[QUOTE]Originally posted by TrueCreation:
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1. There are eolian [I have since learned that Aeolian is the preferred spelling] and water-deposited layers intermixed throughout the entire several hundred feet of the Supai Group. The eolian deposits are from the water deposited layers drying, becoming lithified and then being eroded by wind with the resultant sand redeposited, and relithified. This happened repeatedly. How do you reconcile your rapid erosional model with the facts of the Supai deposition?"
--Might you have an example or a cut section of the supai group which indicates the format of this intermixing through the entire several hundred feet? Or at least an illustration of this observational characteristic. Also, what is the indication of them having to lithify, erode, deposit, and then lithify again (most importantly, the indication that it has lithified prior the next deposition). I also have no problem with erosional processes weathering strata as the Geologic Column were deposited, it wasn't just a one go deposition.
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I don’t have the time for a detailed response to your entire post. Also you should know that I am not a geologist, just a dumb assed engineer with a layman’s interest in the C/E debate and specifically in geology. You should probably take that into consideration when evaluating anything I have to say that is not referenced.
You can try here for a detailed mainstream description of the depositional environments responsible for the strata that make up the walls of the Grand Canyon. I would check some of his references for the information you are seeking.
http://www.geocities.com/earthhistory/grand.htmA couple of quotes from that website:
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Above the Watahomigi Formation lies the Manakacha Formation (150-300ft). The Manakacha primarily consists of quartz sandstone, with intercalated layers of mudstone. Of special interest within the Manakacha are layers of cross-bedded, reversely graded sandstone laminae referred to as "climbing translatent strata." Blakey writes that "climbing translatent strata are thin laminae, generally less than several millimeters thick, that display reverse grading within each lamina. Each lamina displays the migration record of a single wind ripple (Hunter 1977) and, as such, is a powerful indicator of eolian deposition" (p. 154). While cross-bedded sandstone can and does form subaqeously given the right environment, no marine sandstones are known contain these structures, which can be observed forming today in dune environments, and nowhere else. At least three units within the Manakacha Formation are thought to have been formed by subarial, eolian processes
The Hermit Formation overlies the Esplande Sandstone It consists of, variously, ripple marked sandstone, occasional outcrops of eolian sandstone, carbonate rich lime, and mudstone. Blakely notes that "The bulk of the Hermit in eastern and central portions of the Grand Canyon consists of weak, ledge-forming, silty, faintly ripple laminated sandstone and slope-forming mudstone. Generally, ten to fifteen cyclic alternations of these units are present" (p. 177). These cycles may be related to tectonic or climatic changes, which have produced similar sequences in easily-datable Cenozoic deposits.
One of your questions was: Also, what is the indication of them having to lithify, erode, deposit, and then lithify again (most importantly, the indication that it has lithified prior the next deposition). We have several layers of sandstone on top of which are cross-bedded Aeolian deposits. How can we have the cross bedded deposits unless the underlying material is hard? Also one might ask, what is the source of this wind deposited sand? The most reasonable source is erosion of the sandstone layers. This is confirmed due to the similarity to the underlying water deposited sandstone. How do we know that it is wind deposited sand? See above for one reason, another is that there are geochemical, grain size and mineralogical analyses that are used to identify Aeolian sand. One of the geologists here can steer you to more details on the techniques I’m sure.
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"2. There are more than a hundred and fifty lava flows from the Kaibab Volcanic Field cascading over the North Rim and down into the canyon. At least a dozen of these flows definitely dammed the river for some period of time. A lake formed upstream of each dam, which took some time to fill with water and more time to fill with sediment. When each lake had filled completely with sediment, the water could flow unimpeded again, and rapidly eroded a new river channel through the remnants of the lava dam.
http://my.erinet.com/~jwoolf/gc_canyon.html If you add up the times necessary to fill each of these lava dammed lakes with water and sediment you get upwards of 4000 years. That is assuming that they happened in rapid succession of each other (the best case scenario for your model). Now how does your rapid erosional model account for the sequential volcanic damming of the river and the times required for the lakes to fill and begin to overflow, breaking down the dams?"
--Just about every geologic process including erosion you will find has a catastrophic characteristic to it in Flood Geology rather than gradualistic deposition or erosion. Conventional Uniformitarianism essentially does not even imply all gradual process but may as well contain extremely catastrophic depositions and erosional evolution. These thoughts on the many lava flows from the kaibab volcanic field are a nice consideration. You wouldn't happen to have access to information on the stratigraphic and topographic features of the existing remnants of the volcanic flows would you?
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Indeed the formation of lava dams and subsequent breaching of the dams would in my mind be catastrophic events. The thing you need to take into consideration is that these were sequential events. Your model needs to reflect this. Did this all happen during one catastrophe or during multiple catastrophic floods? If one flood then I think that you have problems reconciling the data. If many then you need to identify some diagnostic feature that would indicate that this happened. (See later links about the Washington State Channeled Scablands.) Sorry, can’t help you on your data request. I recommend that you chase down some of the references used in some of the links I provided.
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--I read the link you gave, very interesting and insightful. I do not have access to Austin's book for his theory on the Canyon formation. Mine was conjured up on my lonesome, though it seems theirs is relatively similar with the possible exception of time frames and water sources. His theory on the water resource seemingly I would like to look at, I have been unable to give good detail on this because of our lack in information regarding lithologic and hypsographic mapping information for the area. I have had the hunch that grand-lake may not be sufficient in being the source of the actual canyon carving, but may be the proper proponent for stage two of the event (ie, meandering formation prior the catastrophic emptying of other reservoir(s) [See post #93].
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What catastrophe did the canyon carving? According to your model the flood deposited the stuff. Some unknown process caused it to lithify more rapidly than current geology would expect. Then I thought the lake emptying was the event that caused the canyon formation. You had a little stream that began with a little canyon, but why wasn’t that little canyon wiped out by the catastrophe of the lake emptying? I would think that is the most likely scenario. (See later links about the Washington State Channeled Scablands.)
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"3. How does your scenario account for the portions of the canyon through granite? How was the granite deposited during the flood and then how did it get eroded so deeply in such a short time period."
--A question, how was this statement substantiated:
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Go to your kaibab.org site and look at the map. A good portion of the canyon is through granite. In face that section is called granite canyon.
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--Also, we have a couple thousand years of erosion after the grand canyon's formation which may account for the Vishnu Schist erosion. I may also be speculative on the speed of lithification of granite, though I wouldn't put too much confidence in that.
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I’m not sure that talking about the lithification of granite is correct. Lithification is defined in the evcforum geology glossary as: The processes by which sediment is converted into sedimentary rock. These processes include cementation and compaction. Granite is not sedimentary rock. A good place to learn a little bit about granite and the problems it causes for YEC interpretation of geology is here:
http://www.csun.edu/~vcgeo005/miracle.htm. Maybe this can be your next project.
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"Some questions strictly on erosion you need to be able to answer are:
1. How come the GC does not look like any of the examples of rapidly eroded canyons caused by catastrophic emptying of large bodies of water?"
--I can predict that it is because we have a vastly different event and characteristical environmental conditions we are dealing with. But you wouldn't happen to know of another which we can compare and contrast to?
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The scablands of Washington State are an example of what happens when you have a large lake catastrophically empty. This looks nothing like the Grand Canyon.
http://ewu63562.ewu.edu/map.htm has a relief map of the channeled scablands. The following link has a nice space shuttle pic.
http://www.l3-lewisandclark.com/ShowOneObject.asp?SiteID=33&ObjectID=287From that link:
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The agents of removal were gigantic floods originating from a huge glacial lake in northern Idaho and Montana. The lakeLake Missoulaformed behind ice dams near modern Lake Pend Oreille in Idaho and extended back into western Montana. During cold periods the ice sheet advanced southward, forming the ice dam. The waters of the Clark's Fork River then created a lake behind the dam. When the lake became deep enough, the ice dam floated off its foundation and collapsed, unleashing catastrophic floods that ripped enormous channels through the loess and rock of the Columbia Basin.
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"2. How were the side canyons formed at right angles to the flow of water from your hypothetical lake? How can they look similar to the GC, cut the rocks the same way, yet be not be in the direction of flow of the event that formed the GC?"
--Because of the format by which it eroded when water emptied through the grand canyon. Side canyons are most apparent in the north section of the Grand canyon than the south, seemingly austin may have something on this as one of his resources drained into the Grand canyon from a northward perspective. Latter erosion then further created the rougher terrain of the side canyons.
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I’m sorry, but this seems right hand wavy to me. From this map
http://www.kaibab.org/gc/maps/gcmap.htm it seems to me that there are quite a few side canyons on either side of the main canyon.
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Sorry you lost your files. I’m enjoying the conversation, but will be an infrequent contributor. If I do not answer for some time (or at all) it is because of life instead of lack of interest. Good luck in your studies.
Joe T. (not the one currently posting on talk.origins)
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