Geologists dig into Grand Canyon’s missing billion years
A new study led by the University of Colorado Boulder reveals the complex history behind one of the Grand Canyon’s most well-known geologic features: A mysterious and missing gap of time in the canyon’s rock record that covers hundreds of millions of years.
The research comes closer to solving a puzzle, called the “Great Unconformity,” that has perplexed geologists since it was first described nearly 150 years ago.
Think of the red bluffs and cliffs of the Grand Canyon as Earth’s history textbook, explained Barra Peak, lead author of the new study and a graduate student in geological sciences at CU Boulder. If you scale down the canyon’s rock faces, you can jump back almost 2 billion years into the planet’s past. But that textbook is also missing pages: In some areas, more than 1 billion years’ worth of rocks have disappeared from the Grand Canyon without a trace.
Geologists want to know why.
“The Great Unconformity is one of the first well-documented geologic features in North America,” Peak said. “But until recently, we didn’t have a lot of constraints on when or how it occurred.”
Now, she and her colleagues think they may be narrowing in on an answer in a paper published this month in the journal Geology. The team reports that a series of small yet violent faulting events may have rocked the region during the breakup of an ancient supercontinent called Rodinia. The resulting havoc likely tore up the earth around the canyon, causing rocks and sediment to wash away and into the ocean.
The team’s findings could help scientists fill in missing pieces of what happened during this critical period for the Grand Canyon—today one of North America’s foremost natural wonders.
“We have new analytical methods in our lab that allow us to decipher the history in the missing window of time across the Great Unconformity,” said Rebecca Flowers, coauthor of the new study and a professor of geological sciences. “We are doing this in the Grand Canyon and at other Great Unconformity localities across North America.”
Beautiful lines
It’s a mystery that goes back a long way. John Wesley Powell, the namesake of today’s Lake Powell, first saw the Great Unconformity during his famed 1869 expedition by boat down the rapids of the Colorado River.
Peak, who completed a similar research rafting trip through the Grand Canyon in spring 2021, said that the feature is stark enough that you can see it from the river.
“There are beautiful lines,” Peak said. “At the bottom, you can see very clearly that there are rocks that have been pushed together. Their layers are vertical. Then there there’s a cutoff, and above that you have these beautiful horizontal layers that form the buttes and peaks that you associate with the Grand Canyon.”
The difference between those two types of rocks is significant. In the western part of the canyon toward Lake Mead, the basement stone is 1.4 to 1.8 billion years old. The rocks sitting on top, however, are just 520 million years old. Since Powell’s voyage, scientists have seen evidence of similar periods of lost time at sites around North America.
“There’s more than a billion years that’s gone,” Peak said. “It’s also a billion years during an interesting part of Earth’s history where the planet is transitioning from an older setting to the modern Earth we know today.”
A continent splits
To explore the transition, Peak and her colleagues employed a method called “thermochronology,” which tracks the history of heat in stone. Peak explained that, when geologic formations are buried deep underground, the pressure building on top of them can cause them to get toasty. That heat, in turn, leaves a trace in the chemistry of minerals in those formations.
Using this approach, the researchers conducted a survey of samples of rock collected from throughout the Grand Canyon. They discovered that the history of this feature may be more convoluted than scientists have assumed. In particular, the western half of the canyon and its eastern portion (the part that tourists are most familiar with) may have undergone different geologic contortions throughout time.
“It’s not a single block with the same temperature history,” Peak said.
Roughly 700 million years ago, basement rock in the west seems to have risen to the surface. In the eastern half, however, that same stone was under kilometers of sediment.
The difference likely came down to the breakup of Rodinia, a gigantic land mass that began to pull apart at about the same time, Peak said. The researchers results suggest that this major upheaval may have torn at the eastern and western halves of the Grand Canyon in different ways and at slightly different times—producing the Great Unconformity in the process.
Peak and her colleagues are now looking at other sites of the Great Unconformity in North America to see how general this picture might be. For now, she’s excited to watch geologic history play out in one of the country’s most picturesque landscapes.
“There are just so many things there that aren’t present anywhere else,” she said. “It’s a really amazing natural lab.”
See more here: phys.org
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Helge Aspevik
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Because the theory is wrong… https://helges-klimablogg9.webnode.com/helge-aspeviks-continental-drift-theory-english-version/
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Jerry Krause
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Hi Helge and PSI Readers,
This comment is mainly addressed to the PSI Readers. For I have tried to discover whom Helge actually is and could not specially find this information. But upon going to his ‘link’ I can assure you that he is a SCIENTIFIC SCHOLAR. His WORK proves that. And I remind you readers that an ACTUAL SCIENTISTS IS NEVER CERTAIN ABOUT HIS/HER CONCLUSIONS.
But if you read this article and read what Helge has written, you will find an example of actual SCIENTIFIC SCHOLARSHIP. For at his link Helge shows a reader photos of the Earth’s layers that many of us have seen due to the construction of roads.
And while I sometimes question time scales of billions of years, I know (because I accept that the geological physical processes described in the first few verses of Genesis had to have taken a long time based upon the SCIENTIFIC PHYSICAL LAWS we have observed. I also read in the HOLY BIBLE that the Earth’s SURFACE was reformed in less than a YEAR which is consistent with the little I have read about CONTINENTAL DRIFT. But Helge, when you wrote: “Because the theory is wrong”,. I have no idea of to what theory you were referring. So could you clear this up for me?
Have a good day, Jerry
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MattH
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Hi Jerry, Herb Rose, and readers.
Here is something I just stumbled across on the BBC in an article about the moon affecting weather. ( I need to learn when to use affect or effect. )
“Scientists from Ohio State University have suggested the switch between El Niño and La Niña may be influenced by a subsurface ocean wave driven by lunar tidal gravitational force. Researchers at the University of Tokyo report that Enso may be predicted by looking at the Moon’s 18.6-year nodal cycle.”
It is comforting when research supports ones own psychedelic rationalization of possibilities.
Have a nice day
Matt
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Herb Rose
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Hi Matt,
Interesting but since the moon’s orbit is as regular as clock work, how do you explain the variability of El Nino and La Nina?
Herb
(Affect causes something to happen. Effect is a result of something happening.)
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MattH
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Hi Herb. I suggested this concept to you a year or so ago and you requested a reference.
It does not make it true but I have not checked the research alluded to.
Cheers Matt.
Jerry Krause
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Hi MattH,
I believe I have finally digested your comment: “It is comforting when research supports ones own psychedelic rationalization of possibilities.”
“Moon’s 18.6-year nodal cycle.” “Intuitive knowledge keeps pace with accurate definition.” (Lewis Elzevir, 1638). You need to define for PSI Readers what this 18.6-year nodal cycle is. And I ask: Could there be an about 9.3-year cycle and an about 56-year cycle???
And you need define the short period (max two year) and somewhat random (no cycle??) El Nino and La Nina events. I can not remember the details of the Enso so you need to define Enso for the Reader (me) so I can know whether it is an “event” or some clearly observed cyclic (repeating) phenomenon with a period of many years.
Let’s explore these NATURAL PHENOMENA which have been observed for how many years???
Have a good day, Jerry
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MattH
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Hi Jerry. I have to go to work without doing further research at this time.
I have previously suggested the 18.6 lunar cycle could influence latitudinal oceanic water distribution and therefore sea level measurements.
I will try and find the research referred to in a day or two.
My use of the word psychedelic was only throw away humour.
Have a good day.
Matt
Jerry Krause
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Hi PSI Readers,
Just as I had to read and reread MattH’s relativity (to Helge’s article on continental drift) short comment to finally become satisfied I saw what Matt wrote; now as I reread Helge’s I must take back some of which I wrote in praise of his scholarship. I point back to 3 of 4 of his first references. Three of the four are from wikipedia where one does not know who is the author of which one reads. But it seems clear to me that Helge accepts the validity of what he reads in the wikipedia articles.
I do read wikipedia and do quote from it when it agrees with that I have read elsewhere from earlier named authors. I have both the 1968 and the 1979 complete Editions of Encyclopedia Britannica.which do identify the authors, whose academic interests are in the field of that which they write. Yes, I know the downhill slide of academic scholarship beginning a little before 1970. Fo I was a chemistry instructor at a small community college when this slide began (1973 to the present.
And it was in the early 1990s when I first read Dialogues Concerning Two New Sciences (Galileo) and Louis Agassiz As A Teacher (Lane Cooper, 1917). Both books which I should have read before I even went to the U of South Dakota to major in Chemistry and minor in education so I could become licensed as a secondary school science teacher. But no-one ever suggested I should read these two books. And it is seldom mentioned that Galileo was a teacher as was John Dalton. Who, using known SCIENTIFIC LAWS established by the reproducible research results of others, finally (1803) convinced the SCIENTIFIC COMMUNITY that the idea of endlessly dividable matter could not explain these LAWS while his theory of atomistic matter could. So in 218 years we have gone from the world of 1803 to world of 2021. Proving the importance of getting rid of wrong ideas.
I remind PSI Readers that a reason PSI was founded was to get rid of the wrong idea of the greenhouse effect of atmospheric carbon dioxide (GHE). Which wrong idea has been allowed to stand since 1896 despite the many arguments of PSI Founders and Readers and my failure to convince the PSI Community that observed fact that the temperature of the Earth’s atmosphere has never been observed (measured) to be less than that of the atmosphere’s dew point temperature measured at the same place and time. Which reproducible measurements establish A SCIENTIFIC LAW. Since the prediction of the GHE idea is that the atmosphere’s temperatures would be 33C (58F) less than that measured if the atmosphere had no carbon dioxide molecules in it, this SCIENTIFIC LAW absolutely refutes the GHE theory (idea) and this is no ARGUMENT
However, a historical fact is that Galileo wrote that observed reproducible experimental results had to be supplemented by arguments. The result of which was that he refused to accept that the astronomical measurements of Tycho Brahe and Johannes Kepler’s rigid mathematical analysis of Brahe’s carefully measured data proved that the planets did not orbit the Sun along the lines of a circle as Galileo believed to be the case. For it is always easy to ARGUE that the data must be wrong. And in the case of Brahe’s naked eye measurements, this could have been, and should have been, a Valid Concern. But with quantitative measurements made with a telescope it soon seen that Brahe’s measurements were accurate enough to establish the validity of Brahe’s measurement.
My essays and comments have been criticized because I appear to ramble. Here I began with a criticism of Helge even though I had not even addressed the comment to him. And I have not yet identified what the most serious problem was (my opinion). It was that Helge, and the authors of Wikipedia articles rewrite history and history is critically important. But to know this one must have experience. Einstein wrote and I agree: “The only source of knowledge is experience.” If you read carefully what Galileo wrote he always acknowledged that his ‘quantitative’ observations uncertain (not exact).
I have read authors who state that Galeleo never observed falling bodies. In other words they call him a liar. For they are probably the ones who have never purposely observed falling bodies.
Now, a historical fact written by Kepler is that it was only when he tried to analyze Brahe’s Mars data as if it followed a circular orbit about the Sun that there was just too much error to explain its cause was experimental error. Now, I do not know how Kepler did his analysis. But I ponder: Wasn’t the Earth’s orbit a critical factor in his mathematical analysis? Hence, before he could analyze the other planets orbit, he somehow had to first determine what the Earth’s orbital path was.
I will fast forward to Kepler’s comments, which I read in the English language and which were that the fit of all the planets were a better fit to an elliptical path than to the previous circular path. That fact pretty much refutes the argument involving experimental error.
I know this is a lousy comment but I am going to submit to just see if it generates any comment. For I have worked more than a hour in trying to compose what I hoped could be simply understood by an inexperienced person. And this has nothing to do with a person’s intelligence and other skills. And I do want a reader to recognize this fact.
Have a good day, Jerry
Have a good day, Jerry
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MattH
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Hi Jerry and Readers.
Here is the reference to the BBC article on lunar influence on weather. It contains some absolute garbage but also some information of value.
This is off topic but relevant to the scientific inquisition.
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MattH
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https://www.bbc.com/future/article/20210820-the-subtle-influence-of-the-moon-on-earths-weather
Jerry Krause
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Hi Helge, Andy-coeditor of PSI, and other PSI Readers,
This comment concerns good, accurate Historical Scholarship.
An general example of such is ‘The Martyrs of Science’ by David Brewster (1840). I discovered this GREAT book of the history of SCIENCE in the state library at Sidney Australia.
A specific example of such is from the actual words of Galileo found in this book. Read and Ponder (Weigh)
“I cannot omit this opportunity to relating to you what happened to myself at the time when this opinion (the Copernican system) began to be discussed. I was then a very young man, and had scarcely finished my course of philosophy, which other occupations obliged me to leave off, when there arrived in this country, from Rostoch, a foreigner, whose name I believe, was Christen Vurstisius (Wurteisen), a follower of Copernicus. This person delivered on this subject, two or three lectures in a certain academy, and to a crowded audience. Believing that several were attracted more by the novelty of the subject than by any other cause, and being firmly persuaded that this opinion was a piece of solemn folly, I was unwilling to be present. Upon interrogating, however, some of those who were there, I found that they all made it a subject of merriment, with the exception of one, who assured me that it was not a thing wholly ridiculous. As I considered this individual to be both prudent and circumspect, I repented that I had not attended the lectures; and, whenever I met any of the followers of Copernicus, I began to inquire if they had always been of the same opinion. I found that there was not one them who did not declare that he had lone maintained the very opposite opinions, and had not gone over to the new doctrines till he was driven by the force of argument. I next examined them one by one, to see if they were masters of the arguments on the opposite side; and such was the readiness of their answers, that I was satisfied they had not taken up this opinion from ignorance or vanity. On the other hand, whenever I interrogated the Peripatetics and the Ptolemeans—and, out of curiosity, I have interrogated not a few-respecting their perusal of Copernicus’s work, I perceived that there were few who had seen the book, and not one who understood it. Nor have I omitted to inquire among the followers of the Peripatetic doctrines, if any of them had ever stood on the opposite side; and the result was, that there was not one. Considering, then, that nobody followed the Copernian doctrine, who had not previously held the contrary opinion, and who was not well acquainted with the arguments of Aristotle and Ptolemy; while, on the other hand, nobody followed Ptolemy and Aristotle, who had before adhered to Copernicus, and had gone over from him into the camp of Aristotle;—weighing, I say, these things, I began to believe that, if any one who rejects an opinion which he has imbibed with his milk, and which has been embraced by an infinite number, shall take up an opinion held only by a few, condemned by all the schools, and really regarded as a great paradox, it cannot be doubted that he must have been induced, not to say driven, to embrace it by the most cogent arguments. On this account I have become very curious to penetrate to the very bottom of this subject.”[6]. [6] Systema, Dial. il. p. 121
Have a good day, Jerry
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Burns Matkin
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I agree with Helge that the theory is wrong. However, I also disagree with the problem with ages of rocks. There is no place on the planet where you can go and find the entire strata of time. Some micro thin layers of dust may represent millions of years and that in itself is just plain stupid.
The grand canyon probably was not formed over billions of years, it was probably formed reasonably quickly in the time scale and that is why there are gaps.
The earth in stasis is really a ridiculous idea. The earth in flux is much more representative of what history we can be reasonably sure about.
If you remove the stasis part of the theory, most of the other theories come crashing down. This is not a desirable outcome to the guess work of “science”.
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LLOYD
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WiKi: Becoming GIGO.
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Herb Rose
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As I understand the theory, the Grand Canyon was formed by the the land slowly rising as the river continued to flow, exposing the strata layers laid down over the ages. If the land had risen quickly wouldn’t the river have changed course rather than creating this deep gorge?
The Dells in Wisconsin are the result of an ice dam breaking and the flood of water producing a shallow gorge.
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Jerry Krause
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Hi MattH and other FSI commenters and Readers.
I have scanned back to this article of 8/24, only 4 days ago. And I find that the information the link (https://www.bbc.com/future/article/20210820-the-subtle-influence-of-the-moon-on-earths-weather) that Matt shared with us has not been discussed at all. I just quickly scanned it and I believe it desires greater consideration. So I will take the time to seriously study it a report back to you.
And hopefully some of you will see this recent comment before it becomes history. But if I find it deserves I will keep referring to it until until I get at least one response from our little group.
Have a good day, Jerry
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Herb Rose
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Hi Jerry,
I think you’ve lost the few marbles you had. The article was published and you, me, Matt, Michael, and others have made multiple comments.
Herb
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Jerry Krause
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Hi Herb,
Thank you for setting me straight!!! You are so right and I do need help to keep me on the straight and narrow. Some day you might get old and better understand my PROBLEM.
Have a good day, Jerry
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Herb Rose
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Hi Jerry,
I am old and experiencing the same problems you are. The only saving game of getting old is that we won’t have to endure the current insanity for much longer.
Herb
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Jerry Krause
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Hi Herb,
Relative to rivers change their course and erosion (both water and wind) I suggest you get and read a very informative book, ‘North Dakota’s Geologic Legacy’, by John P Bluemle, a lifetime field geologist: In fact I would suggest all of you read this book.
Have a good day, Jerry
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