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Veteran Member
Join Date: Mar 2001
Location: Louisville, KY, USA
Posts: 1,840
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Thanks for posting this link. It gives me another opportunity to show just how untenable flood geology explanations of the geologic facts really are.
Regarding the hypothesis that the trackways in the Cocoino were deposited subsqueously, this can safely be rejected, since it is completely at odds with the sedimentary evidence. Let's examine some of this "startling evidence" for the flood. From my article on the Grand Canyon strata:
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While virtually all geologists who have studied the Coconino agree that it is an eolian deposit, creationists have argued that the Coconino dunes may in fact have been subaqeously deposited. An examination of this "evidence" reveals it weakness.
Leonard Brand has argued for a subaqeous origin based on trace fossil morphology (Brand, 1978; Brand and Tang, 1991). Brand points to vertebrate tracks which abruptly change direction, and other tracks which move transversely up the dune faces. Brand interprets these in terms of similar subaqeous tracks made by modern amphibians. Lockley, however, points out that there is no good evidence that these tracks were made by amphibians in the first place, and that more recent ichnological work attributes them to early Caseid reptiles, and that some modern reptiles have been observed running up dunes with an obligue orientation. Lockley (1995) states:
"The weight of biological and paleoenvironmental evidence pertaining to the Coconino sandstone . . . strongly argues against a subaqeous origin for the tracks. There is very little evidence to suggest extensive bodies of water in Coconino deposits. Even those who support the swimming interpretation for Laoporus tracks cannot show conclusively that these vertebrate trackmakers were amphibians or that dry-land explanations must be abandoned" (p. 44).
And in 1999:
" . . . we should state clearly that the evidence for flooding is nonexistent. The protomammal tracks [in the Coconino - ed] are often found in association with with countless trackways of spiders, scorpions, and other desert arthropods that could not have been walking around underwater" (p. 69).
Interestingly enough, Brand (1996) himself wrote in the conclusion of a 1996 paper that: "The data do suggest that the Coconino Sandstone fossil trackways may have been produced in either subaqueous sand or subaerial damp sand" (Variations in salamander trackways resulting from substrate differences. Journal of Paleontology 70, 1004-1010). So, Brand's work, even taken at face value, does not necessarily indicate that the substrate was deposited subaqeously, as flood geologist frequently claim.
Of course, even if Laoporus tracks were interpreted as being impressed into a wet substrate, this would not necessarily indicate that the substrate itself was subaqeously deposited, much less that it was deposited by Noah's Flood! In fact, as we've already seen, the other surface features found in the Coconino -- delicate spider and other invertebrate tracks, raindrop impressions [!], complete lack of marine fossils (brachiopods, radiolarians, hyoliths, etc.) or trace fossils of marine organisms, even though underlying and overlying strata are rich in marine fossils -- argue strongly against this theory. Lockley (1999) notes that "a gentle and subtle mechanism is required, for heavy rains or catastrophic biblical floods would simply wash away delicate tracks of spiders and scorpions. One possibility is dew and the condensing of fog and mist onto track surfaces, as is common in coastal dunes in the present day Namib desert" (p.76).
Indeed, the type and distribution of trace fossils in the Coconino argue strongly against Austin's theory. If you look lower in the Grand Canyon at the Tapeats Sandstone, which IS a shallow marine deposit, you find both (locally abundant) marine fossils *and* marine trace fossils and burrows, for instance the U-shaped burrow diplocraterion, the vertical burrow skolithos, plus several varieties of horizontal trace fossils and trails, including cruziana, which is a trilobite trail. You find none of this in the Coconino, despite the fact that many delicate arthropod trails of spiders and so forth ARE present and fairly common!
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The alternative explanation of the Coconino offered in the AiG article is Austin's sand wave theory. Once again, this "startling evidence" for the flood is startling only in its weakness:
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The subaqeous sand-wave theory promoted by Austin (1994) is rendered dubious on other sedimentologic grounds as well, which overwhelmingly support the eolian interpretation. For instance, whereas the angles of cross-beds in subarial dunes frequently exceed 25-30 degrees, sand waves possess very low angle cross-beds, deviating from the horizontal by about 1-10 degrees. One of Austin's own sources, Allen, writes:
"We cannot emphasize too strongly that sand waves possess low to mild slopes ... it is clear that the sides of the waves rarely dip more steeply than 10 degress overall and can slope as little as 1 degree ..."
The bedforms are also inconsistent with subaqeous deposition. Middleton et al. (p. 195) write:
"The low height-to-wavelength ratio of the wind ripples as measured in plan view exposures of many foresets is consistent with those recorded from modern coastal and inland dunes."
Cuffey notes:
"Careful examination of modern dunes [such as the Great Sand Dunes, White Sands (Collinson, 1986b), Monahans Sand Hills, Nebraska Sand Hills (Ahl brandt & Fryberger, 1982), or on Padre Island (Brookfield, 1984)] indicates that climbing translatent strata, with coarsening-up laminae and rare foreset laminae, form only by the migration and accretion of low amplitude wind ripples in eolian environments (Hunter, 1977; Kocurek & Dott, 1981). Such strata and ripples are ubiquitous in the [Coconino,] Navajo, Entrada, and similar sandstones (Kocurek & Dott, 1981), contradicting a subaqueous origin. Modern eolian sand dunes exhibit internal cross-bedding that is remarkably similar to that in the Colorado Plateau sandstones" (Ahlbrandt & Fryberger, 1982, p. 19; McKee & Ward, 1983, p. 147; Collinson, 1986b, p. 104).
Ralph Hunter, in his classic 1977 paper on the characterisitics of aeolian dune deposits (Basic Types of Stratification in Small Eolian Dunes, Sedimentology, 24, p. 371), wrote:
"Because eolian climbing-ripple structure is generally so different in appearance from subaqueous climbing-ripple structure, a new terminology has been developed. The name, 'climbing-ripple structure', is proposed for any structure formed by climbing ripples, whether or not ripple-foreset cross-stratification is visible. Climbing-ripple structure is potentially composed of wavy layering parallel to successive rippled depositional surfaces and even layering parallel to the vector of ripple climb. The former, called 'ripple laminae superimposed in rhythm' by McKee and here called 'rippleform lamination', is not present, or at least is not visually detectable, in amny eolian climbing-ripple structures. The latter, formerly called 'pseudobedding', 'climbing-ripple stratification', or 'climbing-ripple pseudo-stratification' , is here called 'climbing translatent stratification.' "
The Coconino covers a huge portion of the southwest. The volume of mature quartz sand found in these deposits is immense. In order to account for the Coconino as a rapidly formed "flood deposit," we must assume that it was transported by extremely fast water currents. But how are delicate tracks to be preserved in the midst of such strong water currents? Even if we assume that the Coconino sands were transported by a succession of discrete current pulses, and that vertebrate trackways were made between pulses, it seems likely that each new set of tracks would be destroyed by each new pulse, with little or no net preservation.
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Interestingly enough, even other flood geologists have critiqued Austin's 'Sand Wave' hypothesis. Michael Robinson, for instance, wrote the following in a CEN article:
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"The tracks in the Coconino Sandstone of the Grand Canyon illustrate a related point. The formation belongs to the Permian system, more than half way up the geological record, and according to Brand, some of the tracks appear to have been made by tetrapods moving up the slopes of sand waves
under water. Because of the angle of the cross-beds, which indicate dune heights of 10-18 m, Austin et al. Have concluded that the tracks were formed under 54 m of water by amphibians attempting to reach higher ground during the Flood. The current speeds are estimated to have been over 90 cm per second. . .
If the Hermit and Coconino Formations represent the deposits of Flood waters as they encroached upon the land, how is it that immediately beneath the Hermit Formation we find sediments thousands of feet thick which must also be ascribed to the Flood? If the Permian marks the point in Arizona where the sea transgresses onto the land, why are the deposits beneath the
Permian not all considered pre-Flood deposits? In practice, Austin et al. Argue that the Flood waters reached Arizona as early as the Lower Cambrian. The Hermit and Coconino Formations must therefore have been laid down after Arizona was submerged, and the presence of tracks at those levels is more problematic than they suppose."
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Robinson, 1996. Can Flood Geology Explain the Fossil Record? Creation Ex Nihilo Technical Journal 10, p. 50.
Yet another question is, where are the marine fossils and microfossils? Plenty of delicate arthropod tracks, but no foraminifera, no bivalves or brachipods, no crinoid columnals, no trilobite traces, etc. We know that the preflood ocean had to have been chock-full of this stuff, becaus there is such a huge volume of it in the fossil record. Yet, somehow these currents were powerful enough to sweep sand waves inland over a large portion of north america, did not transport shelly marine organisms also? More oddly, marine strata both above and below the Coconino contain abundant marine fossils? Makes no sense at all on a sand wave theory.
Patrick
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07-22-2003, 10:31 PM
