). Brittle deformation and sealing of this type is common in faulted rocks (Anders and Wiltschko, 1994).

Jackson et al., 2001 pg 55

The downloadable PDF is available from the Texas Bureau of Economic Geology for $15.

Jackson compiled a table of the evidence for and against both an impact feature and a pinched-off salt diapir.

Table 1 from Jackson et al., 2001…

Incompat. with impact Compat. with pinch-off Compat. with impact Incompat. with pinch-off
POSITIVE EVIDENCE
Circularity X X
Central uplift X X
Clastic dikes X X
Crushed quartz grains X X
Inner constrictional zone X X
Outer extensional zone X X
Radial flaps (dog tongues) X X
Presence of underlying salt X X
Gravity and magnetic anomalies X X
Contiguous anticline X X
Nearby salt structures X X
Rim syncline X X
Rim monocline X X
Growth folds X X
Growth faults X X
Shifting rim synclines X X
Truncations and channeling X X
Onlap X X
Multiple fracturing and cementation X X
Steep zones X X
Outward-verging  extension X X
Volume imbalance X X
Shatter cones X X
Salt below rim syncline X X
NEGATIVE EVIDENCE
Absence of salt at the surface X X
Paucity of nearby piercement diapirs X X
Absence of meteoritic material X X
Absence of melt X X
Absence of in-situ breccia X X
Absence of shock-metamorphic minerals X X
Paucity of planar microstructures in quartz X X
Absence of ejecta breccia X X
Absence of outer fault terracing X X
Absence of overturned peripheral flap X X

The evidence overwhelmingly supported the salt diapir hypothesis.  Although it clearly did not rule out an impact feature, as most of the positive evidence was consistent with both hypotheses.

At this point, the score was:

  • Pinched off salt diapir 30
  • Impact crater -2

Then along came a “smoking gun”

Upheaval Dome, Utah, USA: Impact origin confirmed

Abstract

Upheaval Dome is a unique circular structure on the Colorado Plateau in SE Utah, the origin of which has been controversially discussed for decades. It has been interpreted as a crypto volcanic feature, a salt diapir, a pinched-off salt diapir, and an eroded impact crater.  While recent structural mapping, modeling, and analyses of deformation mechanisms strongly support an impact origin, ultimate proof, namely the documentation of unambiguous shock features, has yet to be successfully provided. In this study, we document, for the first time, shocked quartz grains from this crater in sandstones of the Jurassic Kayenta Formation. The investigated grains contain multiple sets of decorated planar deformation features. Transmission electron microscopy (TEM) reveals that the amorphous lamellae are annealed and exhibit dense tangles of dislocations as well as trails of fluid inclusions. The shocked quartz grains were found in the periphery of the central uplift in the northeastern sector of the crater, which most likely represents the cross range crater sector.

Buchner & Kenkmann, 2008

This bit is laughable:

While recent structural mapping, modeling, and analyses of deformation mechanisms strongly support an impact origin…

Prior to the discovery of 2 shocked quartz grains in the Early Jurassic Kayenta Formation, there was no unambiguous evidence that Upheaval Dome was an impact feature.  However, the detection of planar deformation features (PDF’s) did provide clear evidence for a meteoric impact.

Final Score

  • Pinched off salt diapir 28
  • Impact crater 0

Unless… the PDF’s were examples of tectonic deformation lamellae in quartz.  Or the 2 shocked quartz grains were detrital… as are most quartz grains in sandstone.

However, the PDF’s do appear to be evidence of an impact event at Upheaval Dome… or somewhere else in or around the Paradox Basin at some point in time before, during or after the deposition of the Kayenta Formation.  Think about how quartz grains get into sandstone.

End-o-story… Right?  Wrong.

Nothing is over until we say it’s over!

New Evidence for Long-Term, Salt Related Deformation at Upheaval Dome, SE Utah*

Patrick J. Geesaman 1, Bruce D. Trudgill 2, Thomas E. Hearon IV 3, and Mark G. Rowan 4

Search and Discovery Article #10756 (2015)**  Posted August 3, 2015  *Adapted from oral presentation given at AAPG Annual Convention & Exhibition, Denver, Colorado, May 31-June 3, 2015

**Datapages © 2015 Serial rights given by author. For all other rights contact author directly.

1 Anadarko Petroleum Corporation, Houston, TX, USA

2 Geology & GE, Colorado School of Mines, Golden, CO, USA (btrudgil@mines.edu)

3 Structure and Geomechanics, Geological Technology, ConocoPhillips Company, Houston, TX, USA

4 Rowan Consulting, Inc., Boulder, CO, USA

Abstract

Upheaval Dome is an eroded structural dome that exposes Mesozoic strata along with associated folds, faults and sand injectites in the Paradox basin, SE Utah. Multiple interpretations for its origin have been proposed, but the two remaining viable hypotheses are at opposite ends of the geologic spectrum: one proposing long-term salt-related deformation and growth of the structure, the other a catastrophic meteorite impact.  Analysis of stratigraphic field data collected in Triassic to Jurassic-aged strata adjacent to Upheaval Dome reveals: (1) stratigraphic thicknesses from measured sections for the Kayenta Formation (~199 to ~195 Ma) that range from 7 meters to 224 meters, and projected thicknesses in cross section that can exceed 400 meters; (2) distinct changes in facies distributions in relation to mapped structures; (3) localized angular unconformities and stratal-onlap surfaces; (4) blocks of Triassic Chinle Formation encased in younger Jurassic Wingate Sandstone adjacent to thinned, Wingate lobes, that apparently downlap onto the underlying Chinle. Structural analysis at Upheaval Dome reveals: (1) synclinal growth axes and associated depositional centers shift away from the center of the dome throughout the Late Triassic/Early Jurassic; (2) stratigraphic thicknesses increase across normal faults on the scale of meters to tens of meters; (3) thrust faults within the Kayenta Formation verge to the southeast regardless of location around the structure. These structural features and associated growth strata offer compelling evidence for long-term deformation compatible with salt tectonics at Upheaval Dome during the Late Triassic/Early Jurassic. Sparse indicators of catastrophic impact are present in the Kayenta Formation in the form of two shocked quartz grains, orders of magnitude less than would be expected <1 km from a meteorite impact site. We interpret these grains to be detrital and sourced from outside the Paradox basin. In our interpretation of salt-related deformation, we discuss the merits and drawbacks of a model invoking collapse over a buried salt high to a prior model of a pinched-off diapiric feeder to an eroded salt glacier. The possibility that a meteorite impact of Late Permian to Early Triassic age initiated the growth of an isolated salt pillow in the western part of the northern Paradox Basin requires further investigation.

AAPG Search and Discovery

Instead of a post-Jurassic impact event (< 2 minutes) vs. slow, steady growth of a subsequently pinched-off salt diapir from the Late Triassic through at least the Early Jurassic (>20 million years)… Geesamen et al., 2015 put forward the hypothesis that an impact occurred much earlier, during the Early Triassic followed by the initiation of salt movement and the slow growth of a salt dome from the Early Triassic (~250-240 Ma) through at least the Early Jurassic (~195-170 Ma), a period of 45 to 80 million years.  This actually better explains the presence of at least 2 shocked quartz grains in the Early Jurassic Kayenta Formation than a post-Jurassic impact does.  It also explains the clear stratigraphic evidence for slow structural growth over millions of years.

There you have it, a hypothesis that accommodates all of the unambiguous evidence.

  • Unambiguous evidence for an impact: 2 shocked quartz grains in the Early Jurassic.
  • Unambiguous evidence for a salt diapir: Structural growth from the Late Triassic through Early Jurassic.

We have both kinds…

We have both kinds of evidence: Salt diapirism and meteoric impact.

QED

Figure 21. Evidence of syndepostional structural growth around Upheaval Dome is unambiguous evidence that the structure was formed over a period of at least 45-70 million years. Geesamen et al., 2015.

I’m sure someone is asking, “How could it be possible that two of the foremost geologists in the world could look at the same data and come away with diametrically opposing interpretations?  Furthermore, how could a geologist barely out of grad school come along and demonstrate that they were both wrong?”  

Even if no one is asking this question, or questions, I’ll answer it with a poem (and I hate poetry almost as much as I hate folk music):

Bally_Seis_Strat

Figure 22.  Geology & geophysics are often analogous to a group of blind men interpreting an elephant.  AAPG.

Since the image is probably too small to read, here’s the poem…

It was six men of Indostan,

To learning much inclined,

Who went to see the Elephant

(Though all of them were blind),

That each by observation

Might satisfy his mind.

The First approach’d the Elephant,

And happening to fall

Against his broad and sturdy side,

At once began to bawl:

“God bless me! but the Elephant

Is very like a wall!”

The Second, feeling of the tusk,

Cried, -“Ho! what have we here

So very round and smooth and sharp?

To me ’tis mighty clear,

This wonder of an Elephant

Is very like a spear!”

The Third approach’d the animal,

And happening to take

The squirming trunk within his hands,

Thus boldly up and spake:

“I see,” -quoth he- “the Elephant

Is very like a snake!”

The Fourth reached out an eager hand,

And felt about the knee:

“What most this wondrous beast is like

Is mighty plain,” -quoth he,-

“‘Tis clear enough the Elephant

Is very like a tree!”

The Fifth, who chanced to touch the ear,

Said- “E’en the blindest man

Can tell what this resembles most;

Deny the fact who can,

This marvel of an Elephant

Is very like a fan!”

The Sixth no sooner had begun

About the beast to grope,

Then, seizing on the swinging tail

That fell within his scope,

“I see,” -quoth he,- “the Elephant

Is very like a rope!”

And so these men of Indostan

Disputed loud and long,

Each in his own opinion

Exceeding stiff and strong,

Though each was partly in the right,

And all were in the wrong!

MORAL,

So, oft in theologic wars

The disputants, I ween,

Rail on in utter ignorance

Of what each other mean;

And prate about an Elephant

Not one of them has seen!

Blind Men and the Elephant – A Poem by John Godfrey Saxe via All About Philosophy

That said… It’s a salt diapir… Sorry.

FYI

I have tried to limit the direct quoting of papers and books to the abstracts and limit the direct use of images from those papers to the bare minimum I felt was needed to tell this story. If your’e interested in a “deeper dive”… The full text of most of the papers is available and can be accessed through links in the post and in the references section.  The most notable exception is Martin Jackson’s book on Upheaval Dome.  Papers for which I have PDF’s (not planar deformation features) and felt it was OK to share them are also linked in the references section.

Yes… I did aspire to be John Belushi from 1976-1980.

 

Applications to climate science

“The Blind Men and the Elephant” is even more applicable to climate science than it is to geology & geophysics.  The difference is that most climate scientists don’t seem to realize this.

Did you ever notice how government and closely affiliated academic scientists seem to interpret data with the intent of finding a specific answer, while private sector and closely affiliated academic scientists interpret data with the intent of finding the answer that best explains all of the observations?  I notice this all the time.  In the case of Upheaval Dome, it seems that NASA-affiliated scientists were hell-bent on it being an impact feature.  So hell-bent as to basically ignore almost all of the evidence.  This strikes me as being very similar to the way government and closely affiliated academic climate scientists tend to view things…

slide12

JC at the National Press Club, Climate Etc.

Glossary

Anticline

1. n. [Geology]

An arch-shaped fold in rock in which rock layers are upwardly convex. The oldest rock layers form the core of the fold, and outward from the core progressively younger rocks occur. Anticlines form many excellent hydrocarbon traps, particularly in folds with reservoir-quality rocks in their core and impermeable seals in the outer layers of the fold. A syncline is the opposite type of fold, having downwardly convex layers with young rocks in the core.

Breccia

Breccia is a term most often used for clastic sedimentary rocks that are composed of large angular fragments (over two millimeters in diameter). The spaces between the large angular fragments are filled with a matrix of smaller particles and a mineral cement that binds the rock together.

Clastic

1. n. [Geology]

Sediment consisting of broken fragments derived from preexisting rocks and transported elsewhere and redeposited before forming another rock. Examples of common clastic sedimentary rocks include siliciclastic rocks such as conglomerate, sandstone, siltstone and shale. Carbonate rocks can also be broken and reworked to form clastic sedimentary rocks.

Clastic dike

A tabular body of clastic material transecting the bedding of a sedimentary formation, representing extraneous material that has invaded the containing formation along a crack, either from below or from above.

Detrital

1. adj. [Geology]

Pertaining to particles of rock derived from the mechanical breakdown of preexisting rocks by weathering and erosion. Detrital fragments can be transported to recombine and, through the process of lithification, become sedimentary rocks. Detrital is usually used synonymously with clastic, although a few authors differentiate between weathering of particles, which forms detrital sediments, and mechanical breakage, which produces clastic sediments.

Diapir

1. n. [Geology]

A relatively mobile mass that intrudes into preexisting rocks. Diapirs commonly intrude vertically through more dense rocks because of buoyancy forces associated with relatively low-density rock types, such as salt, shale and hot magma, which form diapirs. The process is known as diapirism. By pushing upward and piercing overlying rock layers, diapirs can form anticlines, salt domes and other structures capable of trapping hydrocarbons. Igneous intrusions are typically too hot to allow the preservation of preexisting hydrocarbons.

OGL98055-t

Listric fault

1. n. [Geology]

A normal fault that flattens with depth and typically found in extensional regimes. This flattening manifests itself as a curving, concave-up fault plane whose dip decreases with depth.

Monocline

(geology) A unidirectional dip in strata that is not a part of an anticline or syncline

(geology) A single flexure in otherwise flat-lying strata

Planar deformation features

Planar deformation features, or PDFs, are optically recognizable microscopic features in grains of silicate minerals (usually quartz or feldspar), consisting of very narrow planes of glassy material arranged in parallel sets that have distinct orientations with respect to the grain’s crystal structure.

PDFs are only* produced by extreme shock compressions on the scale of meteor impacts. They are not found in volcanic environments. Their presence therefore is a primary criterion for recognizing that an impact event has occurred.

* Except when PDF’s are produced by tectonic forces.

Rim syncline

A syncline partially surrounding a salt dome. It results from withdrawal of salt that has moved into the dome.

Syncline

1. n. [Geology]

Basin- or trough-shaped fold in rock in which rock layers are downwardly convex. The youngest rock layers form the core of the fold and outward from the core progressively older rocks occur. Synclines typically do not trap hydrocarbons because fluids tend to leak up the limbs of the fold. An anticline is the opposite type of fold, having upwardly-convex layers with old rocks in the core.

Syndepositional

(geology) Occurring at the same time as deposition

References

Billingsly, George H. and William J. Breed.  “Capitol Reef Geological Cross Section.” Published by the Capitol Reef Natural History Association, Torrey Utah 84775 ©1980 Capitol Reef Natural History Association. Reprinted 1996 Lithography by Lorraine Press Salt Lake City, Utah

Blenkinsop T. G. and Drury M. R. D. 1988. Stress estimates and fault history from quartz microstructures. Journal of Structural Geology 10:673–684.

Brunetti, Maria. (2014). “Statistics of terrestrial and extraterrestrial landslides.” PhD Thesis. 10.13140/2.1.4107.3444.

Buchner, Elmar & Kenkmann, Thomas. (2008). “Upheaval Dome, Utah, USA: Impact origin confirmed.” Geology. 36. 227-230. 10.1130/G24287A.1.

Cramez, Carlos. “Glossary of Salt Tectonics.” (2006).  Universidade Fernando Pessoa. Porto, Portugal.

Geesaman, J., Patrick & Trudgill, Bruce & Hearon, Thomas & Rowan, Mark. (2015). “New Evidence for Long-Term, Salt-Related Deformation at Upheaval Dome, SE Utah.”  2015 AAPG Annual Convention and Exhibition, At Denver Colorado.

Hamers, Maartje & Drury, M.R.. (2011). “Scanning electron microscope‐cathodoluminescence (SEM‐CL) imaging of planar deformation features and tectonic deformation lamellae in quartz.” Meteoritics & Planetary Science. 46. 1814 – 1831. 10.1111/j.1945-5100.2011.01295.x.

Jackson, Martin & Schultz-Ela, Dan & Hudec, Michael & Watson, IA & L. Porter, M. (1998). “Structure and evolution of Upheaval Dome: A pinched-off salt diapir.” Geological Society of America Bulletin – GEOL SOC AMER BULL. 110. 1547-1573. 10.1130/0016-7606(1998)110<1547:SAEOUD>2.3.CO;2.

Jackson, M.P.A., D. D. Schultz-Ela, M. R. Hudec, I. A. Watson, and M. L. Porter.  RI0262. “Structure and Evolution of Upheaval Dome: Pinched-Off Salt Diapir or Meteoritic Impact Structure?”  Bureau of Economic Geology, The University of Texas at Austin. 2001.

Kanbur, Z., J. N. Louie, S. Chávez‐Pérez, G. Plank, and D. Morey (2000), Seismic reflection study of Upheaval Dome, Canyonlands National Park, Utah. J. Geophys. Res.105(E4), 9489–9505, doi:10.1029/1999JE001131.

Kriens, Bryan & M. Shoemaker, Eugene & Herkenhoff, K. (1999). “Geology of the Upheaval Dome impact structure, southeast Utah.” Journal of Geophysical Research. 104. 18867-18888. 10.1029/1998JE000587.

Kring, David A.  “Guidebook to the Geology of Barringer Meteorite Crater Arizona (a.k.a. Meteor Crater).” 2nd edition ©2017, Lunar and Planetary Institute LPI Contribution No. 2040

Naqi Mohammad, Bruce Trudgill and Charles Kluth.  “A New Insight on the Mechanism of Salt Wall Collapse in Northeastern Paradox Basin, Utah.”  Search and Discovery Article #10837 (2016).  Adapted from poster presentation given at AAPG Annual Convention & Exhibition, Denver, Colorado, May 31-June 3, 2015.

Roddy, D. J., Boyce, J. M., Colton, G. W., & Dial, A. L., Jr.  “Meteor Crater, Arizona, rim drilling with thickness, structural uplift, diameter, depth, volume, and mass-balance calculations.” Lunar Science Conference, 6th, Houston, Tex., March 17-21, 1975, Proceedings. Volume 3. (A78-46741 21-91) New York, Pergamon Press, Inc., 1975, p. 2621-2644. Research supported by the U.S. Defense Nuclear Agency.

Trudgill, Bruce. (2010). “Evolution of salt structures in the northern Paradox Basin: Controls on evaporite deposition, salt wall growth and supra-salt stratigraphic architecture: Evolution of salt structures in the northern Paradox Basin.” Basin Research. 23. 208 – 238. 10.1111/j.1365-2117.2010.00478.x.

USGS Astrogeology Science Center.  Meteor Crater Sample Collection / Interactive Map.

Utah Geological Survey. GEOSIGHTS: UTAH’S BELLY BUTTON, UPHEAVAL DOME

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Tom Halla

Good article. Definite proof you know geology well enough to explain the details to people like me who never took a geology course.

Felix
Felix
Felix

Salt of the Earth.

The middle of North America was repeatedly inundated by epicontinental seas during the Jurassic and Cretaceous. The Jurassic Sundance Sea (five marine transgressions from the Arctic Ocean) is less well known than the Western Interior Seaway running from the Gulf of Mexico to the Arctic Ocean in the Cretaceous.

https://en.wikipedia.org/wiki/Sundance_Sea

Felix

This famous mid-Jurassic deposit, for instance, familiar to oilmen, er, persons of petroleum:

https://en.wikipedia.org/wiki/Louann_Salt

Felix

Derrick trash?

Felix

Except for the Middle Jurassic, western North America is blessed with abundant avian and non-avian dinosaur fossils from every epoch of their existence, unless you consider that they evolved in the Middle Triassic rather than Late.

The dinosaur fauna of the Late Jurassic is probably the most famous, featuring giant sauropods, armored stegosaurs and ankylosaurs and carnivorous theropods such as Allosaurus from the Morrison Formation (156-147 Ma) of the Colorado Plateau. But the Late Cretaceous (67-66 Ma) Hell Creek Formation from the other side of the Rockies is right up there in notoriety, with birds, dinobirds, T. rex, Triceratops, duck-billed hadrosaurs and advanced ankylosaurs.

The first non-avian dinosaur ever described, by the Victorian eccentric Rev. Buckland, was the English Middle Jurassic Megalosaurus, a basal tetanuran theropod.

Felix

Offtopic, but the official geologic periods and epochs annoy me. The Cretaceous Period lasted longer than the Triassic or Jurassic, yet it has only two epochs instead of three.

Worse, both epochs of the Cretaceous are longer than the entire Silurian Period, and the Early Cretaceous lasted longer than the Ordovician Period.

At least the Gelasian (~2.6 – 1.8 Ma), formerly the last age of the Pliocene Epoch, has been attached to the following Pleistocene, where it belongs, since the NH glaciations began during it.

The Oligocene Epoch (when Antarctica iced over) of our current Cenozoic Era similarly ought to join the present Neogene Period, during which Earth has cooled, rather than be attached to the toasty epochs of the Paleogene, but then the Pg would have only two short epochs, the Paleocene and Eocene.

Thanks for this large and most interesting effort. Permalinked, because it vividly illustrates the actual workings of ‘science’. Both founding experts, Shoemaker and Jackson, remind me of the old adage, ‘if all you have is a hammer, all fasteners look like nails’.

Felix

According to Wikipedia, Upheaval Dome is an “impact structure”:

https://en.wikipedia.org/wiki/Upheaval_Dome

David, you might want to edit that entry.

William Astley

Wikipedia articles are not always correct.

This is the paper which the Wikipedia article refers to. The paper authors assert the finding of shocked quartz is strong support for the impact origin of Upheaval Dome.

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/36/3/227/29673/upheaval-dome-utah-usa-impact-origin-confirmed?redirectedFrom=fulltext

Upheaval Dome, Utah, USA: Impact origin confirmed

Upheaval Dome is a unique circular structure on the Colorado Plateau in SE Utah, the origin of which has been controversially discussed for decades. It has been interpreted as a crypto volcanic feature, a salt diapir, a pinched-off salt diapir, and an eroded impact crater. While recent structural mapping, modeling, and analyses of deformation mechanisms strongly support an impact origin, ultimate proof, namely the documentation of unambiguous shock features, has yet to be successfully provided. In this study, we document, for the first time, shocked quartz grains from this crater in sandstones of the Jurassic Kayenta Formation. The investigated grains contain multiple sets of decorated planar deformation features. Transmission electron microscopy (TEM) reveals that the amorphous lamellae are annealed and exhibit dense tangles of dislocations as well as trails of fluid inclusions. The shocked quartz grains were found in the periphery of the central uplift in the northeastern sector of the crater, which most likely represents the cross range crater sector.

John Brisbin

The new text font makes the articles illegible in my browsers. Even magnified two steps, it is less readable than yesterday’s font.

C. Paul Barreira

Quite the opposite. Today’s font, as I read it now, may be one called PT Serif. Perhaps, perhaps not. But it is a vast improvement on the Helvetica Light of yesterday.

cbrianb

I have a question. Do diapirs ever contain schist? (I couldn’t contain myself)

Plus many. A dirty geology funny punny

Bob boder

HA!

Thomas C Bakewell

Somewhere in the early 80’s the company I was with leased a “funny looking thing” prospect somewhere around West Cameron 310. I did a bright spot analysis with really primitive AVO, It wasn’t a bright spot caused by gas. Drilling encountered a hard streak at about 6500 ft. Hmmm.

Somewhat later I wound up looking at salt domes in offshore Louisiana for Pennzoil Sulphur. With gravity and seismics one can roughly determine the presence, and possible thickness of caprock on a shallow dome.They leased West Cameron 306 and cored it three times. At about 2200 ft abundant caprock was found. Alas,no native sulphur was left. What was present was in the form of semi-massive chunks of iron pyrite in carbonate rock. Sure wish I had some caprock samples now for thin sections and SEM work.

Somewhat later I decided that the hard streak found in ?WC-310 was really the remnants of caprock left after a small salt dome had been completely dissolved.

I’ve been to Upheaval Dome. At the time, the evidence of planar deformation features pushed me into the impact structure camp. I did not consider that where something is found just might not be where it was created. Bad geologist, No martini!

I loved working with salt tectonics, did a lot in interior basin and GOM to late 80’s, then off to the Pre-Caspian Basin for a short stint.

Working with reasonable seismic and gravity data density and modeling followed by drilling. It was a dream life.

I’m off to the watering hole with a printed copy of your work. May take me two Narwals to get into it.

You are a supurb writer and I really enjoy whatever you have to share with us. Thank you

Tom Bakewell, semi-retired geo-head.

Javier

It is really funny that you would write this today:

It was six men of Indostan,
To learning much inclined,
Who went to see the Elephant
(Though all of them were blind)…

“The Blind Men and the Elephant” is even more applicable to climate science than it is to geology & geophysics. The difference is that most climate scientists don’t seem to realize this.

When just yesterday I drew exactly the same for Judith Curry’s blog:
comment image

Too bad WUWT is not displaying images yet.

For a total outsider, the images and geological descriptions make more sense for a pinched-off salt diapir than for an impact crater. But what would I know? As you say “I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail.” And some famous scientists are also famous for never conceding a point even when they are clearly wrong.

Each specialist, each dry-as-dust
And professorial oaf,
Holds up his little crumb of crust
And cries, “Behold the loaf!”

Felix

After the Alvarez hypothesis for the K-T mass extinction event was generally accepted, especially after the Yucatan impact site was identified, ET impacts became the new paradigm. People started looking for craters, shocked quartz, iridium layers and other signs of bolide collisions to explain the previous MEEs in the paleontological record, and even for lesser extinctions.

Shocked quartz is actually fairly common, such that even when found in deposits more or less of the right age, their discovery isn’t dispositive. That’s the case with the Triassic-Jurassic MEE, which more likely is associated with the CAMP and start of the breakup of Pangaea. No suitable crater has been found, although at ~201 Ma, any impact site would probably have been reworked if the bolide hit in an ocean basin.

Felix

Such is the power of a prevailing paradigm.

M Courtney

Being a reasonable man I am willing to accept the compromise.
Both are right.

This is an underlying salt dome (common in the area) that happened to be hit by a meteorite.

A theory that explains all the evidence. And isn’t that improbable.
Over the life of the Earth many things will happen once.

Felix

David cites a 2015 paper (Geesaman, et al) that suggests both an impact and a salt dome, but in the reverse order from your proposed compromise. DM wrote:

“Instead of a post-Jurassic impact event (20 million years)… Geesamen et al., 2015 put forward the hypothesis that an impact occurred much earlier, during the Early Triassic followed by the initiation of salt movement and the slow growth of a salt dome from the Early Triassic (~250-240 Ma) through at least the Early Jurassic (~195-170 Ma), a period of 45 to 80 million years. This actually better explains the presence of at least 2 shocked quartz grains in the Early Jurassic Kayenta Formation than a post-Jurassic impact does. It also explains the clear stratigraphic evidence for slow structural growth over millions of years.

“There you have it, a hypothesis that accommodates all of the unambiguous evidence.

“Unambiguous evidence for an impact: 2 shocked quartz grains in the Early Jurassic.
Unambiguous evidence for a salt diapir: Structural growth from the Late Triassic through Early Jurassic.”

David ==> #11 — You might be a geologist if you can write 7,000 words about a hole in the ground half-full of rocks — and call it the “the bare minimum I felt was needed to tell this story.”
Man, you must really love rocks!

Don K

Very nice article. I’m not much of a geologist, but when I go out to look at a rock formation armed with a geologic paper, what I find is frequently substantially different from what I expected to find. It’s really hard to describe rocks — especially in areas that have been subject to deformation — which seems to be most of the interesting ones. It doesn’t suprise me at all to find that two first class geologists can come up with substantially differing interpretations of a complex geologic feature.. Consider the controversies that first class paleontologists can conjure up from a few broken vertebrate teeth.or a handful of invertebrate scraps from the Lower Cambrian.

I’ll buy that the shocked quartz possibbly indicates a youngest date for an impact — assuming that they are related to whatever formed your crater … ehrr … “feature”. But how does one know they aren’t from, for example, a Cambrian or older impact transported via wind and water to the Mesozoic Colorado Plateau?

John Harmsworth

CAGW logic must surely apply to this contribution.

Gene Shoemaker was a geologist. What qualifies him to comment on asteroids and comets?

SCSU was a fine school for geology. It was attended by a large number of gold diggers, sent there by poor Connecticut parents, hoping that their daughters would run into and marry a rich Yale guy.

Chad Irby

It’s really interesting, seeing how so many things in geology are being “discovered” by academic geologists after years and years of old petroleum geologists taking them for granted.

Pyrthroes

“If I were riding a light beam and looked back, what would I see?” (attrib. to Albertus Magnus b. 1879, about 1892). The answer is, Specialty Relativity. Next question.

Moderately Cross of East Anglia

As always a fascinating and educational contribution David, thank you.
I am somewhat intrigued by the title picture which appears to show a clear “channel” to the East (as looked at on the picture and assuming the top really is North) but which is not so apparent in the diagram – almost as if there had been an episode of substantial flow breaking through the surrounding rim in this direction. Is this just illusory?

Incidentally, are there any known salt zits that are known to have been blasted by an impact – just to make things really complicated?

Electrical discharge can produce shock quartz.

See:

Generation of shock lamellae and melting in rocks by lightning‐induced shock waves and electrical heating

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL073843

“Our study on rock fulgurites provides an indirect constraint on the energy of a lightning event and also demonstrates that the presence of shock features in rocks cannot be taken as unequivocal evidence for impact events.”

Felix

Right on.

Proponents of the YD impact WAG think they can tell ET shocking from lightning effects, but their special pleading and hand waving aren’t convincing.

HDHoese

You geologists have all the fun. Have looked into and driven through some of these depressions helping understand why I did poorly in hard rock lab. Which reminds me when is your article coming out on Green Schist? Parallel fractures of a sort. As to the elephant it belonged to the blind biologist, at least before simulations.

Good article. Also, Chamberlin’s Method of Multiple Working Hypotheses was picked up by a 1971 water pollution book, not sure they use it so much nowadays.

charles nelson

How very refreshing to see people addressing a real conundrum using actual physical hard evidence without once resorting to averages or statistical filters or adjusted data!
Thank you. I enjoyed that muchly.

Geoff Sherrington

David,
Our corporate seminars often ended with the summary that 50 geologists would produce 50+ competing theories, each one argued conclusively. Geoff

Myron Cook

David,
I really enjoyed your write-up. As a fellow petroleum geologist that has worked salt influenced areas in the Gulf of Mexico, I was always biased towards the salt diapir theory. I have been to this site many times over the years and one simple fact heavily influenced my thoughts; there are other salt related features in the area. In my mind having just two shocked quartz grains seemed a bit weak. This new evidence really is the “smoking gun” for any geologist who understands how salt diapirs form and what the resultant geometries look like. I’m glad this issue has finally been resolved.
Myron Cook

“Did you ever notice how government and closely affiliated academic scientists seem to interpret data with the intent of finding a specific answer, while private sector and closely affiliated academic scientists interpret data with the intent of finding the answer that best explains all of the observations? I notice this all the time.”

Not all the time. Did you notice that Wegener was a government meteorologist at the German Naval Observatory and who was most vocal in rejecting his theory? The American Association of Petroleum Geologists! Are they not geologists from oil companies? They even organized a symposium to reject Wegener’s continental drift theory.

Christy and Spencer were NASA scientists. Jastrow, a prominent climate skeptic, was a NASA scientist and founder of GISS. How ironic!

Kevin Kilty

A long, but comprehensive and interesting contribution, Dave. Thanks for the time you took to put it together.

On the occasion of the 250th anniversary of Ben Franklin’s kite flight (2002), I was asked to contribute something toward the proceedings of a conference held at U. Penn. by a now defunct organization “The Society of Amateur Scientists”. My paper advocated making geology and other historical sciences (even history) look more like experimental sciences. Something I discussed in that talk (and wrote in a subsequent book which is not so good and I don’t recommend) is using a table of contrasts, which is common for designing experiments in engineering and agronomy, but not widely recognized otherwise. The long list of evidence that Martin Jackson made regarding the two leading hypotheses of the time is just about exactly a filled-in table of contrasts. It’s experimental geology! I wish I known of the example at the time–I used some other examples.

By the way, after Alvarez hypothesized the demise of the dinosaurs, and the discovery of the Yucatan crater, there grew a sort of bias of seeing impact craters everywhere, and I had briefly assigned the impact origin of upheaval crater to such. It grew into a sort of “bandwagon” that anyone familiar with history of science will recognize, and that anyone will also recognize as a central feature of climate change science. For another recent example of the bandwagon effect, one might consider R.O.Castle’s Palmdale uplift.

TA

Very interesting article.

I have a question: Why would an eroded salt dome have a raised peak in the center? Is that a normal feature?

Thank you for this wonderful article. The Colorado Plateau and Great Basin regions hold a tremendous amount of geological wonders.
One area regarding a potential biode impact area is just as intriguing is the Alamo impact in Nevada. I’ve done a bit of reading on the potential but due to age and total rearrangement of the landscape solid evidence is lacking. I’d be interested in your opinion on this possible impact area.

Bill

meteorologist in research

The sliding rock mystery has been solved.

From the abstract

The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved >60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, “windowpane” ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of ∼4–5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2–5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0105948

Geoff Sherrington

My former boss, John Elliston, used to demonstrate how thin liquid layers could move heavy objectsmore easily than on dry surfaces. Darin a glass of its cold beer, then upend on a smooth marble bar top. Residual liquid makes a wet layer, some warming post-inversion applied a little help in keeping the contact lubricated and hey presto, you can move it with a rather tiny tilt or gentle push. Strike slips and all that stuff.

You should read John’s new book “The origin of Rocks and Mineral Deposits”, particularly if you have an inquisitive mind like many readers here do. It has the capacity to revolutionize thoughts about geology. However, resistance to new ideas can be expected. John was a great friend of the late Prof Sam Carey of plate tectonic fame, of whom we can read –
“Carey was made an Officer of the Order of Australia in 1977
and became a Fellow of the Australian Academy of Science in
1989. The reason for this late admittance to the Academy is a
long story of misunderstanding due to strong scientific conservatism
among Academy Fellows”
Geoff

Bruce of Newcastle

Nice article David! I’ll add that the Chicxulub impactor in Yucatan apparently landed on a thick layer of gypsum. I don’t see why an earlier impactor could not have landed on a sedimentary precinct containing a layer of halite.

David,

Another fantastic post! I had attempted to write a comment earlier in the week, but the website transition wasn’t agreeing with my devices.

I hadn’t gotten about 50% of the way through the post and the idea that the dome was possibly both things began to creep into my mind. Needless to say, I felt pretty good about myself when I got to the end!

Wakeupmaggy

I recently flew over it and assumed it was an old oxbow. How interesting to read this. I also took pictures of it and he Paradox salt dome area, where the Dolores River cuts across it and has to be desalinated.

Stevan

Dave, I happened to see Upheaval dome for the first time just last year. My pictures clearly showed sedimentary layers in the wall on the far side of the central spike. I wondered at the time how anyone could think those layers could have survived an impact large enough to make such a large “crater”.

SR

William Nicholls

You treat all evidence points as equal. Since there’s no way that shocked quartz and shatter cones can exist there without an impact, those points have far more weight than the other structural clues creatively interpreted. Other evidence you have not discussed includes features like Robert’s Rift, where a powerful force filled a crack aligned with the crater with breccia from deeper formations, and the wet sediment impact interpretation of the rumpled Carmel Formation and evidence of liquefaction of sandstone pipes as described by Huntoon et al. http://www.geosociety.org/documents/gsa/fieldForum/reports/01rpt1.htm