Author: Chris Stassen Subject: FAQ: Evaluation of ICR Grand Canyon Research Project [DRAFT

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======================================================================== Author: Chris Stassen Subject: FAQ: Evaluation of ICR Grand Canyon Research Project [DRAFT] Updated: 04/22/94 ======================================================================== NOTE: Austin has promised to publish all of his data at some point, and this work cannot really be completed until that happens. However, since Austin has seen fit to (before publishing a full paper) make all sorts of claims for his results in non-technical literature, this FAQ makes use of the information available at the time of writing. ======================================================================== The Grand Canyon looks something like this: Plateau Canyon \ ________________ _\ /________________ __| /_________________ ___\ /__________________ <-- Paleozoic rocks ____| |___________________ _____\__/ ___________________ ...\ \ \ \ \ \ .... <-- Angular unconformity .....\ \ \ \ \ ...... .......\ \ \ ............ .........\ .................. <-- Metamorphic rocks Steve Austin of the ICR wrote _Impact #224_ (Austin 1991), claiming that he has derived a Rb/Sr isochron "age" for lava flows on the Uinkaret Plateau in excess of 1.3 billion years (several of these flows spill into the canyon). The Cardenas Formation, a tilted layer at the bottom of the canyon (below the angular unconformity) is generally accepted as being about 1.1 billion years in age. Clearly, something is wrong here. Lava flows which spill off the plateau into the canyon cannot be older than the canyon itself. The canyon can't be older than the rocks that it is cut into. The flat sediments can't be older than those below the angular unconformity (as they were deposited on top). Even young-earthers admit the validity of such geologic relationships (though they argue for greatly compressed time-scales.) Austin's apparent thesis: Rb/Sr dating of the feature which must be the youngest gives a value older than that which must be the oldest, therefore the method does not work. (Of course, then, all radiometric results can "justifiably" be ignored.) What is going on here? Has Austin really (as he claims) struck a blow against the "foundation" of isochron dating? Would any (mainstream) geologist have attempted to obtain an "age" in the same manner, or attached the same significance to it? First, let's turn back the clock to _Impact_ #178 (Austin 1988), an earlier paper on the same lava flows. A slightly different "isochron" for the same flows is produced, using data obtained from an earlier study by a mainstream geologist (Leeman 1974). Leeman's paper contains quite a bit more data (with a lot more "scatter") than are reproduced in _Impact_ #178. Leeman's entire data do not fit well enough to an isochron line to lead any geologist to expect the resulting "age" to be reliable. However, when the data are narrowed down to a small range of stratigraphic positions, the remaining data points fall relatively near an isochron line. However, the same stratigraphic data (as used for the selecting process) clearly indicates that the flows did not all occur at the same time (the flows fall into two different stratigraphic "stages", according to _Impact_), one of the requirements of isochron dating is ignored right from the start. The resulting "age" might have significance -- as the age of the common source material for all of the flows -- but it clearly cannot be used to date the flows themselves (the geologic evidence indicates that there IS no single common "age" for all the flows). In fact, this sort of "pseudo-isochron" is documented in the mainstream literature and is relatively well-understood. _Impact_ #178 even contains two references to the mainstream explanation for such an "isochron," one of them being (Faure 1986, p. 147). Now, back to _Impact #224_ (Austin 1991), which contains an "isochron" constructed from rock samples taken by the ICR. The same lava flows as selected from Leeman's paper in _Impact #178_ are used, but (suspiciously) any mention of the "mainstream" explanation for the "pseudo-isochron" has been dropped and two important claims are made: 1) The "isochron" is claimed to be "unexpected." (This is clearly false, as the paper trail -- _Impact #178_ -- shows that Austin knew he'd get a pseudo-isochron long before the ICR obtained a single rock sample of their own.) 2) The "isochron" is claimed to apply to the flows themselves. (This is clearly false, for reasons described above.) Those claims form the basis of the key criticisms of the "Grand Canyon Dating Project." 1) If Austin wished to -- as he claims to -- "test" Rb/Sr dating, why did he have to "rig" the test by performing it on a formation where the result was known in advance? Perhaps even he knows that Rb/Sr dating produces values convenient to mainstream expectations most of the time? 2) Austin's attempt to apply the dating method is obviously bungled, and the basis of the error is openly admitted in print. No geologist would construct an isochron plot from samples of differing stratigraphic positions and expect the resulting "age" (if the data points did fall on a line) to represent the age of each individual formation. Austin, 1992, "Excessively Old ``Ages'' For Grand Canyon Lava Flows", _Impact_, Number 224, February. Austin, 1988, "Grand Canyon lava flows: A survey of isotope dating methods", _Impact_, Number 178, April. Faure, 1986, _Principles of Isotope Geology_ Second Edition. ISBN 0-471-86412-9. 589 pp. Leeman, 1974, "Late Cenozoic Alkali-Rich Basalt from the Western Grand Canyon Area, Utah and Arizona: Isotopic Composition of Strontium", in _Geological Society of America Bulletin_, Vol. 85, November, pp. 1691-1696. ========================================================================


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