That interrupt zircon dating of granites above told

To browse Academia. Skip to main content. Log In Sign Up. Zlatka H Cherneva. Bonchev Str. Geological setting determination in the Madan unit regards to the post- kinematic Smilyan granite body specified at The host Madan composed of several orthogneisses dominated tec- unit orthogneiss is of unknown age.

Loechelt a is a detailed rebuttal of Humphreys b and Loechelt b is a less technical summary of his response to Humphreys b. Most recently, Humphreys is a brief letter, where Dr. Humphreys largely recycles the materials in Humphreys b and prematurely declares "victory" without appropriately answering the numerous questions from his critics e.

Figure A. The old Earth multi-domain model from Loechelt c better explains helium diffusion in the Fenton Hill zircons than Dr. The sample numbers are from Gentry et al. Both Dr. Loechelt and I my Appendix A demonstrate that Dr. Humphreys' Q 0 value is too small. As shown in the calculations in my Appendix B of this essay, data from Gentry et al. Zartman analyzed a zircon taken a few meters from sample 3 and probably from the same granodiorite.

This graph was modified from Loechelt c with permission. Figure B. Another hypothesis to explain the helium diffusion data. Subsurface pressures on Dr. Humphreys' and R. Gentry's zircons in the Fenton Hill cores would have been about to 1, bars. If the defect curve in Dr. Humphreys' diffusion studies resulted from voids, fractures and other openings in the zircons, then some of these openings could have been at least partially closed under subsurface pressures. If the openings were substantially closed, the defect curve of Dr.

Humphreys' zircons, which is used to support his young-Earth creation model, would have been lower, aligned more with the intrinsic curve, and perhaps even approached the diffusion results for Dr. Humphreys' strawperson uniformitarian model. The intrinsic curve would be less affected by pressure. Humphreys argues that zircon is too "hard" to have its helium diffusion affected by subsurface pressures.

Humphreys has the responsibility to evaluate any pressure effects on his "dating" scheme before he can proclaim that the Earth is only 6, years old, "accelerated" radioactive decay is factual and that all radiometric dating methods must be discarded.

In my original essayI extensively criticized and documented some of the numerous problems in Dr. Humphreys' work. Rather than dealing with most of his mistakes, it's obvious from Humphreys a and Humphreys that Dr.

Humphreys did not even read and comprehend the vast majority of my criticisms. Humphreys also fails to properly deal with many problems and questions raised by other critics, especially Loechelt c; a.

This essay contains additional evidence and discussions that demonstrate that Dr. Humphreys' work is fatally flawed and never achieves its YEC objectives. Throughout Humphreys a and as recently as Humphreys bDr. Humphreys stresses that his YEC conclusions must be correct because Figure 2 in Humphreys a shows a supposedly strong correlation between his creation model and helium diffusion measurements from Humphreys et al. Humphreys is so mesmerized by his Figure 2 in Humphreys a that he is in denial and will not deal with the serious errors and numerous questions about this figure and his work.

Although Humphreys b accuses his critics including me of supposedly ignoring his diagram, I have long-argued that Dr. Humphreys' diagram has little scientific merit for example, see Figure B and also discussions in Loechelt, c. Any effort to nullify the entire field of geochronology and promote radical changes in our fundamental understanding of nuclear physics would require far more than a single pretty diagram produced from incomplete data, invalid assumptions and numerous faulty interpretations.

Materials engineer Dr. Gary Loechelt in Loechelt c; a also argues that since the beginning of the project, Dr. Humphreys and his colleagues have "tuned" their creation model and its assumptions so that the "consistency" between the creation model and the helium diffusion data is not the decisive result that Humphreys a and Humphreys b want us to believe.

The "dating" equations in Humphreys et al. The vast majority of Humphreys et al. Using the best available chemical data on the Fenton Hill zircons from Gentry et al. There are also serious ethical questions about how Dr. Humphreys handled data from Magomedov and other documents. Contrary to Humphreys ahis mistakes are not petty or peripheral, but completely discredit the reliability of his work.

To correct his mistakes, Dr. Humphreys needs to perform spot analyses for 3 He, 4 He, lead, thorium and uranium on numerous zircons from all of his and R.

Finally, Loechelt a; b; c; a; b shows that multi-domain helium diffusion models, which are far more realistic than the "creationist" and "uniformitarian" models presented by Humphreys et al. As indicated in the Acknowledgments, my essay has been peer-reviewed. Rather than recognizing my peer-reviewers, many of which are scientists, Humphreys a repeatedly challenges me to publish my criticisms of his work in a peer-reviewed scientific journal.

However, it's obvious from Dr. Humphreys' publication record on this topic e. So, before Dr. Humphreys screams about the importance of peer-review, he needs to follow his own advice. He needs to openly publish his work and conclusions as a full article in a legitimate peer-reviewed science journal such as Geochimica et Cosmochimica Acta or American Mineralogist.

Suitably peer-reviewed documents don't include a brief abstract in EOS Humphreys et al. If Dr. Humphreys is really sincere about his devotion to peer-review, let him wean himself off the reliance on miracles for his "accelerated" radioactive decay claims, honestly recognize and correct his numerous mistakes, thoroughly answer the numerous questions from his critics, and submit what's left as a detailed article in a real science journal, where he doesn't have friends that will rubber stamp his work.

Humphreys in Humphreys a and Humphreys thinks that he can just read through the abstract of my original essay or other brief snippets of my work, throw out some insults, try to trivialize his serious mistakes, make bold assertions without any calculations to support them, make a couple of minor corrections here and there, misrepresent critical details in the literature, invoke several irrelevant analogies e.

Now, some individuals might accept this type of arm waving, the invoking of "God did it! Science doesn't work this way and Dr. Humphreys should know better. Humphreys has had more than five years to make a thorough and air-tight case for his claims and produce the detail calculations that he promised in Humphreys a.

As explained in this and my earlier essays, he has wasted a lot of time and money, made a lot of empty claims and promises, and has utterly failed to support his YEC agenda. As further seen in Humphreys b and HumphreysDr. Humphreys continues to ignore the numerous questions and problems with his work.

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 through a series of questions in Appendix C of this essay.

For decades, young-Earth creationists YECs have desperately sought "scientific evidence" to attack radiometric dating and protect their religious views of Earth history.

Although YECs claim to believe that the Bible is the "powerful word of God"they fully realize that just quoting their scriptures is not going to convince geochronologists and other scientists to abandon their research and stream to church altars in repentance.

Simply put, their activities included combing the scientific literature and designing laboratory "experiments" that would somehow verify what they have already concluded, namely that a "literal" interpretation of Genesis is "The Truth" and anything that conflicts with their biblical interpretations is "wrong. Humphreys et al. By inaccurately modeling the helium diffusion rates in the zircons, making numerous invalid assumptions and assuming some unfounded miraculous increases in radioactive decay rates, Humphreys et al.

Loechelt c; a argues that this is no coincidence. Sincea number of PhD physicists and other scientists including at least one young-Earth and several old-Earth creationists have criticized the validity of Humphreys et al. Humphreys' responses to his critics such as Humphreys, a; Humphreys, ; Humphreys, a; Humphreys, b; Humphreys, have been superficial and have totally lacked suitable mathematical and technical details to defend his procedures and YEC conclusions.

Most recently, Humphreys continues to dodge the critical questions that I list in my Appendix C and that other scientists have raised. In his effort to dismiss the extensive criticism of his work from a number of very qualified physics, materials engineering, and geology PhD's, Humphreys b even suggests that his opponents are disorganized and disagreeing with each other:. Each one was unsatisfied enough with the previous criticisms most are familiar enough with the others to borrow their arguments occasionally to take the time to attack the helium data on their own.

Even if Dr. Humphreys' critics disagree, does that necessarily make Dr. Humphreys right? For example, if Dr. Humphreys is automatically right because his critics can't agree? Nevertheless, a review of the available documents from Dr. Humphreys' critics shows a lot of agreement among us.

For example, Whitefiel Loechelt c and I all agree that Dr. Many of us have also protested against Dr. Humphreys' mysterious changes in the Q values from Gentry et al. Had Dr. Humphreys been more open and honest with his math, adequately answered our questions about his work back inand not been so flippant and evasive with the numerous problems with his work, the list of his critics might have been much shorter.

Humphreys is also simply failing to realize that his critics have very diverse areas of expertise in physics, materials engineering and geology and that each one had no difficulty discovering new errors and questionable claims in his work. Humphreys' work is finally undergoing a thorough scientific peer-review that it never received from the editors of the Creation Research Society CRS Humphreys et al. Unfortunately for him, Dr.

Humphreys' critics have shown overwhelming evidence that his study is flawed and useless, and perhaps even contrived to unfairly promote his creation model Loechelt c; a. The vast majority of the errors and unsound assumptions in the Humphreys et al. Some of the major flaws in the Humphreys et al. In particular, Loechelt c corrects many of the equations and parameters in Dr. Humphreys' documents. He further demonstrates that Dr.

Humphreys' data actually support an age of about 1. Humphreys' claims for a "young" 6, years old Earth and his need for "accelerated" radioactive decay. Radon gas escapes uranium bearing minerals, such as zircon, which are embedded in biotite crystals, and migrates to accumulation sites where it decays into polonium, thereby forming a radiohalo.

This theory requires that the heaviest of all noble gases, radon, have the ability to leave its host mineral and travel scores of microns between biotite plates, all within the time constraint determined by the 3. On the other hand, the helium diffusion theory requires that this same biotite trap helium, the lightest of all noble gases, and hold it for thousands of years.

Clearly, the RATE researchers were focused on two isolated phenomena helium diffusion and radiohalos rather than solving a more general problem, like noble gas migration in biotite. Ironically, the helium diffusion study and the polonium radiohalo study are published as consecutive chapters in the same [ RATE] book The vast majority of Dr. For example, Dr. Humphreys should stop picking and choosing from the obviously questionable data in Gentry et al.

He must further realize that the uranium and thorium data in Gentry et al. Rather than ignoring the problems or relying on invalid assumptions about the concentrations of 3 He, 4 He, uranium and thorium in his zircons, Dr. Humphreys actually needs to perform some detailed analyses similar to those in Gentry et al.

Through his small and invalid study, Dr. Humphreys and his allies have made the rash claim that he has overthrown the physics of radioactive decay and radiometric dating.

Well, before Dr. Humphreys can make such a radical claim, he needs evidence. Extraordinary claims demand extensive and high quality data, which Dr. Humphreys doesn't have. If the collection site of a specimen is unknown or if it has been improperly stored for several decades, any resulting data are often useless.

Unfortunately for them, Dr. Throughout their paper, Humphreys et al. More recently, Humphreys et al. Granodiorites are igneous rocks that crystallize from melts magmas deep in the subsurface.

As their name implies, they have intermediate chemical compositions between granites and diorites, which means that granodiorites tend to have more silica than diorites and more magnesium and iron than granites Hyndman,p.

Information in Laughlin et al. Gneisses are former igneous or sedimentary rocks that have been metamorphosed under relatively high temperature and pressure conditions highly altere but without melting Hyndman,p. Even after being presented with evidence from the literature, Humphreys a still refused to admit that he and his colleagues misidentified gneisses as "granodiorites.

Gentry readily admitted in Gentry et al. When Humphreys et al. For that reason it is important to get helium diffusion data on zircon and biotite from the same rock unit the Jemez Granodiorite [ sic ] which was the source of Gentry's samples. Figure 1. The zircons and biotites utilized in Humphreys et al. Of course, the sizes of zircons and biotites can be highly variable depending on the host igneous or metamorphic rock.

Because Humphreys et al. Chemical data in Gentry et al. Humphreys cannot accurately represent the zircons from various depths in the cores with just one Q 0 value see discussions below.

Rather than relying on information in Laughlin et al. John Baumgardner. The following statements by Dr. Baumgardner are quoted in Humphreys a :. In making the selections I made of what samples to use, I purposely avoided these occasional veins.

In fact I tried to select sections of the core well removed from such veins. So at least from my vantage point, the samples of core we used for the helium diffusion measurements were indeed coarse-grained granodiorite, not gneiss. Baumgardner's statement that a "coarse-grained granodiorite" forms "the vast majority of the core" blatantly contradicts statements in Laughlinp. The dominance of gneisses in the Precambrian rocks of the Fenton Hill cores is also obvious from my Figure 1.

Because Dr. Baumgardner's conclusions are inconsistent with the results of professional geologists that have examined and analyzed the cores in great detail, I emailed him with a list of questions about the samples that he had collected for Humphreys et al.

In his kind reply, Dr. Baumgardner described the core as consisting of dark gneissic "veins" surrounded by an "unaltered granodiorite" consisting of "large typically, mm " pinkish grains. Although I requested any mineralogical such as petrographic or X-ray diffraction analyses or chemical data that is, major oxides, minor and trace element analyses that Dr.

Baumgardner might have to support his claims, he provided none. By definition Hyndman,p. Baumgardner claims, where are the light-colored bands of the gneiss? By the definition of a gneiss, how can the Fenton Hill samples have dark gneissic bands and no light-colored gneissic bands associated with them?

Baumgardner seems to have misidentified the light-colored gneissic bands as "unaltered granodiorite. Without detailed chemical and microscopic studies, feldspars and quartz in a light-colored gneiss can readily appear "igneous" and "unaltered" to the naked eye.

In a later email to me, Dr. Baumgardner generously sent photographs of a couple of Fenton Hill cores and described the meter core as a "granite" on the basis of its "abundant" pink orthoclase potassium feldspar grains. He further argued that the meter core was a "granodiorite" because of its lack of pink orthoclase. However, identifying a mineral on the basis of color is unreliable.

Orthoclase can come in many colors besides pink. Other minerals besides orthoclase are also pink. Furthermore, pink feldspars can be abundant in some gneisses and entirely absent in others. Even if the samples were igneous, Dr. Baumgardner's naked-eye observations would not have been adequate enough to distinguish a granodiorite from a granite, monzonite, or any other intermediate or felsic intrusive igneous rock.

Again, Humphreys et al. Finally, according to an April, report by Dr. Baumgardner now admits that Dr. Humphreys' zircons came from gneisses. Feeley writes:. I could see this from the back row, as could the undergraduate geology students in attendance.

At this point he called me 'dumb' and asked if I had the guts to tell Baumgardner who selected the core that the sample was a metamorphic rock and not an igneous rock.

As we walked over to speak with Baumgardner, a young woman who identified herself as a Christian, scolded Humphreys for being mean and not behaving in a Christian-like manner by calling me evil and dumb. To get back to the point, Baumgardner conceded that the core sample was indeed a gneiss and not a granodiorite. To his credit, Humphreys did begrudgingly apologize. In Humphreys aHumphreys b and HumphreysDr. Humphreys continues to inaccurately refer to the relevant metamorphic sections of the Fenton Hill cores as "granitic rock.

In an effort to cloud the issue on the petrology of the host rocks of Dr. Gentry's zircons, the author s at CreationWiki states:. Due to inadequate referencing of this citation, the CreationWiki author s may be referring to a Los Alamos report by Purtymun et al. The information in Purtymun et al.

This report has been replaced by more thorough studies by Laughlin et al. While drill cuttings from intrusive igneous rocks and gneisses are often difficult to distinguish, the well cores used Laughlin et al. Laney et al. Gentry's sample 1 and Dr. Humphreys' zircons. However, Laney et al. Humphreys' zircons came from intrusive igneous rocks. The diagram in Laney et al. Gentry's sample 1 zircons originated. Next, the CreationWiki author s cites some webpage definitions and attempts to claim that a "granodiorite" has a composition that is close enough to be called a "granite.

Nevertheless, careful geologists don't accept the sloppy use of terms to identify igneous rocks. So, there are definite chemical and mineralogical differences between granites and granodiorites that can and must be distinguished by geologists.

In the end, the author s of CreationWiki is being sloppy with rock terms and is trying to create a controversy where one has not existed since the work of Laughlin et al. Misidentifying a gneiss a metamorphic rock as an intrusive igneous rock is no more acceptable than calling frogs "reptiles," and referring to a granodiorite as a granite is like calling a gorilla, a "chimpanzee.

I predicted in my original essay that if Dr. Humphreys ever began to suspect that he and his colleagues sampled gneisses and not a granodiorite, he would try to trivialize his mistakes and argue that misidentifying a gneiss would not significantly affect their zircon diffusion studies or "dating" results.

This is exactly what Humphreys a attempts to do. Humphreys a tries to argue that any misidentification of the rock types in the Fenton Hill cores would not be a serious mistake:.

The uranium, helium, and lead levels in our samples are perfectly consistent with the corresponding levels Gentry reported for his. The effect of variation from sample to sample is probably smaller than the 2-sigma error bars around our prediction.

So here Henke is making a distinction without a difference. Secondly, Dr. Humphreys makes several bold assertions in the above paragraph that are flatly refuted by the chemical data in the very reference that he cites i. Gentry et al. In the case of zircon 1A in Table B1 of my Appendix B, the uranium concentrations vary by more than an order of magnitude within the zircon! Humphreys did not fully realize that his and R. Gentry's teams had sampled zircons from a diverse group of igneous and metamorphic rocks my Figure 1 and Table 1, belowDr.

YECs might argue that because Precambrian granodiorites and gneisses were all magically zapped into existence during the six hour days of the "Creation Week" e. While most YECs invoke miracles to explain away most Precambrian intrusive rocks e. Humphreys has the impossible task of explaining why the numerous metamorphic and igneous rocks in the Fenton Hill cores my Figure 1 have complex structures and textures that indicate a long history Laney et al.

Like an old scratched phonograph record or a dented old car scroll down to "Creationist Car Deal" by Dave Thomasthe properties of a metamorphosed rock often indicate an extensive and complex history involving erosion of precursor igneous, sedimentary and metamorphic rocks; sediment deposition; deep burial of sediments; multiple cooling and heating events; various complex metamorphic reactions; faulting and uplifting.

Humphreys collected his zircons from gneisses and not granodiorites my Figure 1he needs to realize that thermodynamic and other laboratory studies indicate that gneisses and their metamorphic zircons form under much greater metamorphic pressures than could ever have existed at depths of only to 4, meters Hyndman, ; Winkler, The gneisses at Fenton Hill were obviously uplifted from much greater depths.

So, Dr. Humphreys' gneisses and their zircons were once at depths of at least kilometers Winkler,p. Loechelt c in his Appendix A also provides a detailed geologic history of the Fenton Hill cores, which is hardly consistent with a six hour "Creation Week" or even a mere 6, years of history.

Considering that the metamorphic rocks of the Fenton Hill cores probably spent a lot of their history at depths greater than 15 kilometers, Dr. Humphreys is sadly mistaken when he believes that his modeling of helium diffusion in some zircons from current depths of meters to 4.

Humphreys a admits that he "invented" the term "Jemez granodiorite" to describe all of the diverse Precambrian rocks in the Fenton Hill cores. However, the U. Geological Survey's USGS Geologic Names Committee and the North American Stratigraphic Code maintained by The North American Commission on Stratigraphic Nomenclature long ago established rules that professional geologists and other scientists must follow if they want to introduce a name for a rock unit into the literature.

Humphreys and his colleagues violated these rules when they lumped together all of the diverse Precambrian metamorphic and igneous rocks of the Fenton Hill cores and misnamed them the "Jemez granodiorite" Figure 1. Humphreys has not only produced an inaccurate name to describe this diverse group of rocks that could eventually spread clutter and confusion in the literature, he has also shown his inability to properly identify rocks.

Humphreys has further demonstrated that he is incapable of following established scientific rules. Humphreys a and Humphreys et al. Nevertheless, the USGS database and the literature databases Georef and Web of Science contain no references to the existence of the "Beartooth" or "Bear tooth" gneiss or amphibolite accessed June 7, Considering their inabilities to distinguish metamorphic from intrusive igneous rocks when they named the "Jemez granodiorite," who knows if this Beartooth rock is even a gneiss or an amphibolite.

Allowing personnel from the Institute for Creation Research ICR laboratory to grind the biotite specimens could have resulted in substantial helium loss and significant errors in Appendix B of Humphreys et al. Some researchers cut rather than crush micas for argon diffusion studies Dalrymple and Lanphere,p.

According to Humphreys et al. The results in Appendix B of Humphreys et al. As shown by candid statements from ICR's Dr. Steve Austin, the ICR laboratory has a history of not being able to consistently provide adequate mineral and volcanic glass separations also see: "Young-Earth Creationist 'Dating' of a Mt.

As I stated in my original essaywhich Humphreys a ignores, adequately pure biotite separations may not be possible for the Fenton Hill samples. Certainly, Humphreys a is correct when he states that different samples provide different degrees of difficulty in mineral separation. That is, another laboratory also may not have been able to adequately separate the biotites from the Fenton Hill samples.

However, considering the poor record of the ICR laboratory, Dr. Humphreys should have at least tried. Humphreys a again tries to belittle his failures by claiming that the biotite separations are irrelevant. However, if these separations were not important, why did he bother having them done and the questionable helium analyses published? It's also obvious that without these biotite analyses, Dr.

Humphreys' case is weakened. For example, sample 6 doesn't fit into their modeling scheme see discussions below. So, Humphreys et al.

Also, biotite and its helium diffusion properties have critical roles in some of the models described in Humphreys et al. Humphreys' invalid Lyell uniformitarian claim that current measurements of the diffusion of helium in his Fenton Hill biotites somehow rules out the possibility of extraneous helium contamination see below. Instead of adequately responding to the questionable Fenton Hill results from the ICR laboratory, Humphreys a challenged me to do a better job.

But, why should I do his work for him? I simply have no interest in processing samples for Dr. Humphreys so that he can manipulate them to promote his YEC agenda. Q refers to the measured quantity of helium presumably only radiogenic 4 He in a mineral. Helium will only begin to accumulate in a zircon if the mineral is below its helium closure temperature, which is about o C Reiners et al. Even if the "dating" equations16, etc. Otherwise, it's garbage data in, garbage "dates" out.

apologise, too would

As discussed in this and the following sections, the data in Humphreys et al. Most of the results in Humphreys et al. Humphreys' claims about his results being "peer-reviewed. While Humphreys simply listed the helium measurements from Gentry et al. Gentry concluded that the helium measurements in Gentry et al. Their undocumented "corrections" to the measurements in Gentry et al. Samples are from Gentry et al. Revised helium Q values are from Humphreys et al. Depths are from Humphreys et al.

The other lithologies are from Laughlin et al. Humphreys b, p. New or Revised He measurements in Humphreys et al. As others e. Humphreys has yet to reveal adequate details on how these "typographic errors" in Gentry et al.

An unknown writer s at CreationWiki makes the following interesting statement about the discovery of the "typographic errors" in Gentry et al. He noticed an order of magnitude discrepancy in the absolute helium amounts.

When he contacted Gentry, Gentry agreed that they probably were typographical errors. It is not known whether this statement is based on a rumor or first-hand knowledge from Dr. If this account is true, R. Gentry agreed that his paper "probably" contained typographical errors after Dr.

Humphreys obtain his results and noticed a discrepancy between his results and the data in Gentry et al. Humphreys a also admitted that:.

High-precision SHRIMP U-Pb zircon dating of the Suzuoqi diorites and granites are reported. The analysis indicate that the Baiyinbaolidao Na-rich granitoids were formed at 8Ma - 8Ma. U-Pb zircon dating of granites and orthogneisses from the Madan unit in the Arda river valley, Central Rhodopes, Bulgaria U-Pb oe?eiiiai aaoe?aia ia a?aieoe e i?oiaiaene io Iaaaineaoa aaeieoa ii aieeiaoa ia ?. A?aa, Oaio?aeie ?iaiie, Aueaa?ey. On their published U-Pb dating diagram, however, the authors project a line representing the Pb isotope composition of the cores of the very tiny clusters from the billion years age (when the zircon grain supposedly crystallized) to where the line "happens" to intersect the U-Pb isotopes growth curve at the billion years age-the.

Humphreys and R. Gentry did not have R. Gentry's original calculations or laboratory notes, how do they know after more than 20 years that typographic errors had been made in Gentry et al. Was R. Gentry simply admitting to the possibility of "typographic errors" to help his friend, Dr. Humphreys, and the RATE project? How is this mathematically possible?

Correcting errors in previous manuscripts is certainly honorable. However, authors should not agree to any "corrections" unless they can first review their original laboratory notes and confirm that copying, analytical or other errors were indeed made. In other words, scientists should not admit to making mistakes before seeing the evidence. As discussed below, there are numerous incidences where Dr. Humphreys has unjustly manipulated e. Therefore, documenting the validity of the changes to the helium values from Gentry et al.

Humphreys needs to fully explain this issue and dispel any possible thoughts that "typographic errors" were invoked so that the data in Gentry et al. Humphreys and his YEC agenda. Until Dr. Gentry give a full and detailed account of what actually happened, we simply have no reason to trust any of the data in Gentry et al. Nevertheless, as discussed below, even if the revisions of the Q values in Gentry et al. Finally, the lack of documentation from Dr. Humphreys to justify changes in the published data of Gentry et al.

The Different Levels of Granite

Any editor or peer-reviewer of a legitimate scientific journal would demand a thorough and complete explanation of why these changes are justified before any revisions would be allowed to appear in their journals. Competent editors and reviewers would also insist that if the original laboratory notes had been lost that the results be discarded and the analyses redone.

Once a mineral cools below its helium closure temperature and remains below that temperature, Q 0 is the maximum amount of radiogenic helium 4 He that is expected to accumulate in the mineral from the radioactive decay of its uranium and thorium. A certain percentage of alpha particles 4 He nuclei will escape from the host mineral during radioactive decay and this loss is considered when calculating the Q 0 values.

My Appendix B, Loechelt cand their references discuss how alpha particle loss may be estimated. Using a series of questionable and vague assumptions, Gentry et al. Using the available information from Gentry et al. Instead, I found that the assumptions in Gentry et al. Loechelt c, p. Meanwhile, Humphreys a still won't adequately explain how he and supposedly Gentry et al.

Gentry, Gentry et al. Rather than admitting that the assumptions in Gentry et al. He is in the right ball park, but he is probably using too small a value for the percentage of alpha particles helium nuclei emitted by the nuclear decay escaping the zircons. The percentage came from Gentry's paper, but Gentry may have misstated what he meant by the number. Certainly, there are plenty of questionable assumptions and unreliable numbers in Gentry et al.

So, why is Dr. When will the list of errors in Gentry et al.

U-Pb zircon dating of granites and orthogneisses from the Madan unit in the Arda river valley, Central Rhodopes, Bulgaria U-Pb . In this study, zircon U-Pb ages and Hf-O isotopes, as well as whole-rock Nd isotopes are presented for the oldest known igneous rocks in the SQT. Precise SIMS zircon U-Pb dating of these rocks reveals that these early Paleozoic granites were crystallized at ca. ? Wei Dan, Wei Dan, Qiang Wang, Qiang Wang, Xiu-Zheng Zhang, Gong-Jian Tang, Gong-Jian Tang. On the other hand, the younger granites are peraluminous and exhibit the characteristics of A-type granites; these are post-collisional granites. The U-Pb SHRIMP dating of zircons revealed the ages of magmatic crystallization as well as the presence of slightly older, presumably inherited zircon grains.

Clearly, Dr. Humphreys invokes "typographical errors" and "misstatements" in Gentry et al. As further discussed in Appendix A, the dodging and delays in Humphreys a and his willingness to selectively alter the values and assumptions in Gentry et al.

Humphreys' "date" for the Fenton Hill zircons by "only" two orders of magnitude or from "6," to ", years. Gentry's errors associated with Q 0 are just one of many problems associated with Dr. Humphreys' work and claims, the CreationWiki author s attempts to dismiss this two orders of magnitude "dating" problem by invoking an inexplicable "heating event.

CreationWiki doesn't say. Again, Dr. Humphreys and his allies fail to realize that the errors associated with their Q 0 value and the numerous other questions and errors associated with Dr. Humphreys' equations and parameters only accumulate and illustrate how frail and unreliable his "dating" methods really are.

Certainly, Appendix A demonstrates that there are serious errors in the calculations of Gentry et al. However, even if Gentry et al.

Indeed, Gentry et al. However, given the limited options with the data from Gentry et al. While the calculations in Gentry et al. Hence, when the standard correction for alpha-ejection is made for samples which have also experienced loss due to diffusion, significant errors can result. Gentry's samples. Table 2 lists Dr. Loechelt's values and compares them with the values in Gentry et al. Like Dr. Humphreys, Loechelt c, p.

However, unlike Dr. Humphreys, Dr. Loechelt's results strongly favor his "old-Earth" model Figure A. Nevertheless, as stated above, the differences in the lithologies of the Fenton Hill core and the diverse chemical data of the zircons in Gentry et al. Isaac b also questions the validity of the Q 0 value used by R.

Gentry and Dr. Humphreys from a different perspective:. If so, how did Gentry make that calculation? What were his assumptions?

That amount of helium was never concentrated in the zircon at the same time. Subsequent discussion by the RATE team shows that the justification for speculating that accelerated nuclear decay occurred is based largely on a young earth as determined by helium diffusion in zircons. This is circular reasoning at best. Rather than properly explaining the mysterious changes in the helium concentrations Q taken from Gentry et al.

Gentry], I'm inclined to think that even if he [R. So, why does Dr. The answer is clear. Just as he avoided explaining and justifying the mysterious changes in the Q values of Gentry et al. Instead of promptly showing his calculations to quickly settle these critical issues, Humphreys a simply delayed the inevitable by making a vague promise to provide the necessary details in another CRSQ article sometime in the near future:. Of course, after all these years, we're still waiting for Dr.

Humphreys' promised paper with its critical calculations and justifications. Because Humphreys a had no problem performing the necessary calculations and correcting his mistake in Appendix C of Humphreys et al.

Mar 09, Rapakivi granites and several small leucogabbroic and gabbroic bodies are located in the Rangnim Massif, North Korea. The largest batholith in the Myohyang Mountains covers an area of km 2 and was intruded into Precambrian metamorphosed rocks. It has a SHRIMP U-Pb zircon weighted mean Pb/ Pb age of 7 Ma. The country rocks of rapakivi granites are Neoarchaean Cited by: Zircon has a high refraction index and, when the crystals are large enough, is often used as a gemstone. In geology, zircon is used for radiometric dating of zircon-bearing rocks (using isotopes of U which is often present as an impurity element, as is Th, radiogenic Pb, Hf, Y, P, and others). Compare 'UMSiO:CaNaZr'. THE COMPOSITION OF ZIRCON IN THE PERALUMINOUS HERCYNIAN GRANITES OF THE SPANISH CENTRAL SYSTEM BATHOLITH We have investigated the zircon from granites of the Spanish Central System (SCS) batholith. This batholith is composed of attempts at Rb-Sr dating have failed, suggesting a heterogeneous isotopic character.

Why the delay? The evidence indicates that after Dr. Humphreys discovered the "typographic errors" that allowed him to "correct" the Q values in Gentry et al. Until these accurate values become available, the best available chemical data for these calculations are in Gentry et al. The data in Gentry et al. The uranium and thorium concentrations also show that Humphreys et al. Specifically, Gentry et al. In contrast, the chemical data from Gentry et al. Humphreys' "dating equations", they often raise Humphreys et al.

Meanwhile, Humphreys a and his subsequent documents never comment on the results in my Appendix B and how they have even greater negative impacts on his YEC model than the values in my Appendix A.

After correcting his mistake, Humphreys a chides me for not being skeptical enough of his work. In this case, Dr. Humphreys is right. There is no reason to trust Dr. Humphreys to properly handle any data. In their modeling efforts, Humphreys et al. Of course, zircons have tetragonal anisotropic rather than isotropic crystalline structures, which would cause at least some anisotropy in the flow of helium through the minerals. Nevertheless, Loechelt c, p.

It has been demonstrated through direct computation, however, that a simpler spherical geometry is a reasonably good approximation provided the effective radius is chosen such that the surface-to-volume ratio of the sphere is the same as the geometry Loechelt's emphasis]. In contrast, Reiners et al. The width of a tetragonal prism may be readily determined by sieving, whereas the lengths cannot this is why you can push a long strand of uncooked spaghetti through a window screen, but not a piece of typing paper.

Because zircon crystals tend to be elongated, Dr. Humphreys' a values would be significantly longer than values obtained using the more widely accepted definition in Reiners et al.

Rather than always carefully measuring critical factors such as the lengths and widths of his zircons, Humphreys a admits that the sizes of the zircons in his meter sample were never determined. Instead, he simply assumed that a was 30 microns. Heimlich performed numerous measurements on zircons from various sections of the Fenton Hill cores. Based on the widths in Heimlichthe average half-width a as defined by Reiners et al.

Estimating a at 30 microns, 20 microns or a similar value may seem trivial. However, similar studies show that poorly defined a values can introduce huge errors in the argon diffusion coefficients of feldspars, which are silicate minerals McDougall and Harrison,p. Specifically, Mussett showed that improper estimates of a can cause the argon diffusion coefficients D values to vary by over seven orders of magnitude at a given temperature also see McDougall and Harrison,p.

So, even if isotropic diffusion is a reasonable assumption for Dr. Humphreys' zircons, inaccurate a values for the Fenton Hill zircons could introduce unacceptable errors into "dating" equations and 16 of Humphreys et al. Like many other issues dealing with Dr.

Humphreys' helium in zircon studies, the author s at CreationWiki also fails to recognize the inadequacy of Dr. Humphreys' measurements of a and the seriousness of poorly defined and inaccurate values of aQ 0and other parameters to Dr. Humphreys' YEC equations and agenda. Some of Dr. Humphreys' "dating equations" require accurate values of b that are not currently available. Biotite is a mica, which is a well-layered silicate mineral. Because of the well-developed and prominent cleavage planes between the biotite layers, the layers can be readily peeled off with finger nails.

The cleavage planes also make biotite very anisotropic. Helium would tend to migrate through the planes rather than perpendicular or oblique to them. Obviously, Humphreys et al. The models in Humphreys et al. The variable b must be known in order to obtain "helium diffusion dates" from equations and 17 in Humphreys et al. In my original essayI criticized Humphreys et al. Because descriptions in Laughlin et al. Rather than providing suitable measurements and standard deviations for bHumphreys a again throws out the same old lame excuses.

He tries to belittle his mistakes by claiming that accurate b values really aren't important because the biotites supposedly only have minor effects on his results.

However, Dr. Humphreys fails to remember that his single b value played a key role in his efforts to remove sample 6 from his models and obtain his desired "helium diffusion date" of 6, years see discussions below.

Even if accurate b values were not very important to his "dating" efforts, Dr. Humphreys' omission of valid averages and standard deviations for any of his data is not a trivial issue. His lack of suitable averages and standard deviations whether for his a or b values exposes serious shortcomings in his laboratory procedures.

Finally, Humphreys a replies to my criticisms of his b measurements with the following nonsensical statement:. I need to remind Dr. Humphreys that his papers only contain one b value, which is supposedly an average as listed at Humphreys et al. Contrary to the claims in Humphreys athe necessary raw data to calculate a standard deviation for b are not present in any of his documents. So, how can anyone obtain an unbiased n-1 standard deviation from only one number?!

Calculating the standard deviation would lead to division by zero! This is yet another example of Dr. Humphreys flippantly trying to dismiss criticism without really thinking about the ridiculous implications of his rash replies. Without his log base manipulation of Magomedov's graph, Dr. Humphreys' methodology provides ridiculous "creation" dates of only a few decades for Magomedov's zircons.

Only a brief abstract of Magomedov is readily available in English:. Humphreys, however, has an English translation of the entire Russian article Humphreys et al.

Based on helium diffusion results of zircons from the Fish Canyon Tuff Reiners et al. Based on this faulty assumption, Humphreys et al. As further discussed below, Dr. Humphreys' unjustified manipulation of the data in Magomedov exposes his inability to properly handle the literature, even with an English translation.

Figure 2. Arrhenius plot of helium diffusion in zircons from the Soviet Union gray triangles; Magomedov,Nevada black circles; Reiners et al. Although Dr. Humphreys has an English translation of Magomedovit's obvious that he did not carefully study the article and its equations. The equations in Magomedov clearly refute Dr. Humphreys' log 10 D interpretation. The standard Arrhenius equation in Magomedovhis Equation 4states:. Magomedov even admits that he used his e-based Equation 4 to construct his Figure 3, which is the graph that Humphreys et al.

Magomedov states:. English Translation: "Using Equation 4it is possible to determine the values of E and D 0 by constructing a graph of the relationship ln D vs. In Figure 3, ln D is plotted as a function of reciprocal temperature for lead and helium. The slope of the curves calculates the corresponding values of E.

Magomedov's Equation 4 also appears as Equation 2 in Humphreys et al. Humphreys should know that this equation is e-based and not base To use log 10 D in Equation 4 of Magomedov,a conversion factor of 2. From his Equation 4, Magomedov derives the following natural log ln equation his Equation 5 :. Natural logs ln are the taken on both sides of the equation. The use of log base 10, as Dr. Humphreys desires, would require inserting the 2. Magomedov only shows a graph of his helium diffusion data and does not list any numerical results in a table.

However, he does list his lead diffusion results in his Table 1, which conclusively demonstrate that Magomedov was using natural logs in his equations and graphs, and not log 10 D as Dr. Humphreys desires. Also, see my Table 3 and the English abstract above.

If "ln" means log 10 in Magomedovas Dr. Also, there is also no reason to believe that Magomedov would inconsistently use "ln" to represent natural log in Equation 5, but have "ln" represent log 10 on the y-axis of his Figure 3. Table 3: Confirmation that lead diffusion results in Table 1 of Magomedov are based on natural logs and not log base 10 as desired by Humphreys et al.

The use of ln as a natural log rather than log base 10 is also verified by further comparing the lead data at and o C in Magomedov's Table 1 with the ln graph in his Figure 2b. Natural log values from the results in Table 1 correspond well with the points in the graph of Figure 2b in Magomedovbut log base 10 values are far too small.

As an additional confirmation that Magomedov was using natural logs, when the temperature and diffusion coefficients from Magomedov's Table 2 are entered into Magomedov's Equation 5, the resulting activation energy E is The use of log base 10 diffusion values with the data in Table 2 of Magomedov would yield an activation energy of only Clearly, the data within Magomedov overwhelmingly indicates that he was using natural logs.

Humphreys has absolutely no justification for arguing for a log base 10 interpretation of the Magomedov data and fudging Magomedov's helium diffusion data to support his YEC agenda. As discussed below, the ramifications of the natural log format in Magomedov undermine Dr.

Humphreys' YEC agenda. The high helium diffusion coefficients in the Magomedov are not surprising considering that Magomedov's zircons were very metamict damaged by a lot of radioactive decay. There is also an 11 order of magnitude difference wow! Considering how the physical and chemical properties of zircons may significantly vary from one specimen to another, Humphreys et al. While Humphreys et al. Humphreys' manipulation. In the process of fudging the units on the y-axis of Figure 3 in Magomedov from natural log to log base 10, Humphreys et al.

Humphreys, the author s at CreationWiki completely ignores the equations, figures and tables of supporting data in Magomedov that conclusively indicate the use of natural logs. The author s attempts to defend Dr. Humphreys' log base 10 interpretation of the Magomedov data by showing that an "activation energy" E of Although the CreationWiki author s claimed to have drawn a "best fit" line through the Magomedov data, it is difficult to believe that Magomedov would derive his activation energy for helium by passing a single line through only two points selected from his obviously diverse intrinsic and extrinsic curves.

Not even Dr. Humphreys supports the CreationWiki approach for determining the activation energy of this sample see Figure 6 in Humphreys,p. Figure 3. In an unsuccessful attempt to defend Dr. Humphreys a accuses me of lying when I stated in my original essay that Humphreys et al.

But how else can we describe the actions of Humphreys et al. Without any legitimate justification and in contradiction to the very equations, figures and tables of data in MagomedovHumphreys et al. Humphreys has no excuse for either ignoring or incompetently misinterpreting the equations and data in Magomedov Humphreys' willingness to alter results from the literature to suit his religious agenda is not a "ridiculous quibble" as he claims in Humphreys abut a serious act of misconduct that illustrates how fast and loose he is with data.

What happens if everybody else's "view" of helium diffusion doesn't apply to these highly metamict Soviet zircons? Even Humphreys et al. So, when individuals like Dr. Humphreys ignore their own previous warnings, unquestionably manipulate a data set from the literature to comply with the results that they want and then boast that their results are "consistent" with the manipulation Humphreys et al.

Humphreys' misuse of the Magomedov data shows that he is willing to do just about anything if an opportunity arises to manipulate a data set to promote his anti-science agenda. One can only wonder if Dr. Humphreys used the same type of manipulation to convince R. Gentry to admit to "typographic errors" in his Q values so that R. Gentry's values could also be "corrected" to comply with Dr.

Humphreys' results. Humphreys' "Dating Equations". The high helium diffusion rates in the Soviet zircons based on natural logs have dire consequences for Dr.

Humphreys' "dating" equations. Instead of discussing the Magomedov data and adequately explaining his manipulation, Humphreys a accuses me of just wanting to reject the Magomedov data because I find them "inconvenient.

Without fudging the Soviet data, Dr. Humphreys is put into an extremely inconvenient position of trying to explain why these Soviet results are several orders of magnitude higher than his measurements my Figure 2 and why his "dating" approach indicates that these Soviet zircons were "created" in the 20th century.

New insights into the concept of ilmenite as an indicator for diamond exploration, based on kimberlit petrographic analysis. U-Pb age and geochemistry of zircon from mantle xenoliths of the Katoka and Kat kimberlitic pipes Republic of Angola.

In Doklady Earth Sciences Vol. Nikitina, L. Villanova, M. Castillo, M. Campeny, A. Melgarejo : Niobium and rare earth minerals from the Virulundo carbonatite, Namibe, Angola. Mineralogical Magazine 76, Grew, E.

Antarctic Journal of the U. In addition, I collected samples of intrusive rocks, including lamproite, late Archean pegmatites containing orthopyroxene, sillimanite, wagnerite, Mg,Fe 2PO4 F,OHand a distinctive suite of beryllium minerals, and of Early Paleozoic pegmatites containing beryl, tourmaline, dumortierite, kyanite and muscovite.

Sheraton, J. Highly potassic mafic dykes from Antarctica. Journal of the Geological Society of Australia, 27 Carson, M. Hand and P. Dirks Stable coexistence of grandidierite and kornerupine during medium pressure granulite facies metamorphism. Mineralogical Magazine Minor, D. Geochimica et Cosmochimica Acta, 61 12 Meteoritics 24 4 Dec Luttinen, A. Geological Magazine, 5 Harris, C. South African Journal of Geology, 3 American Mineralogist 76, Polarforschung, 80 3 Geological Magazine,4, Giorgetti, G.

Terra Antartica, 1 1 Semenova, A. Cenozoic peralkaline magmatism at the western margin of the Ross Sea, Antarctica. Memorie della Societa Geologica Italiana, 46, Hawkes, Donald D. Smellie, J. Stratigraphy, geochemistry and evolution. Cambridge, British Antarctic Survey, 85 pages. British Antarctic Survey Scientific Reports, Goldring, D. British Antarctic Survey. Bukovanska, M. Meteoritics 28 3 : July The Canadian Mineralogist, 52 2 Colombo, F.

Author information

Haluska El Torio en la naturaleza. Buenos Aires. Victorio Angelelli, M. Gordillo y H. Gay Angelelli, V. Milka K. Asociacion Mineralogica Argentina. Zappettini, E. Zafiros aluvionales de la Puna, Jujuy.

Chernicoff, C. Hf isotope study of Palaeozoic metaigneous rocks of La pampa province and implications for the occurrence of juvenile early Neoproterozoic Tonian magmatism in south-central Argentina. Journal of South American Earth Sciences, 32 4 AndGeo vol. Galliski, M. Geochemistry and structural state of columbite-group minerals in granitic pegmatites of the Pampean Ranges, Argentina.

The Canadian Mineralogist, 44 3 Asociacion Mineralogica Argentina ; Galliski, M. Distrito minero El Quemado, Deptos. La Poma y Cachi, provincia de Salta. Argentina, 38, The Canadian Mineralogist, 50 6 Galliski et al. Canadian Mineralogist Vol. Sillitoe, R.

Economic Geology, 3 Rudashevsky, N. Canadian Mineralogist Hugo A. In Alkaline Rocks and Carbonatites of the World pp. Springer Netherlands. Atlantic Ocean. Sharkov, E. Uitgeverij Artis, Brussel in Dutch. New South Wales Arrawatta Co. Brown R. E Brown and W. Bland Co. Wormald, R. Peralkaline granites near Temora, southern New South Wales: tectonic and petrological implications. Journal of the Geological Society of Australia, 35 2 Buller Co.

Brown, H. Henley and W. Clarke Co. Brownlow J. Gilligan, L. Clive Co. Henley, H. Cumberland Co. Branagan, D. Dampier Co.

Smith, I. Fractionation in a zoned monzonite pluton: Mount Dromedary, southeastern Australia. Geological Magazine, 3 Dowling Co. Drake Co. Stroud, December, Durham Co.

apologise, but

Byrnes, J. Fitzroy Co. Gloucester Co. Gough Co. Brown, R.

Zircon Chronology: Dating the Oldest Material on Earth main content. Part of the Earth Inside and Out Curriculum Collection. What are the oldest rocks on Earth, and how did they form? The material that holds the greatest insight into these fundamental questions, because it can contain a record of some of the earliest history of the Earth, is a. Halunwusu Composite Granites,locates in the northern margin of Belt,between the North Qaidam block and the Central Qilian block,with two phases of magmatic activities. The granites mainly consisits of the Early adamellite to granodiorite and the late granite(Fig1). 2 Result Analysis Zircon U-Pb dating LAICPMS zircon U-Pb analysis of the Author: Gang Tao, Lidong Zhu, Wenguang Yang, Zhiwu Li, Long Xie. granites from the Western Carpathians, Slovakia, combines precise single zircon TIMS U-Pb dating (CLC-method: Poller, ), and in situ Cameca and SHRIMP ion microprobe U-Pb dating with REE and trace element analyses by ion microprobe, and panchromatic and monochromatic CL by scanning electron microscope. By combin-.

Barnes R. Schaltegger, U. Chemical Geology, 3 Chemical Geology - Hardinge Co. Hume Co. Killara Co. Armistead, S. Macquarie Co. England, B. Mineralogical Record, 22 2BSE image of monazite, zircon, rutile, and quartz "from beach sands near Port Macquarie" on p.

Murchison Co. Buchester K. Ure Smith, Australia, p. Northumberland Co. Parry Co. Hollis, J.

The zircon U-Pb dating and standard zircons (including, istics of zircon from A-type granites and comparison to zircon of S-type gran-ites. Lithos , e Young-Earth creationists consider the helium diffusion studies of D. Russell Humphreys and others to be one of their greatest achievements in arguing for a 6, year old Earth. This critique shows that these studies are extensively flawed and include: serious miscalculations in their data, sampling the wrong rock type from the Fenton Hill site, failing to eliminate possible contamination from. Zircon fission-track dating of granites from the Vepor-Gemer Belt (Western Carpathians): constraints for the Early Alpine exhumation history Dusan PlasIenka1, Igor BrOska2 *, Dana kIssOva2, Istvan Dunkl3 1Department of Geology and Palaeontology, Comenius University, Mlynska dolina G, 15 Bratislava, Slovakia.

Richmond Co. Roxburgh Co. Sandon Co. Barron, L. Vernon Co. Wellington Co. Sutherland, F. Mineralogical Magazine, 67 4 Westmoreland Co. Yancowinna Co. Blampain, P. The Western Mineralisation-Rasp Mine. Broken Hill Exploration Initiative, 8. Parr, J. Canadian Mineralogist, 30, Teale, G.

Geoscience Australia Record, 21, PhD thesis, University of Western Sydney. Yanda Co. Heydon, D. Ryan, G. Archibald, D. Skirrow, R. Crohn, P. Strangways Range. England The Australian Mineralogist Aprilpp. The age of the mud tank carbonatite, strangways range, northern territory. Currie, K. The Mud Tank carbonatite complex, central Australia-an example of metasomatism at mid-crustal levels.

Contributions to Mineralogy and Petrology, 3 Nelson, D. Geochemical and isotopic systematics in carbonatites and implications for the evolution of ocean-island sources.

Geochimica et Cosmochimica Acta, 52 1 Wilson, A. Contrast in the isotopic composition of oxygen and carbon between the Mud Tank Carbonatite and the marbles in the granulite terrane of the Strangways Range, central Australia.

Zircon dating of granites

Journal of the Geological Society of Australia, 26 Mackie, A. Sharrad, K. Drake-Brockman, J. McColl, D. Sankey, Major J. Stephenson, P. Northern Queensland. Veevers, J. The geology of the Emerald 1: Sheet area, Queensland. Report of Bureau of Mineral Resources.

what words..., brilliant

Geology and Geophysics, Raffan, N. Carr, P. Australian Journal of Mineralogy, 14 2 Sielecki, R. Mineralogical Record, Vol. Minerals, 3 3 Mineralium Deposita 44 Edwards, A. Scapolitisation in the Cloncurry district of northwestern Queensland. Journal of the Geological Society of Australia, Stolz, A. Fluid activity in the lower crust and upper mantle: mineralogical evidence bearing on the origin of amphibole and scapolite in ultramafic and mafic granulite xenoliths. Mineralogical Magazine, 51 5 Taylor, G.

Laycock, J. North Stradbroke Island. Papers, Department of Geology, University of Queensland, 8 2 McDougall, I. Tertiary volcanism in the Cape Hillsborough area, north Queensland. Journal of the Geological Society of Australia, 18 4 Tertiary volcanic-plutonic rocks of the Cape Hillsborough-Mount Jukes area.

Carson, C. Collerson, K. Application of spinifex biogeochemistry to identify mineralisation targets in obscured basement terranes beneath the Simpson Deserts in South Western Queensland - Final Report. Duggan, et al. Phosphate minerals in altered andesite from Mount Perry, Queensland, Australia.

Canadian Mineralogist, 28, Bryan, W. American Journal of Science, 10 Ewart, A. The petrology and petrogenesis of the Tertiary anorogenic mafic lavas of southern and central Queensland, Australia-possible implications for crustal thickening. Contributions to Mineralogy and Petrology, 75 2 Cainozoic volcanic centres in southeastern Queensland: with special reference to the Main Range, Bunya Mountains, and the volcanic centres of the northern Brisbane coastal region.

Department of Geology, University of Queensland, Papers, 11 part 3 Cohen, B. Australian Journal of Earth Sciences, 54 1 Lava Plains, NE Queensland, gem mineral suite.

Clark, J. Lintern, M. Nicolson, B. Domnick, U. Minerals 10, Wulser PA et al. The sandstone-hosted Beverley uranium deposit, Lake Frome Basin, South Australia: mineralogy, geochemistry, and a time-constrained model for its genesis.

Economic Geology, 5 Rowlands, N. Drexel, J. Griessmann, M. Improved map and genetic implications of the Mount Mulga barite-iron-oxide-copper-gold-deposit-preliminary results.

Broken Hill Exploration Initiative, Waterhouse, J. Vella, L. Geophysical characteristics of the Carrapateena iron-oxide copper-gold deposit. Nikolakopoulos, D. Ehrig, K. Economic Geology Special Publication 16, pg. Dalgarno, C. AAPG Bulletin, 49 3 Ferguson, J. Petrogenesis of kimberlitic rocks and associated xenoliths of southeastern Australia, - Boyd, F. Kimberlites, Diatremes, and Diamonds: Their geology, petrology, and geochemistry. Proceedings of the Second International Kimberlite Conference.

Tucker, D. Lamprophyric intrusions of probable carbonatitic affinity from South Australia. Journal of the Geological Society of Australia, 19 3 Stracke, K. Structural setting of kimberlites in south-eastern Australia. Bottrill, R. Geological Survey Tasmania Bulletin 73, pages.

Tasmanian Geological Survey. Anderson, C. Records of the Australian Museum pp Taheri, J. Calver, C. Timing and genesis of the Karoo-Ferrar large igneous province:New high precision U-Pb data for Tasmania confirm short duration of the major magmatic pulse. Chemical Geology. Melluso, L.

The late crystallization stages of low-Ti, low-Fe tholeiitic magmas: insights from evolved Antarctic and Tasmanian rocks. Lithos, Occurrences of gemstone minerals in Tasmania. Mineral Resources Tasmania. Rept, Mineral Resources Tasmania.

Hajitaheri, J. Specimens collected and visually identified by Toby Billing out of buried alluvial deposits. George Baker The heavy minerals of some Victorian granitic rocks.

Proceedings of the Royal Society of Victoria 54 2 : Museum Victoria collection B. McMahon Zircons from Lake Bullenmerri, Victoria. The Australian Mineralogist No.

Eagle, R. Phosphate minerals in granitic pegmatites from the Mount Wills District, north-eastern Victoria. Proceedings of the Royal Society of Victoria, 2 Petrology, petrogenesis and mineralisation of the Silurian pegmatites of the Mount Wills district, northeastern Victoria.

Sc Hons thesis, University of Ballarat unpubl. Australian Journal of Earth Sciences, 61, - Steve Sorrell Collection. Birch, W. Australian J. Cochrane, G. Geological Survey of Victoria Bulletin No. Dunn, E. Bulletins of the Geological Survey of Victoria No. The Woolshed Valley, Beechworth. Department of Mines. Spencer-Jones D. Bulletins of the Geological Survey of Victoria, No. Mock, C. Frost, M. Holmquistite-bearing amphibolite from Greenbushes, western Australia.

Mineralogical Magazine, 51 62 Fetherston, J. Part IV. Referral Document. Support Document. IPL North Proposal, Published in Meteoritics and Planetary Science Supplement, id. Sept Hou, B. Hickman, A. Rasmussen, B. Geology, 32, Geology, 40 1 Downes, P. Australian Journal of Mineralogy 12, Rugless, C.

Australian Journal of Earth Sciences, 43 3 Taylor, W. Orth, K. Morin-Ka, S. Berger, V. Mineralogy and Petrology, Cummins range carbonatite. Melbourne: Australasian Institute of Mining and Metallurgy. Sun, S. Isotopic evolution of the Kimberley block, Western Australia. Festerston, J.

Hollis, S. Precambrian Research, Ikeda, Y. Padbury and Vaca Muerta mesosiderites: Magmatic and residue or cumulate rock types. Erickson, T. Nature Communications 11, Article Douglas, G. Geology, geochemistry and mineralogy of the lignite-hosted Ambassador palaeochannel uranium and multi-element deposit, Gunbarrel Basin, Western Australia. Mineralium Deposita, 46 7 Rep no. Ferguson, K.

Jacobson, M. Seat, Z. Thesis, University of Western Australia. Simpson, Edward S. Hesperian Press, Carlisle, Western Australia, p 8. Fetherston, J, Stocklmayer, S. Cox, M. Geology, September Pearson, J. Hesperian Press, Carlisle, Western Australia, pages. Bridge, P.

Mineralogical Magazine Pegmatites of Western Australia; M. Calderwood, B. Grguric; Hesperian Press Perth The Mineralogical Record, 8 2 Calderwood, M.

Simpson, E. Volume Government Printer, Perth. Hamilton, R. Lithos, 24 4 Grguric, B. Australian Journal of Mineralogy, Vol. July ; Hsu, W. Alvin, M. Mineralogy and Petrology, 80 Nature and genesis of a carbonatite-associated fluorite deposit at Speewah, East Kimberley region, Western Australia.

Gwalani, L. The Yungul carbonatite dykes associated with the epithermal fluorite deposit at Speewah, Kimberley, Australia: carbon and oxygen isotope constraints on their origin. Mineralogy and Petrology, 98 Puttner, M. Pichler, A. Mikl, A. Mineralienwelt 25 4in German.

Walter, F. Carinthia II, Niedermayr, I. Meixner, H. Kolitsch, U. Formal- u. Wien, S. Exkursion E 7. Niedermayr, G. Wien 78, ; Koller, F. Knobloch, G. Wien, Feitzinger, G. Steinwender, C. PUTZ, H. Mineralogisches Archiv Salzburg, 13, Rauchkopf; Riedingscharte. Preite D. Seeman, R. Lower Riffl glacier. Strasser, A. Der Steirische Mineralog 31, Schachinger, T. Der Steirische Mineralog, 27, Weninger, H. Postl, W. Wismut, Bismutit, Beryll und Apatit? Mitteilungen der Abteilung fuer Mineralogie am Landesmuseum Joanneum Jahrgang, p.

Alker, A. Heritsch, H. Auer, C. Der Steirische Mineralog, 34, Taucher, J. Der Steirische Mineralog, 29, Grachev, A. Mali, H. Joannea Mineralogie 2, Landesmuseum Joanneum, 56, Steiermark Purtscheller, F. Leonhard im Pitztal. Wenger, H. Tiroler Landesmuseums Ferdinandeum 59, Schulz, O. Springer, Berlin, Heidelberg. Jahrgang, 2. Heft, Seite -Verlag R. Pirngruber, Linz Wallenta [cited in: Reiter, E.

Kirchner, W. Meditz, H. Arthofer, P. Geonachrichten 20, Brandstetter, G. Mineralien-Welt 10 3 Ahmed, S. Bangladesh Journal of Scientific and Industrial Research, 45 1 : Hatert, F. Dimanche, F. Hautes Fagnes, 19. Billiet, V. Dejonghe, L. Renard, A.

Santa Cruz. Artiaga, D. From cold to hot: post-Hirnantian sedimentary basins in Bolivia-A source rock for hydrocarbon deposits in the Andes? MS Thesis University of Stavanger. Torres, B. Minerals, 9 8 Grundmann, G. Minerals, 7 568; doi Banco Minero de Bolivia, pp. Lindgren, W. Economic Geology, 23, 3, Bosnia and Herzegovina. Mudrinic, C. Arhiv za Rudarstvo i Tehnologiju 7, in Croatian. Lenharo, S. Petrology and textural evolution of granites associated with tin and rare-metals mineralization at the Pitinga mine, Amazonas, Brazil.

Lithos, 66 1 Lemanski, Jr. Brazilian Journal of Geology, 30 4 Bastos Neto, V. Pereira, L. Ronchi, E. Canadian Mineralogist 47, Journal of Geochemical Exploration, 66 1 Franz, G.

Zircon Chronology: Dating the Oldest Material on Earth

The crystals sit in a matrix of polygonal quartz Qtzwith muscovite Mu preferably along quartz grain boundaries, accompanied by hematite Hemrutile Rut and rare phosphate berlinite Ber; black areas in a near berlinite and in b near muscovite are outbreaks in thin section. Notable is a high micro-porosity, especially well visible in a. The zircon crystals also show the craters produced by laser ablation for age determination.

In portuguese with abstract in english. Overstreet, William C. Economic Geology, 2 Thorman, C. Rao, A. In International Geological Congress Vol. Sauer, J.

Gemological Institute of America, pp. Dutra, C. Geochimica Brasiliensis, 9 2. Geological Survey Open-File Report17 p.

Abrahao Moura et al. Queiroz, H. PhD Thesis. Luvizotto, Giorgio Garuti, Ronald J. Minerals 6 3 Minerals 9, Silva, M. Traversa, G. Nascimento, M. Minerals, 9 7 PhD thesis. Baijot, M.

Canadian Mineralogist 52, Chaves, M. Andrade, K. Diamond News, Part 1, Vol. Cassedanne, J. Mineralogical Record, 14 4 : Fernando R. Pires and A. Raphael Cabral The Volta Grande pegmatites, Minas Gerais, Brazil: an example of rare-element granitic pegmatites exceptionally enriched in lithium and rubidium: Discussion.

The Canadian Mineralogist, 36, Lobato, L. Brugger, J. Lee, T. Two new zircon minerals; orvillite and oliveiraite. American Journal of Science, Tschermaks Mineralogische und Petrographische Mitteilungen, 10, Horstpeter H. Chris D. Parkinson et al. Monteiro, L. Grainger, C.

Mineralium Deposita, 39 1 Klein, E. Beurlen, H.

Facebook twitter google_plus reddit linkedin

0 thoughts on “Zircon dating of granites

Leave a Reply