Having had my bum fried several times in rather one sided evo arguements in the spirit of rapprochement I come with some difficult questions that I welcome evolutionists / geologists / anykindaists to provide answers - I'm not trying to prove anyones answers wrong - just to see what we come up with...
What is the geological column? Where do we find it? What evidence is there for it?
Questions for evolution believers - the geological column
by Qcmbr 20 Replies latest watchtower beliefs
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Qcmbr
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peacefulpete
here's a primer of what we should have learned in middle and high school had we been listening.:Geological Time
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bebu
here's a primer of what we should have learned in middle and high school had we been listening.:
LOL! Ain't it the truth.
bebu
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Qcmbr
So the geological column is 'earth's trash can ' the evidence of deposition - each layer refers to large periods of time acurately dated by radiocarbon dating. Places wher the geo column are missing a few million years means they were eroded at that point. Any example of this geological column? Any idea where the eroded material got deposited (would that affect the radiocarbon dates of that new deposit?)
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Robert_V_Frazier
You can see most of it in the Grand Canyon. A mind-bogglingly impressive sight!
Robert V Frazier
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Qcmbr
Doesn't the grand canyon actually miss out chunks of the geo column?
"Two separate geologic stories exist at Grand Canyon. The older story is the one revealed in the thick sequence of rocks exposed in the walls of the canyon. These rocks provide a remarkable record of the Paleozoic Era (550-250 million years ago). Scattered remnants of Precambrian rocks as old as 2000 million years can also be found at the bottom of the canyon. The story these rocks tell is far older than the canyon itself. Mesozoic and Cenozoic rocks (250 million years old to the present) are largely missing at Grand Canyon. They have either been worn away or were never deposited." -
AlanF
Qcmbr said:
: What is the geological column? Where do we find it? What evidence is there for it?
There are actually two working definitions. One is that the geologic column is a theoretical device that allows geologists to correlate rocks in various parts of the world. The other simply means that rocks everywhere form a sequence, pile or column, and this pile or column various from place to place.
Now don't go getting all excited when I say "theoretical", because I don't mean that the geologic column is a product of the fertile imaginations of nasty, atheistic scientists. I mean that there is no one literal "column" that exists in any part of the world that contains all of the rock layers found in all parts of the world. Thus, the geologic column is actually a sequence of time periods in which various kinds of rocks were deposited in sequence. It's a theoretical device that allows rock sequences around the world to be correlated to one another in time. Because the rocks deposited at any given time in a particular region differ from region to region, the exact sequence of rocks naturally differs from place to place. For example, the White Cliffs of Dover consist of chalk deposited in a shallow sea between about 100 and 65 million years ago. This deposit of chalk can be found from Ireland to France, so it's obviously not a global deposit. Clearly then, the actual sequence of rocks in a local, physical geologic column varies from place to place. And by definition, a local geologic column exists wherever there are rocks, so they're found everywhere. The evidence for it is obvious: look at the sequence of rocks.
An analogy is the Periodic Table of Elements. Scientists have put together a complete list of elements along with some of their properties into a regular table. This table is a theoretical device that forms a complete list of the elements in the world. However, if you take samples of rock from various places, you won't find all of the elements listed in the table in every sample. You'll find only a subset of the elements. It's the same with the theoretical geologic column versus a particular local geologic column. The local column will contain only a subset of the full set of rock layers in the theoretical column.
: So the geological column is 'earth's trash can '
That's a reasonable analogy, but quite simplified from the actual situation.
: the evidence of deposition - each layer refers to large periods of time
Correct.
: acurately dated by radiocarbon dating.
No. Radiocarbon dating is good only for about 50,000 years. Rocks are dated by various other radiometric methods such as uranium/lead and potassium/argon. The dating is certainly accurate, because a number of independent methods give generally consistent answers.
: Places wher the geo column are missing a few million years means they were eroded at that point.
More accurately, there are places in every local geologic column where some layers are missing. This is because at times, deposition has stopped and erosion begun. Eventually, deposition began again and deposited more layers.
: Any example of this geological column?
The entire UK is one local example. In fact, it's the first example, since it was British geologists in the first half of the 19th century who first worked out the local sequence of rocks and gave names such as Devonian to various sequences of layers that seemed to form a single unit. In no place in the UK can the entire local sequence be found, but the entire local theoretical geologic column has been pieced together by comparing rock sequences from all over the UK and adjacent areas.
The Grand Canyon region in the US is another example. In the Grand Canyon, you can find many features of a generalized geologic column. At the lowest level you find what's called The Great Unconformity, which is a nearly level suture line between the igneous Precambrian basement rocks and the thick layer of sedimentary rocks above. At various higher levels, you find other suture lines or unconformities between layers. Sometimes these are not continuous, because over the entire region you might see some areas where a particular layer exists and other areas where it's missing. This is because erosion removed all of that layer in some areas but left some of it in other areas. At these suture lines you often find landscapes, complete with rolling hills, streambeds and every other usual geological surface feature. Clearly, at some times the region was under water and received water-laid deposits. At other times it was above the water and either eroded or received windblown deposits such as the thick sandstones that comprise some of the layers.
: Any idea where the eroded material got deposited
Ultimately, the oceans or sinking land areas. For example, the Mississippi River has been depositing massive amounts of material from the continental US in its bed and in the Gulf of Mexico for tens of millions of years. These deposits are up to 20 km thick at the mouth of the river. The Rhone River is another interesting example. It has been dumping sediments from the Alps into the Mediterranean Sea for many millions of years, and there's an extremely thick layer of these deposits at the mouth of the Rhone and extending far out into the sea.
: (would that affect the radiocarbon dates of that new deposit?)
Sedimentary rocks are not directly dated by radiometric methods. Only igneous (volcanic) rocks can be directly dated. Sedimentary rocks are dated by various indirect methods, and sometimes can't be dated well at all because the necessary conditions are not met. This is a large subject and you need to do your own research to understand it.
AlanF
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Qcmbr
OK so the geological column is the theoretical column used to denote depositions at certain times in earths history.
Does the top of a layer - let's take an example - zoroaster granite layer in the grand canyon - show different ages to the bottom? -
AlanF
: OK so the geological column is the theoretical column used to denote depositions at certain times in earths history.
Right.
: Does the top of a layer - let's take an example - zoroaster granite layer in the grand canyon - show different ages to the bottom?Remember the difference between sedimentary layers and igneous rocks. Sedimentary layers, when dateable, always show different ages (occasionally such layers are drastically moved, or even inverted, by earth movements, but these are special cases and usually quite evident), and naturally the younger overlie the older. Igneous rocks like granite are put in place all at once, so there's no layering, and the entire mass solidified at the same time (geologically speaking; it can take many thousands of years for a thick layer to freeze, or even millions in the case of a granite emplaced deep in the earth with thick insulating rock layers all around it; the Zoroaster granite is close to 2,000 million years old and a couple of million years is irrelevant).
AlanF
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Aztec
Okay Alan, when I ask you questions you force me to read but when others ask them you give them a point by point analysis to their queries. So not fair.