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Author Topic:   Unconformities and the age of the Earth: Challenge to Anti-Climacus and other YECs
Harlequin
Inactive Member


Message 1 of 3 (173068)
01-02-2005 2:26 PM


Anti-Climacus in Message 102 of the "Radiometric Dating and Geologic Column: A Critique" clearly thinks that mainstream science advocates should be surprised that there are gaps of millions of years between strata. He acts as if that "recent" strata immediately on top of Precambrian strata is clear evidence against mainstream geology instead of something which should be expected.
Well this brings up a series of questions that I have for Anti-Climacus and any other YEC who uses such arguments:
All of what I described, acting in the past, would have resulted in what geologists call unconformities. Their significance for the age of the Earth was recognized by James Hutton in the 18th century. Here is an illustration of the Hutton Unconformity in Jedburgh, Scotland illustrated by John Clerk in 1787:
This type of unconformity is called an angular unconformity for obvious reasons: two sets of strata are at angles to each other. This is a rather extreme case in that one set of layers is nearly vertical and the more recent strata is horizontal.
What must happen for such a thing to form? At the very least: stata was laid, strata got tilted and eroded, new strata was laid, and if it is exposed then it must have been eroded yet again. This is very simplified: I could have mentioned several cases which land was uplifed and/or sea level lowered. This series of events makes a young-Earth seem unlikely. As we will see, we can change unlikely to flat out false. In any event, the main lesson here is that where there is an angular unconformity there is a gap in the stratagraphic record. We know this to be true without any sort of reference to evolution, fossils, or radiometric dating.
The Grand Canyon has a rather famous angular unconformity called the Great Unconformity. It also has many other unconformities. Lets look at a diagram of several types of unconformities found at the Grand Canyon. (The diagram does not show all the unconformities present.)
Source of image: Images for a Duke University Geology Course
The "NC" stands for nonconformity. A nonconformity is an unconformity where strata meets rock that is not layered as this diagram of a typical nonconformity shows:
To form this the non-layered rock was eroded and strata was laid. (For the nonconformity in the Grand Canyon one could point out that even before all this happened that the intrusions must have formed first before the erosion but that is getting a bit off-topic....)
"LU" stands for local unconformity:
Local unformities are small (or relatively small) remains of a series of strata that was removed by erosion in most places leaving only a little bit left. This sort of thing is even worse for YEC then angular unformities since it requires an additional cycle of erosion and deposition. Again the extremely simplified outline: strata laid, strata eroded, strata laid strata eroded, strata laid, and--if exposed--strata was eroded. The Temple Butte limestone is a local unconformity in some areas of the Grand Canyon. The Surprise Canyon Formation also is sometimes a local unconformity at the Grand Canyon.
Now this is where my question of why we should be surprised to find "gaps" in the stratographic layer should really start biting. I so far have shown (not assumed) that there are six "gaps" the Grand Canyon's record. Again we did not need evolution, fossils, radiometric dating, or even unformitarianism for this demonstation. To make these gaps we, umpteem cycles of deposition and erosion are required. And it is about to get a whole lot worse.
The final type of unconformity we will discuss is the disconformity which was what the "D" stood for:
It is like an angular unconformity except there was no tilting so they are not nearly as obvious. YECs usually claim that disconformities are only an attempt to explain away missing geologic periods. This is outright false. Notice in the diagram above that the strata above and below the disconformity are horizontal -- they are parallel. But also notice the disconformity in that diagram is not parallel. This is often the case. This sort of behaviour is what gives unconformities their name: the two sets of strata often do not "conform." (This is actually the case for the other types of unconformities discussed above as well.) Because they do not conform, a detailed examination of the strata can reveal them without any reference to evolution, fossils, or radiometric dating. There are a good number of these in the Grand Canyon. If one accepts their existence then one must also accept the existence of more gaps and more cycles of deposition and erosion are required to explain their existence. So lets show that they really do exist.
Actually we already have demonstrated that disconformities exist since it should be obvious that a local unconformity is nothing more than two distinct disconformities. This might hint to alert readers why unconformities do not conform: deposition of new strata does not always occur on top of completely flat surfaces. Also the type of strata being deposited might be different from what it is being deposited on. So imagine deposition on a non-level surface: lower areas are more likely to have strata laid on them then higher levels. The lower levels will tend to be filled first before the higher levels are covered assuming that they are covered at all.
One sort of thing which would clearly demostrate the existence of an erosional surface, which must have existed if the alleged disconformity really is an unconformity, is the remains of rivers. Rivers will carve a channel in the surface that later got filled in. These channels might have deposits typical of river in them as well. Demonstrating the existence of such an ancient river is one way to demonstrate the existence of a disconformity and thus requiring the additional cycle of deposition and erosion to explain it. What is even worse for the YECs is that it also indicates that it not the case that a single flood creating all of this (though it should have already been clear that is not the case). So lets go to actual evidence.
The Supai Group of the Grand Canyon by Edwin D. McKee which is Geologic Survey Professional Paper 1173. Since the scan is large I will link to it rather than placing it inline:
McKee Figure H7 on page 167. (Please examine figure before continuing to read.)
I dare the YECs to explain to me why I should not accept those as clear cut erosional surfaces and hence clear disconformities and hence real gaps in the stratographic record. (More such figures from McKee can be scanned if any YEC wants for examples.)
McKee identifies six such erosional surfaces in and bordering the Supai Superformation of the Grand Canyon -- and there disconformities elsewhere: the Temple Butte limestone discussed early for example. In any event between this post and the McKee document cited, we now have 12 distinct unconformities in the Grand Canyon. There is also one between the Kaibab Limestone and the Toroweap Formation.
Again this brings up the question of why we are supposed to be surprised that there are gaps? We can see for ourselves with no reference to evolution or fossils that there are none. I must stress this even at the risk of sounding like a broken record. And it also needs no reference to "uniformitarianism" unless assuming that God is not trying to trick us believing in an ancient earth counts as "uniformitarianism."
The Grand Canyon is not the only place to find such features. Look at this river channel:
Buried river channel
Glenn Morton explains this:
quote:
Three dimensional seismic data has been utilized in the past few years in the search for oil. When displayed along a reflector, interesting geologic features are found buried deeply in the earth. Below is a river channel which is buried at a depth of 1670 feet deep under the Texas prairie in Baylor Co. Texas. If all the geologic strata were deposited in a global flood , then this can not be a preflood river channel since there are about 5,000 feet of other flood sediments underneath this river. The white is a limestone in which the river eroded its channel (dark). Oil wells drilled outside of the channel find limestone at this level, but wells drilled into the channel fail to find any limestone here but instead find the sands and shales deposited by the river. The erosion of the limestone requires a lot more time than the young earthers will allow. ( The original can be seen in AAPG Explorer, June 1993, p. 14)
Source: Young-Earth Arguments: A Second Look.
Do notice the river channel meanders which requires a gently flowing river and takes time. Just as important: from this we know there is at least unconformity down there and hence we know there is a gap in the record down there.
As one notes the existence of such unconformities, the sequence of events required to produce the feature becomes more and more complex and requires more and more time. This in and of itself makes an Earth younger than ten-thousand years absurd even without looking at the loads of evidence which belong in other threads: the fossils, radiometric dating, that the Grand Canyon has strata clearly originating different types of enviroments, etc., etc., etc.
To sum up, I have demonstrated that we should expect gaps to form in the here in now and that the evidence is clear -- without the use of fossil, evolution, or uniformitarianism -- that real gaps have formed in the past as demonstrated by indisputable unconformities. Thus any claim that such gaps are evidence against mainstream geology simply false and shows a complete lack of understanding of geology.
Anti-Climacus, it's your move: it is time to justify your unsupported claims that that mainstream geology should not expect to find extensive gaps and explain why what I have provided is not conclusive evidence that such gaps are quite real. If you cannot, then you should withdraw your claim and repudiate the YEC source(s) you got this absurdity from and not use it (or them) in the future.

AdminJar
Inactive Member


Message 2 of 3 (173073)
01-02-2005 2:38 PM


Thread copied to the Unconformities and the age of the Earth: Challenge to Anti-Climacus and other YECs thread in the Geology and the Great Flood forum, this copy of the thread has been closed.

AdminJar
Inactive Member


Message 3 of 3 (173074)
01-02-2005 2:38 PM


Thread moved here from the Proposed New Topics forum.

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