Source: http://talkorigins.org/faqs/helium/appendixc.html
Timestamp: 2019-04-25 04:15:18+00:00

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Young-Earth creationist (YEC) Dr. D. Russell Humphreys recently posted another insufficient reply (Humphreys, 2006) to my criticisms of his RATE project. Rather than engaging in responsible science, Dr. Humphreys has simply ripped off another rash and superficial note that fails to provide the required evidence to defend his "creation model" and its ridiculous "creation date" of 60,000 ± 400,000 years (2 standard deviations). Instead of relying on evasion and ridicule, Dr. Humphreys needs to take some time (many months and not just hours or days) to actually think about the numerous problems in his work. To begin with, the "dating" equations in Humphreys et al. (2003a) are based on many blatantly false assumptions (isotropic diffusion, constant temperatures over time, etc.) that cannot be dismissed with any claims of "generosity" to the "uniformitarians." Also, the vast majority of Dr. Humphreys' critical a, b, and Q/Q0values that are used in these "dating" equations are either missing, poorly defined, improperly measured or inaccurate. For example, he should stop picking and choosing from the obviously questionable data in Gentry et al. (1982a) and instead take several months to redo the analyses. Dr. Humphreys must further realize that the uranium and thorium data in Gentry et al. (1982b) indicate that his Q0 is far too low and that his Q/Q0values are probably inflated by at least an order of magnitude, which by themselves invalidate his YEC agenda. Rather than ignoring the problems or relying on invalid assumptions about the concentrations of 3He, 4He, uranium and thorium in his zircons, Dr. Humphreys actually needs to perform some detailed analyses similar to those in Gentry et al. (1982b). Extraordinary claims demand extensive and high quality data, which Dr. Humphreys currently doesn't have.
Contrary to claims in Humphreys (2006) that my November update is "rehashing" and has a lack of "substance", anyone can review the diagrams, tables and text in my update and realize that I have raised many new issues and properly reemphasized countless other critical problems in Dr. Humphreys' work, which he continues to unjustifiably belittle and ignore. Just as he did in Humphreys (2005), Dr. Humphreys in Humphreys (2006) believes that he can just read brief snippets of my detailed evaluations of his work, throw out some insults, try to trivialize his serious mistakes, repeat false claims, misrepresent critical details in the literature, invoke several irrelevant analogies, ignore the details, and then hope that his readers will just accept whatever he says and go away. Now, some individuals might accept this type of arm waving, the invoking of "God did it!", and the brushing off of serious criticisms, but real scientists and editors of scientific journals would not. Dr. Humphreys needs to overcome his denial and answer the questions, defend the details of his claims, and fully admit and correct his mistakes. To illustrate the long list of serious flaws in Dr. Humphreys' work, I have summarized some of the problems in my Appendix D.
Dr. Humphreys' work is a prime example of fallacious reasoning that YECs (e.g., Woodmorappe, 1999) falsely accuse geochronologists of using. Because his bogus calculations and inaccurate data just happened to spit out a meaningless number that he likes (6,000), Dr. Humphreys is more than willing to ignore and inappropriately dismiss any data or criticisms that expose the fraudulent nature of his "creation date."
If Dr. Humphreys really wants respect from scientists, he must actually publish something in an AUTHENTIC PEER-REVIEWED science journal and not just Sunday School materials (e.g., Humphreys, 2003) and YEC tabloids (e.g., Creation Research Society Quarterly [ CRSQ ]), where other RATE members and YEC officials will readily rubber stamp anything he says and suppress criticisms of his work (for example, not publishing or referencing the actual statements from an anonymous critic of Dr. Humphreys' work, which are referred to in Humphreys et al., 2004).
Despite the clear statements in my original March, 2005 essay, I had to place this pressure issue prominently in a figure in the abstract of my November, 2005 essay before Dr. Humphreys (2006) even took notice. Again, this demonstrates that Dr. Humphreys does not carefully and appropriately consider scientific evidence and discussions from his critics. Instead, he prefers insults, flippant "answers," and groundless ad hominem innuendo about my former religious beliefs (i.e., Humphreys, 2005). If Dr. Humphreys wants to demonstrate that pressure has no effect on the position of the DEFECT LINE of his zircons and supports his "creation model", he NEEDS to stop arm waving, calling on me to do his work for him, and be responsible and do the experiments himself.
Dr. Humphreys' essays need to discuss how subsurface pressures and long-term exposure to extraneous helium might affect the vacuum-generated DEFECT curve that coincides with his "creation model" (see my Figure 7). Instead, Humphreys (2006) simply cites some information from a small number of articles that either have absolutely nothing to do with the diffusion of noble gases (helium and argon) in silicates (i.e., self-diffusion of lead in Hudson and Hoffman, 1961) or only apply to noble gas diffusion on high-temperature INTRINSIC curves, which are not relevant to the low-temperature DEFECT line of his zircons and his "creation model." In most of the discussions in Humphreys (2006), Dr. Humphreys invokes invalid analogies and makes simplistic and unrealistic statements about "hard" minerals supposedly not being affected by pressure. For example, when Humphreys (2006) refers to the diffusion of argon in the glasses of Carroll (1991, p. 160), he forgets that this reference is dealing with argon diffusion over a relatively small pressure range of 1179 to 3725 bars on AN INTRINSIC CURVE. Unlike Dr. Humphreys, Carroll (1991) makes no irrational extrapolations between vacuum-generated results and high-pressure subsurface conditions. Furthermore, unlike Dr. Humphreys' zircons, the bubble-free rhyolitic glass in Figure 4 of Carroll (1991, p. 161) shows no defect curve. Considering the relatively small pressure range and that the glass was free of bubbles and other defects, it's not surprising that the pressure effects in Carroll (1991) were minor, only involved an intrinsic curve, and do not support Dr. Humphreys' YEC agenda.
While Humphreys (2006) proclaims that zircons are hard and incompressible, he fails to recognize that his zircons are full of potentially compressible defects and glassy metamict regions. Many of these defects are clearly seen in photographs in Dr. Humphreys' articles and even on the cover of the June, 2004 issue of the CRSQ .
The diffusion results in Dr. Humphreys' studies were obtained in a vacuum of a quadrupole mass spectrometer. These instruments typically operate at vacuums with maximum pressures of no more than 10-4 torr or about 5 × 10-7 bar. Therefore, the vacuum that was used to produce Dr. Humphreys' results was AT LEAST 9 orders of magnitude lower than the natural pressures that his zircons experienced in the subsurface of Fenton Hill (200 to 1,200 bars). Until Dr. Humphreys actually does some high-pressure laboratory experiments, how can he boldly proclaim that a 9-fold pressure increase would never significantly affect the defects in his zircons and the associated defect line supporting his "creation model"? It doesn't take much thought to realize that helium diffusion is going to be much greater from a bare and fractured zircon in a laboratory vacuum than a zircon 750 to 4,310 meters in the subsurface encased in other minerals and possibly bathed in extraneous helium over ten's of thousands of years or longer. Since this is his project, Dr. Humphreys has the burden of proof to demonstrate that such enormous differences in pressure would have no significant effect on his YEC claims and agenda.
Dr. Humphreys must realize that crystal defects can seal under pressure (McDougall and Harrison, 1999, p. 144). Without performing high-pressure laboratory experiments, how can Dr. Humphreys assure us that the numerous cracks and other defects in his zircons would not have been significantly sealed under the subsurface pressures and temperatures (96-313°C; Humphreys et al., 2004, p. 3) at Fenton Hill? As the defects in Dr. Humphreys' zircons begin to seal under pressure, the intrinsic curve (orange line on the Arrhenius plot in my Figure 7) might only lower slightly. However, the defect curve for the zircons (the green line in my Figure 7) would be expected to significantly lower (perhaps by many orders of magnitude) and could easily merge with the intrinsic curve (orange line). The resulting curve would resemble the linear or nearly linear distributions that are often seen in Reiners et al. (2002), Lippolt and Weigel (1988), and even several of the articles cited in Humphreys (2006). That is, under subsurface pressures and at 96-124°C, it would not be surprising if the helium diffusivity of the zircons was six orders of magnitude lower than Dr. Humphreys' vacuum-generated defect curve and would approach Dr. Humphreys' "uniformitarian" curve (see my Figure 7). Furthermore, when the inflated Q/Q0values in Humphreys et al. (2004) and Gentry et al. (1982a) are corrected with the chemical data in Gentry et al. (1982b) (see my Appendix B) and entered into equation 16 of Humphreys et al. (2003a, p. 11), the predicted diffusion coefficients (D) for the "uniformitarian model" would rise about an order of magnitude so that they would pass right through the extended intrinsic curve at 96-124°C. Unlike Dr. Humphreys' magical accelerated radioactive decay fantasies, here are several plausible circumstances that Dr. Humphreys could test with some high-pressure experiments.
Now, YECs might be tempted to view the average "date" of 60,000 years from the "creation model" to be close enough to support young-Earth creationism and refute "uniformitarianism." However, this value is simply an average of a diverse set of meaningless numbers resulting from Dr. Humphreys' equations and inappropriate data. As shown in Table 3 of my November, 2005 essay, the "dates" from the equations in Humphreys et al. (2003a) range anywhere from a few hundred to millions of "years." Even if the equations in Humphreys et al. (2003a) were correct (and they're not), the "dates" from these equations are unrealistically too low because they're based on conditions in a laboratory vacuum of 5 × 10-7 bar or less. These vacuum results give no comfort to anyone that wants to know how these zircons and their helium would have actually behaved in the subsurface of Fenton Hill.
"The upshot is that here Henke is playing the ancient merchant's trick of "bait and switch". Having lured the customer in with an implied promise about one item (helium, zircon, dry), he then tries to sell the customer an item (argon, mica, wet) which will cost him more and benefit him less. I hope you won't buy Henke's merchandise!"
So, why is it improper for me to cite papers dealing with noble gas (helium and argon) diffusion in micas (like phlogopite and glauconite) when Humphreys et al. (2003a) misuses questionable helium diffusion data from biotites to exclude Sample #6 and prop up his "creation model"? (Biotite is a mica, which is a solid solution ["mixture"] of annite and phlogopite.) Also, how am I guilty of "baiting and switching" when the evidence in Laney et al., (1981), Laughlin and Eddy (1977, p. 28), and Sasada (1989) overwhelmingly shows that the Fenton Hill cores had a WET past? Why does Dr. Humphreys continue to embrace Lyell uniformitarian fantasies and proclaim that because the zircons in the Fenton Hill cores were dry when they were collected in the 1970s, they must always have been dry? Why doesn't Dr. Humphreys deal with the consequences of the URANIUM-bearing fluids that once existed in the Fenton Hill cores (West and Laughlin, 1976, p. 618)? Of course, where there's uranium, there's extraneous helium that could contaminant his zircons. Dr. Humphreys needs to accept the fact that the currently dry and impermeable Fenton Hill rocks were once cooler, more permeable, wetter, and contained at least some uranium and extraneous helium (Laney et al., 1981; Laughlin and Eddy, 1977, Sasada, 1989, West and Laughlin, 1976). This is why I have repeatedly requested (including in my original essay) that Dr. Humphreys measure his zircons for 3He and the associated quartz grains for extraneous 4He.
"Numerous researchers have shown that the diffusion of helium or argon in silicate minerals may vary by many orders of magnitude at a given temperature depending on whether the studies were conducted in a vacuum or under pressure. For example, argon diffusion in phlogopite mica may be at least 3 to 6 orders of magnitude higher in a vacuum than under pressurized conditions (McDougall and Harrison, 1999, p. 154.)"
"Argon diffusion in glauconite at 1,000 to 10,000 psi of water vapor is up to three orders of magnitude slower than under a vacuum (Dalrymple and Lanphere, 1969, p. 155)."
Unlike Dr. Humphreys with his mystery math involving questionable results from Gentry et al. (1982a), I have been very open and detailed about the contents, relevance and limitations of the literature that I cite (for examples of the limitations, see my discussions in Appendices A and B).
Dr. Humphreys needs to explain why he continues to ignore the contents of Dunai and Roselieb (1996) and the consequences this article raises for his agenda. I have repeatedly cited this article in both my original March, 2005 essay and my November, 2005 update. Dunai and Roselieb (1996) deals with the SLOW diffusion of helium through garnet, a HARD silicate like zircon. Dunai and Roselieb (1996, p. 412-413) feared that garnets would be too unstable under a vacuum for their experiments. As an alternative, they exposed their garnets to helium under high pressures (250 bars), subsequently measured the amount of the helium incorporated into the garnets, and then calculated the diffusion of helium in the minerals. Garnets are silicate minerals that retain helium very well over time, even at high temperatures. Dunai and Roselieb (1996) concluded that even at high temperatures (700°C), helium would take TENS to HUNDREDS OF MILLIONS OF YEARS TO PARTIALLY DIFFUSE out of garnets. They also discuss the possibility of excess helium in garnets, which Dr. Humphreys should think about with his zircons. Because garnets, like zircons, are hard silicates, the proclamations in Humphreys (2006) on mineral hardness are hardly relevant. The question is, once the defects in his zircons begin to close under pressure would the diffusion of helium in Dr. Humphreys' zircons behave more like these garnets? Again, Dr. Humphreys needs to be responsible and perform these experiments.
(Because the diffusivities of Dr. Humphreys' zircons were measured in a vacuum (P~0), the above equation reduces to equation #2 in Humphreys et al. (2003a, p. 5): D = D0 e [-(E/RT)]).
Pressure-induced strain on minerals and metamict areas in zircons can change their activation energies. Notice that because pressure (P) and activation energy (E) are in the exponent of the above equation, even relatively small changes in these variables could lead to huge changes in diffusion coefficients (D). This is why enormous changes in diffusivity were seen when Humphreys et al. (2003a, Fig. 5, p. 6) fudged the units of measure on the y-axis of the Magomedov (1970) graph from natural logs to base 10 logs. The activation energy nearly tripled to ~40 kcal from Magomedov's listed value of 15 kcal, but the effects on the diffusion coefficients were even more profound and changed by five orders of magnitude. So, even relatively small or moderate changes in activation energy could lead to orders of magnitude changes in diffusion. Furthermore, when Humphreys (2006) cited Carroll (1991) in his attempts to belittle the importance of pressure, Dr. Humphreys failed to mention that Carroll (1991, p. 161) admitted that his pressure range was NOT sufficiently great to determine how pressure might affect the activation energy of his glasses. Rather than hoping and guessing that any pressure-induced changes in the activation energies of his metamict zircons are inconsequential, Dr. Humphreys actually needs to perform the pressure experiments to verify his hopes and defend his "creation model."
Humphreys (2006) unjustifiably believes that the lack of high-pressure noble gas diffusion studies in the literature somehow indicates that pressure is an unimportant variable in helium diffusion. However, the literature suggests alternative explanations on why pressure studies are relatively rare. Pressure experiments can be technically difficult to perform and single runs can take long periods of time to complete. That is, high pressures may slow down diffusion so significantly that it may take weeks or months just to perform one measurement. For example, when Humphreys (2006) refers to the high pressure results in Table 2 of p. 160 of Carroll (1991), he never mentions that some of the runs took almost 65 days to perform. Furthermore, some of the runs performed by Dunai and Roselieb (1996) lasted for 500 hours or nearly three weeks. Dunai and Roselieb (1996, p. 413) also noted that their platinum sample capsules were unable to withstand pressures above 250 bars. Certainly, long-term high-pressure diffusion experiments are difficult to perform, time-consuming and expensive, but how else can the subsurface conditions at Fenton Hill be realistically modeled? Dr. Humphreys must either find some way of properly performing these difficult and expensive experiments or abandon (at least for now) any claims that he has adequately modeled the diffusion of helium under natural conditions in the subsurface of Fenton Hill.
Because Dr. Humphreys collected his zircons from gneisses and not granodiorites (my Figure 1), he needs to realize that thermodynamic and other laboratory studies indicate that gneisses and their metamorphic zircons form under much greater metamorphic temperatures and pressures than could ever have existed at depths of 750 to 4,310 meters (Hyndman, 1985; Winkler, 1979). The gneisses at Fenton Hill were obviously uplifted from much greater depths. By definition, gneisses have gneissic banding, which requires minimum pressures of about 4,000 to 6,000 bars and temperatures of about 600-750°C to form. So, Dr. Humphreys' gneisses and their zircons were once at depths of at least 15-22 kilometers (Winkler, 1979, p. 5), perhaps for much of their history. To be entirely realistic, Dr. Humphreys' diffusion studies not only need to model helium diffusion at depths of 750 meters to 4.3 kilometers, but also depths of greater than 15 kilometers.
Of course, technical difficulties, high costs, and limitations are no indication that pressure is unimportant. As discussed in the above equation, McDougall and Harrison (1999, p. 144) demonstrate that pressure can have profound effects on diffusion. So, until Dr. Humphreys tries to perform some high-pressure experiments, he simply has no evidence to proclaim that helium diffusion under realistic subsurface pressures would support his "creation model."
As I've mentioned many times before, Dr. Humphreys fails to realize that the Fenton Hill zircons could have been bathed in extraneous helium for long periods of time up to a few thousand years ago just as the rocks in the neighboring Valles Caldera currently are. Indeed, the extraneous helium concentrations at about ~1000 meters depth in the Valles Caldera (Smith and Kennedy, 1985, p. 897; Truesdell and Janik, 1986, their Table 8, p. 1831) still exceed the helium concentrations in samples 4, 5, and 6 of Dr. Humphrey's documents. Somehow, Dr. Humphreys believes that when helium rose out of the deep mantle in the recent past and entered the nearby Valles Caldera, it was incapable of traveling a few extra kilometers through abundant fractures that existed at that time to contaminate his samples (also see descriptions of fluid movements through the Fenton Hill core in Sasada, 1989). As long as extraneous helium is present in rocks, the diffusion of radiogenic helium from the zircons may be suppressed. Zircons could even be contaminated with extraneous helium. As I've stated many times before, the extraneous helium could have largely dispersed from the Fenton Hill biotites thousands of years ago during the warming period described in Sasada (1989) and the remaining helium in the biotites could have mostly escaped when ICR personnel improperly ground them. However, extraneous helium could still be present in the relatively impermeable zircons. YECs repeatedly complain about extraneous argon supposedly undermining K-Ar radiometric dating, but Dr. Humphreys won't even consider the possibility that extraneous helium could easily invalidate his "creation model."
As I've stated before, the readership of Talkorigins is probably greater than most peer-reviewed science journals and YEC magazines, including CRSQ . Contrary to the claims in Humphreys (2006), the science essays at Talkorigins are extensively read, reviewed and cited, and are not in a "dark corner" of the Internet."
As part of the review process at Talkorigins, essays are submitted to scientists and the general public through the Talkorigins newsgroup. The non-anonymous reviewers of my March, 2005 essay are listed in the acknowledgements. Also, while I frequently link to his essays, Humphreys (2006) doesn't even have the courage and courtesy to directly link to my November, 2005 essay in his text. Through an intermediary, I had requested that Dr. Humphreys link to my original March, 2005 essay in his responses. He did so (once) in a footnote in Humphreys (2005). However, Humphreys (2006) only hid one unlinked URL of my November, 2005 essay in his references. Dr. Humphreys should explain why he doesn't want the readers of "Trueorigins" to have easy access to my works. Why should I have to request that a copy of my essays receive a convenient clickable link before Dr. Humphreys and "Trueorigins" provide them? Why are Dr. Humphreys and "Trueorigins" afraid of what people might read at Talkorigins?
Dr. Humphreys has wasted a lot of time and money to create his mess and he has yet to present any conclusive evidence to support his "creation model." Humphreys (2006) has challenged me to drop my current research projects and perform high-pressure studies on the Fenton Hill zircons, studies that he should be doing. Dr. Humphreys doesn't seem to realize that he, and not me, has the responsibility to perform ALL of the essential studies (including realistic high-pressure diffusion experiments) before he can promote his "creation model" and claim that he has overthrown the validity of radiometric dating. Furthermore, as I've repeatedly stated in my previous Talkorigins essays, all of his mistakes, invalid assumptions, and mystery math must be explained and corrected before any of his claims can be taken seriously by scientists (Appendix D). Dr. Humphreys has no moral or scientific authority to challenge anyone to perform or publish experiments on this topic until he cleans up his own sloppy data and actually publishes his work in an AUTHENTIC peer-reviewed science journal (such as Earth and Planetary Science Letters or Geochimica et Cosmochimica Acta ).
It's time for Dr. Humphreys' to remove his claims from the dark corner of young-Earth creationism and into the light of real science, where his work can be critically examined without any protection from dogmatic YEC publishers that suppress criticism and hide or omit the references of critics (e.g., Humphreys et al., 2004). Rather than me seeking any "glory" by doing his work for him, it's more important that Dr. Humphreys overcome his denials, and soberly and responsibly deal with the numerous bad assumptions and errors in his work, which are well documented in my previous essays and summarized in my Appendix D. He can start by finally studying Dunai and Roselieb (1996) and maybe he'll get some ideas on how to measure helium diffusion in zircons at high pressure.
Carroll, M. R, 1991, "Diffusion of Ar in Rhyolite, Orthoclase, and Albite Composition Glasses," Earth and Planetary Science Letters , v. 103, p. 156-168.
Dalrymple, G. B. and Lanphere, M. A. 1969. Potassium-argon dating . W. H. Freeman and Company, San Francisco, p. 155, Figure 9-7.
Dunai, T.J. and K. Roselieb, 1996, "Sorption and Diffusion of Helium in Garnet: Implications for Volatile Tracing and Dating," Earth Planet. Sci. Letter , v. 139, p. 411-421.
Farley, K.A., 2002, "(U-Th)/He Dating: Techniques, Calibrations, and Applications," Rev. Min. Geochem. , v. 47, p. 819-844.
Hudson, J. B. and R. Hoffman, 1961, "The Effect of Hydrostatic Pressure on Self-diffusion in Lead," Transactions of the Metallurgical Society of AIME v. 221, August, p. 761-768.
Hyndman, D.W., 1985, Petrology of Igneous and Metamorphic Rocks , McGraw-Hill, New York.
Laney, R., A.W. Laughlin, and M.J. Aldrich, Jr., 1981, Geology and Geochemistry of Samples from Los Alamos National Laboratory HDR Well EE-2, Fenton Hill, New Mexico , LA-8923-MS, National Technical Information Service, Los Alamos National Laboratory, NM.
Laughlin, A.W. and A. Eddy, 1977, Petrolography and Geochemistry of Precambrian Rocks from GT-2 and EE-1 , Los Alamos Scientific Laboratory, Los Alamos, NM, Report LA-6930-MS.
Lippolt, H.J. and E. Weigel, 1988, "4He Diffusion in 40Ar-retentive Minerals," Geochim. et Cosmo. Acta , v. 52, p. 1449-1458.
Magomedov, Sh. A., 1970, "Migration of Radiogenic Products in Zircon," Geokhimiya , v. 2, p. 263-267 (in Russian). English abstract: Geochemistry Internationa l, v. 7, n. 1, p. 203.
McDougall, I. and T. M. Harrison, 1999, Geochronology and Thermochronology by the 40Ar/39Ar Method , Oxford University Press, New York.
Reiners, P.W., K.A. Farley, and H.J. Hickes, 2002, "He Diffusion and (U-Th)/He Thermochronometry of Zircon: Initial Results from Fish Canyon Tuff and Gold Butte," Tectonophysics , v. 349, p. 297-308.
Sasada, M., 1989, "Fluid Inclusion Evidence for Recent Temperature Increases at Fenton Hill Hot Dry Rock Test Site West of the Valles Caldera, New Mexico, U.S.A., J. Volc. and Geotherm. Res. , v. 36, p. 257-266.
Smith, S. P. and B. M. Kennedy, 1985, "Noble Gas Evidence for Two Fluids in the Baca (Valles Caldera) Geothermal Reservoir," Geochimica et Cosmochimica Acta , v. 49, p. 893-902.
Truesdell, A.H. and C.J. Janik, 1986, "Reservoir Processes and Fluid Origins in the Baca Geothermal System, Valles Caldera, New Mexico," J. Geophys. Research , v. 91, n. B2, p. 1817-1833.
West, F.G. and A.W. Laughlin, 1976, "Spectral Gamma Logging in Crystalline Basement Rocks," Geology , v. 4, p. 617-618.
Winkler, H.G.F., 1979, Petrogenesis of Metamorphic Rocks , 5th ed., Springer-Verlag, New York.
Woodmorappe, J. (pseudonym), 1999, The Mythology of Modern Dating Methods , Institute for Creation Research, El Cajon, CA.

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