Direct dating of gold by radiogenic helium best dating site in italy
In 2003, many Christian fundamentalists became very excited about YEC statements in Humphreys et al. ( 2003b, 2004) concluded that the zircons are only "6,000 ± 2,000 years old." Not surprisingly, their results conveniently straddle Bishop Ussher's classical 4004 BC "Genesis creation date" for the world. (2003a) and related YEC documents are clearly based on numerous invalid assumptions, flawed arguments, and questionable data, which include: values of uranium- and thorium-rich zircons.
Humphreys' reply is also availiable in a PDF version. For decades, young-Earth creationists (YECs) have desperately sought "scientific evidence" to attack radiometric dating and protect their religious interpretations of Earth history. By "modeling" the helium diffusion rates in the zircons and assuming some unfounded miraculous increases in radioactive decay rates, Humphreys et al.
(2003a,b) clearly sampled a Precambrian gneiss (a highly metamorphosed volcanic, intrusive or sedimentary rock) and not a granodiorite (an intermediate intrusive igneous rock) (Table 1). (2003a,b), including helium concentrations (Q in nano cubic centimeters of helium per microgram of zircon at standard temperature and pressure [STP], ncc STP/μg) from Gentry et al. 1130), revised helium (Q) values in Humphreys et al. Zartman (1979) provides a date of 1500 ± 20 million years old for the biotite granodiorite (Jemez) at a depth of 2,903.8 meters. However, I would argue that my values in Tables 2 and 3 are the best that we can currently obtain. Thus our experiments support Gentry's data." [my emphasis] Because the "540" nmol/g is only a partial helium measurement and not a finalized total value, Humphreys et al. 3) have no justification for even reporting this value as an "approximation" in their Table 1 (that is, ~ 12.1 ncc STP/μg). The fallacy of this comparison becomes very clear when all of the data in Table C1 of Appendix C of Humphreys et al. If the nmol/g concentrations of helium are summed for the 14 steps (5.337083...
Table 1: Information on the Fenton Hill, New Mexico, well core from Gentry et al. Not surprisingly, the zircons from the Precambrian gneiss at 750 meters depth provide a somewhat younger date of 1439.3 ± 1.8 million years old (Appendix A of Humphreys et al., 2003a). 18) also found that the U/Pb dates for the zircons and epidotes from the Jemez granodiorite were discordant. Although my Q/Q zircon results at depths of 39 meters (samples 5 and 6 in Table 1) are similar to those in Humphreys et al. (1982a), my values from 960 meters (sample 1) and samples 2-4 in Table 2 are always significantly lower. Farley performed helium analyses on zircons from a depth of 750 meters in the Fenton Hill GT-2 borehole core. Farley was not informed that he was providing data for a YEC project (Humphreys et al., 2003a, p. 171.5538), the total amount of released helium is 864 nmol/g and not 540 nmol/g.
Updated information on this RATE project is summarized in Humphreys et al.
(2003b) (Adobe Acrobat file), Humphreys (2003), and Humphreys et al. Many YECs sincerely believe that these articles are excellent examples of high quality "research" by YEC "scientists" and a crowning achievement for the RATE committee. (2003a) and related documents primarily deal with the diffusion of helium from uranium- and thorium-bearing zircons (zirconium silicate, Zr Si OHe, which only has one neutron per atom, is "primordial" (Dalrymple, 1984, p. 1129) (Adobe Acrobat file) lists the half-lives (THe to rise from the Earth's interior, mix, accumulate in minerals in the upper crust, and then perhaps eventually escape into the atmosphere (also see Baxter, 2003). (2003a,b; 2004) and Humphreys (2003) discuss the supposed "young Earth" implications of their helium diffusion experiments with zircons. 15) further speculate that their global "burst of accelerated nuclear decay" could have occurred during the "Creation Week," "the Fall of Adam and Eve," and/or "Noah's Flood." However, for some reason, Humphreys et al.
Because of these and other problems, the YEC "dates" and conclusions in Humphreys et al.
(2003a,b; 2004), Humphreys (2003), their key references, claims from Humphrey et al.'s YEC allies, and comments by various skeptics of RATE demonstrate that Humphreys et al.'s "research" is based on unsubstantiated claims, questionable numbers, invalid assumptions, inconsistent equations, and many flawed arguments.
As discussed below, some of their mistakes may be trivial.
Humphreys has replied to some of Meert's criticisms. Unless privacy issues are involved, authors should identify their opponents and the opponents' literature so that readers can readily evaluate both sides of an issue and fairly make up their own minds.
Despite some inaccurate statements by RATE critics, a careful review of Humphreys et al.