Asked (Or Sometimes Asked Questions About Young Earth Creationist Geology)
Created January 12, 2000
Updated Feb 24, 2002
(Special Note: Clickable Links are used to explain some
of the concepts rather than repeat them here)
ANOTHER NOTE: A U-M student has done an excellent job detailing the arguments against thrusting here
Why does this question come up? Creationists have 'discovered' locations where the fossil record is 'out-of-sequence' (i.e. older fossils on top of younger fossils. One of the explanations given by conventional geology is that the older sequence was thrust over the younger sequence of rocks. Creationists have detailed (in many places) that thrust faulting seems, to them anyway, impossible (creationists claims below are from this site). There are several claims (most of them of personal incredulity) that the Lewis thrust fault shows no evidence of deformation. One of the most humorous of these claims is given below:
"At the actual contact line,
very thin layers of shale were always present . . A thin band of soft shale sticks to the
upper block of Altyn limestone. This seems to clearly indicate that, just before the Altyn
limestone was deposited . . a thin wafer-like one-eighth to one-sixteenth inch layer of
shale was deposited . . Careful study of the various locations showed no evidence of any
grinding or sliding action or slicken sides such as one would expect to find on the
hypothesis of a vast overthrust. "
It appears that geologists are baffled by the lack of deformation in the 'shale'. The real answer is that the 'shale' is the evidence for the faulting. van der Pluijm and Vroljik (1998) made the following observations about the Lewis thrust:
"Gouge, a low-temperature type of fine-grained fault rock, is a product of near-surface faulting. Clays are a common component of fault gouge, but their genesis and importance is poorly understood. In part, the very small grain size that is inherent in these rocks hinders detailed study through approaches that have worked so well in medium- to high-grade fault-rocks (i.e., phyllonites and mylonites). Whereas it is generally assumed that gouge is a result of brittle deformation processes, we will focus on the role of clays in extensive mineral reactions and associated microfabric changes. One striking example is a profile of % illite in mixed-layer illite/smectite in shales beneath the Lewis thrust, Canada. "
There is a Cretaceous shale bed beneath the thrust fault (important for another reason as shown below), but this is different from the 'one-eighth to one-sixteenth inch layer' being discussed above. The thin layer is fault gouge---clear evidence for motion. These same authors discuss the implications for faulting and fluid flow along the Lewis thrust system and also examine the microstructural evidence for the motion. Creationists also seem perplexed by the lack of deformation in associated rocks claiming that:
"The Lewis overthrust should have pushed a great mass of broken rock (rubble or breccia) along in front of it and on its sides as it traveled sideways overland. But it did not do this. That, in itself, is a proof that the Lewis overthrust did not move sideways! "
Fantasy is nice, but reality is better. In fact, deformation within and surrounding the Lewis thrust is well-known. Mudge (1977) describes the geology of Glacier National Park. His abstract notes:
"Glacier National Park has a spectacular glaciated, mountainous terrain of Precambrian Belt sedimentary rocks which in early Tertiary time were displaced eastward onto Cretaceous rocks by the Lewis thrust fault. The park has been the setting for at least ten periods of glaciation. This paper summarizes the pre-Quaternary geology in and adjacent to the park. The pre-Quaternary rocks range from Precambrian Belt to Tertiary in age. The Belt Supergroup strata range in age from about 1,325 m.y. to about 900 m.y. They contain the Purcell Lava, which is a basalt flow (1,075 m.y.), as well as gabbroic sills and some dikes of the same age. The Precambrian strata are mostly reddish-brown and greenish-gray argillite and siltite with some quartzite (Greyson, Spokane and Snowslip Formations). The Empire Formation is recognized in the park, and it is a transitional unit as much as 1,170 ft (375 m) thick between the underlying Spokane Formation and the overlying Helena Formation. The Altyn, Helena, and Shepard Formations compose the Belt carbonate units. Parts of Glacier National Park and the adjacent areas are in the northern disturbed belt of Montana. The area east of the mountains contains thrust-faulted and folded Upper Cretaceous strata; it is equivalent to the Foothills structural province in southern Alberta. The area southeast of the park contains thrust-faulted and folded Jurassic and Cretaceous rocks, which locally are transected by northeasterly trending normal faults. These strata plunge northwest beneath the Lewis thrust plate and are not exposed in southern Alberta and British Columbia, except possibly in the Haig Brook and Cate Creek windows in the Lewis plate in British Columbia. The Lewis thrust plate is deformed by numerous folds and small normal and thrust faults. The major structure in the plate is a northwesterly trending, doubly plunging syncline. The largest normal fault is the Blacktail fault, which extends northwestward into British Columbia as the Flathead fault. West of it are other northwetsterly trending normal faults. The measured minimum easterly translation of the Lewis is 15 mi (24 km), but it may have moved at least 40 mi (64.4 km). The park is in a southwesterly trending, structurally low area that is bounded on the north and south by southwest-trending structures. The structural configuration of the basement that influenced the present setting of the park was very likely established by the end of Cretaceous time, and it probably controlled the present structural pattern in the area, a pattern resulting from the Laramide (early Tertiary) orogeny."
What would a creationist claim be if it did not include a misrepresentation of a paper. The website linked above contains the following 'quote':
"If we assume that rocks have no tensile strength . . then when the pore fluid pressure exceeds the least compressive stress, fractures will form normal to that stress direction. These fractures limit pore pressure . . We suggest that pore pressure may never get high enough to allow gravity gliding . .; the rocks might fail in vertical hydrofracture first."*J.H. Willemin, *P.L. Guth, and *K.V. Hodges, "High Fluid Pressure, Isothermal Surfaces for appreciable distances."*Philip B. King, "The Anatomy and Habitat of Low-Angle Thrust Faults," in American Journal of Science, Vol. 258-A, 1960, p. 115. "
Now, first things first, the correct date for this paper would be 1979 as Hodges was but a lad in 1960. Secondly, this was published in abstract form and the full publication came out in 1982 under the title; "Limitations on the role of pore pressure in gravity gliding" (Guth, Hodges and Willemin, 1982). Creationists are arguing that fluid pressure is not a strong candidate for facilitating thrust motion, but what do the authors conclude? The abstract sums it up best:
"We have developed a simple model to evaluate the gravity gliding of nappes in sedimentary terranes. Three factors play a critical role in the model: (1) the ratio of horizontal to vertical stress, (2) the rate of fluid flow to the detachment horizon, and (3) the permeability of lithologies immediately above that horizon. If the ratio of horizontal to vertical stress is less than one, this ratio limits the maximum available pore pressure through hydrofracture. Existing in-situ stress measurements suggest that vertical hydrofracturing rather than gravity gliding might be the result of elevated pore pressures, unless a low-strength cap-rock exists. If the ratio exceeds one, a relatively simple equation relates the 'cap-rock' permeability and fluid flow necessary for gravity gliding. Effective cap-rock permeabilities less than 10-4 to 10-5 md are required for gravity gliding in a sedimentary basin. Based on available in-situ permeability measurements, only shales and evaporites could have sufficiently low permeabilities on a regional scale"
Note that the layer beneath the thrust, is, indeed a Cretaceous shale. The creationist case rests upon misrepresentation and misquotation. The facts demonstrate that thrust-fault motion is not a problem for conventional geology. For a general discussion of structural geology and faulting, I can recommend Earth Structure and website.
1. Guth et al., 1982, Geol. Soc. Am. Bull 93, pp. 606-612.
2. Mudge, M., 1977, Bulletin of Can. Pet. Geo., 25, 736-751.
3. van der Pluijm and Vrolijk, 1998, GSA Abstracts 1988, p. 103.
This is one of the more popular of the creationist claims. The argument can be summarized as follows:
(a) How old is that rock?
(b) It's Triassic because it contains X-fossil
(c) How do you know how old the fossil is?
(d) Because it is in a Triassic rock.
If this were really how fossils/rocks were dated, there would indeed be a proper call for circular reasoning. The problem is that the above scenario is a strawman picture of geochronology. One of the most commonly cited articles used by creationists to 'support' their claim is by J.E. O'Rourke (Am J. Sci, 1976). The lead paragraph (found in creationist writings) says:
"The intelligent layman has long suspected circular reasoning in the use of rocks to date fossils and fossils to date rocks. The geologist has never bothered to think of a good reply, feeling the explanations are not worth the trouble as long as the work brings results. This is supposed to be hard-headed pragmatism."
Of course, the creationists never bother to read the rest of the paper where O' Rourke goes on to explain his first paragraph. You will not see, for example, the following quote also from that paper:
"Evolution is more than a useful biologic concept; it is a natural law controlling the history of all phenomena and can be deduced from such fundamental relationships as the indestructibility of matter, the constant sum of motion, and the conservation of energy"
Finally, one often finds an incomplete quote from the conclusion of the paper. For the record, here is the complete quote:
"The charge of circular reasoning in stratigraphy can be handled in several ways. It can be ignored, as not the proper concern of the public. It can be denied, by calling down the Law of evolution. Fossils date rocks, not vice-versa, and that's that. It can be admitted, as a common practice. The time scales of physics and astronomy are obtained by comparing one process with another. They can also be compared with the geologic processes of sedimentation, organic evolution and radioactivity. Or, it can be avoided, by pragmatic reasoning.
The first step is to explain what is done in the field in simple terms that can be tested directly. The field man records his sense perceptions on isomorphic maps and sections, abstracts the more diagnositc rock features, and arranges them according to their vertical order. He compares this local sequence to the global column obtained from great many man-years of work by his predecessors. As long as this cognitive process is acknowledged as the pragmatic basis of stratigraphy, both local and global sections can be treated as chronologies without reproach."
O'Rourke is examining the practice of assigning ages to geologic strata based on the index fossils contained therein in the absence of geochronologic constraints in that particular section. The point is made that the order of the fossil record is so internally consistent (as documented by previous work) that it is ok to use geochronologic control from other well-dated sections with similar fossils to assign the age. Since 1976, geologists have become skilled at dating sedimentary successions via radiometric dating. The ages assigned to strata are now based on radiometric ages and these ages validate the idea of faunal succession originally conceived by stratigraphers.
One additional point to make about the work of O'Rourke. On page 53, he states:
"The vertical sequence of fossils is thought to represent a process because the enclosing rocks are interpreted as a process. The rocks do date the fossils, but the fossils date the rocks more accurately. Stratigraphy cannot avoid this kind of reasoning, if it insists on using only temporal concepts, because circularity in inherent in the derivation of time scales."
What is he saying? The underlined phrase is very important here. In fact, even young earth creationists agree with the statement, they simply assign the 'process' to a global flood. What O'Rourke is saying is that a sequence of rocks is laid down in a particular order. All rocks are not deposited instantaneously. No special training is needed to understand this point. Therefore, the rocks were emplaced in a temporal sequence. We can argue elsewhere about how long the sequence is (days, minutes, seconds, millions of years), but there is no debate that the rocks themselves (by their very existence) indicate the passage of time. Therefore the rocks DO date fossils insofaras the fossils in the rocks were not all deposited simultaneously. The fact that radiometric dates have now been assigned to many of these sedimentary units means that the fossils can also be assigned an age. Therefore, the fossils can be used to date the rocks and the rocks can be used to date the fossils (in a relative sense). The point is that this is not a circular argument, but one that is based on observation and logic.
Note the description of "unreasonably young." Does this sound like an orthodoxy had already been established "early in the century" about the age of rocks? It would seem that way. It would also seem that this orthodoxy was not going to be changed, despite findings to the contrary. What is one of the main reasons that old-earthers (and Darwinists) denounce and vilify young-earthers? It is that they refuse to change their beliefs despite evidence or findings to the contrary. Yet here we see this refusal to change beliefs being openly practiced and even tacitly defended. (These new-found ages are too young; and so there. We wont even use the dating method.) If fact, write Zeitler, et al., when potassium-argon and other methods of dating were developed in the 1950s U-Th-He dating was relegated to "relative obscurity." That is to say, the method (and the data) that produced the "unreasonably young" ages were tossed out. Does this sound like the type of behavior that creationists are constantly being accused of practicing? Does it sound like "scientific" behavior? Zeitler, et al. (and the other authors we will be examining) go on to acknowledge the recrudescence of U-Th-He dating, and acknowledge that it appears to have its merits. The fact remains that at one time it and its too-young dates were tossed out because the dates did not conform to the reigning orthodoxy.
JM: I believe that these authors should have been more clear. In fact, early U-He ages were denounced because they yielded ages that were too old (i.e. older than Kelvins age determination for the Earth). If you want to read an excellent account of the development of the U-Pb method read The Dating game by Cherry Lewis. Once geochemists and physicists realized the endpoint of the Uranium decay series was not 4He, they began work on the U-Pb and Pb-Pb methods. This subsequent work showed the discrepancy between U-Pb ages and U-He ages which had the tendency to yield younger ages. Thus, the statement by Zeitler et al. (1987) reflects only part of the history of U-He dating and is indeed valid taken in the correct context. Youre skepticism is unwarranted in this case because you neglected the full context. More on that in a moment.
Further on in the Introduction the authors write, "Geologists currently interpret most mineral ages as cooling ages . . .." They do what? They "interpret." This goes back to what I have been saying on CARM for several months. Everyone has access to the same evidence. The difference is in how it is interpreted, and those interpretations are based on something other than there mere facts of science; for instance on philosophy, pre-suppositions, and so forth.
JM: This argument is specious. You are trying to take the cautious and careful approach of science and turn it into a guessing game. Science proceeds cautiously and carefully. The approach has led to considerable success (consider the medium in which we are discussing this issue). What you have yet to show is a similar chain of scientific successes on the part of ye-creationism. It is interesting to note that young earth views were dismissed by the cumulative success of science nearly two centuries ago. Nothing new has come forward to change the weight in favor of a young earth. However, lets get to the meat of this statement. Why are they interpreted as cooling ages? This is because of the observation that igneous rocks cool (no inferences needed!) and that different minerals crystallize at different temperatures (see Bowens Reaction Series. Therefore, it is entirely reasonable to make this interpretation. Can you show why this interpretation is incorrect? Let me give you a case history of cooling ages and how well the interpretation works. For the experimental details of cooling/blocking temperatures in rocks see McDougall and Harrison . The Carion granite intrudes continental crust in Madagascar. A series of age determinations were made on this granite as given below: (ref: Carion manuscript pdf]
U-Pb SHRIMP: 532.1 +/- 5.2 Ma
40Ar/ 39Ar hornblende: 512.7 +/- 1.3 Ma
40Ar/ 39Ar biotite: 478.9 +/- 1.0 Ma
40Ar/ 39Ar K-spar: 466 +/- 5 Ma
40Ar/ 39Ar K-spar: 410 +/- 5 Ma
The last two ages are reported in Meert et al. (in press, Cooling of a late syn-orogenic pluton: evidence from laser K-feldspar modelling of the Carion granite, Madagascar, Gondwana Research). The cooling curve for this pluton can be viewed here. The pluton (some 20 km in diameter) shows clear evidence of slow-cooling as one might expect for a large igneous pluton intruded into warm continental crust. For the mathematics of slow cooling you can go here. The reason that most mineral ages are interpreted as cooling ages is because there is a wealthy body of observational and experimental evidence in support of minerals forming and closing during cooling. However, not all mineral ages are considered cooling ages. Why? If one looks at the equation given in the link above, a small igneous intrusion (or flow) cools very quickly and therefore the mineral ages will be equivalent to the age of the rock itself. In one sense, the ages are still cooling ages, but since the cooling was essentially instantaneous they are equivalent to formation age. Your entire argument seems to be one of philosophical semantics that neglects the careful critical eyes of science. What you have NOT shown is how the ye-creationist world-view is superior (overall) in determining the age of the Earth. Unfortunately, this is not what the RATE Goup is attempting. They are convinced that if they can demonstrate an anomaly or two, they will have dismissed the old earth in favor of a young earth. None, I repeat, none of their proposed experiments can establish this. All they can do is point out that in a natural world, there are bound to be anomalies. Science know this and considers the data in toto and seeks to understand the anomalies. Another critical point is that the RATE group has so far been unwilling to have their arguments heard in mainstream science. One will never overturn a paradigm by an appeal to the masses or by refusing to have data independently evaluated. Creationists obviously use scientific peer-reviewed articles in their work, but fail to have their work examined by the mainstream scientific world. Why?
All of the five papers I read state that the closure temperature for He is approximately 100 degrees C (212 F), although some of the authors go as low as 75 degrees C (167 F). Apparently the closure temperature is the temperature at which the lattice structure of the rock shrinks to the extent that it traps He. In their discussion of He loss, Wolf et al. write, "An additional effect that would cause greater He loss is direct solar heating of the rock surface. The temperature increase associated with such heating is sensitive to specific geometric and radiative properties of the rock. In a study of granitic boulders in the Mojave desert, Roth found that rock surfaces exceeded the air temperature typically by no more that 20 degrees Centigrade. Adopting this figure as a constant offset added to the daytime temperatures yields a reasonable upper limit to the temperature of rock surfaces in Death Valley . Under these conditions, the mean diffusivity is equivalent to a temperature of 48 degrees C <118 F>, and 2 percent loss occurs in just over 100 kyr. In environments where temperatures and insolation are high and erosion is slow, this effect may require consideration."
I construe this as meaning that if the rocks being tested become very hot (from the sun in this case) and if erosion of the rock surfaces occurs slowly, the (U+Th)/He dating method may have to be adjusted accordingly. My point here is that surficial rocks get this hot (118 F), or hotter, thus requiring adjustments in the dates obtained; and of course erosion must be taken into account.
There is also the problem of forest fires. In their final paragraph, Wolf et al. write, "Although He diffuses rapidly from apatite at fairly low temperatures, natural fires and extreme Earth surface temperatures should not significantly affect He ages except under unusual circumstances." What is a significant effect? What are "unusual" circumstances? Wolf et al. do not address this. ("Modeling of the temperature sensitivity of the apatite (U-Th)/He thermochronometer," Wolf, et al., 148:105-114; 1998.)
JM: Yet again, you did not read far enough. Both of those terms are explained in the text. Signficance is defined by 2% loss of helium (page 112). The authors use this figure in an arbitrary way to test how severe natural conditions would have to be in order to generate helium loss. Unusual circumstances are defined in section 3.4. The authors estimate maximum temperatures of surficial effects. Anything outside of that range would be considered unusual. One additional note, granite has a fairly high albedo, gabbros and basalts absorb a lot more. You are correct that Wolf et al. (1998) do not discuss the measure of significance or unusual. This may be due to the fact that they cannot quantify these effects yet. As I noted above, science proceeds cautiously and carefully so the authors have not quantified either and leave it to future projects to make these determinations. Methods are refined and tested. You have discovered possible ways to improve the method and test effects. Good for you, now how about telling us what refinements and tests will result in a young earth?
Returning to Zeitler et al., they make one interesting comment on He loss in their samples. In the final sentence of their introduction they write, "We find that this apatite has retained its radiogenic He-4 over 30 m.y., yet during laboratory heating loses its He-4 systematically by volume diffusion at quite low temperature." How very interesting and what is that "quite low temperature"? The authors do not specify it, at least not in the introduction. Another interesting tidbit is found on p. 2868, col. 1, where they write, "The diffusion systematics of He in apatite under natural hydrous conditions and at low temperatures might be quite different than those measured under vacuum." Apparently, field conditions (actual conditions) may be somewhat different from those found in the laboratory.
Next we have "(Uranium+thorium)/helium dating of apatite: experience with samples from different geochemical environments," by Lippolt, et al., Chem. Geol., 112: 179-191; (1994). In their abstract, these authors write that they compared their apatite He indices with "plausible reference ages". What is a "plausible" age? It almost sounds like there is an orthodoxy that must be adhered to.
JM: This will be an important lesson
for you to read beyond the introduction and the abstract of papers. Indeed, it might even
be useful for you to take a course in isotope geology. Lets begin with your first
incomplete statement. You claim they do not specify what quite low
temperatures are. Indeed, they do tell you what this is. Page 2868 says:
" Our data indicate that temperatures as low as 50 oC could result in 50% loss of 4He in as few as 106 years. "
Now, why did you leave this out? Lets look at your next incomplete statement regarding the experimental conditions. Your quote is correct, but you left out the very preceding sentence that says:
"We emphasize that this value represents the fruit of a reconnaissance study only."
Or that further on they state:
"A useful next step will be to examine U-Th-He ages of apatite in geological context such as boreholes and intrusive contacts to determine the more general applicability of this approach"
Why were these not included? Indeed, Lippolt et al. (1994) follow this suggestion by Zeitler et al, 1987 to a tee!. Their definition of plausible age is given in table 2. You are playing a semantics game. Lippolt et al. could just have easily said earlier determined ages. Your conspiracy inference is unwarranted.
In their introduction, Lippolt et al. write that "absence of extraneous helium" is a prerequisite for a good sample. How is the researcher supposed to distinguish between radiogenic He on the one hand, and "extraneous" He on the other hand? Helium is helium, is it not? I doubt that the radiogenic He comes complete with a marker enabling the worker to distinguish it from extraneous He.
JM: I suggest you read about 4He, 3He and 5He, 6He, 7He, 8He, 9He and how these are determined. One might turn the question around and ask: If you think this is a problem for science, how does the RATE group proposal solve it? One should never argue from personal incredulity!
In their Conclusions (p. 198, col. 1) Lippolt et al. write that five of their six samples "showed enough uranium and thorium contents and presumably negligible amounts of excess He-4 with the exception of one hydrothermal apatite which showed very low radioactivity and rather high amounts of extraneous He-4." "Presumably" negligible amounts of "excess" helium. Thats pretty exacting. And how about that "extraneous" He-4? How do the authors know it is extraneous?
They go on to write that their He-4 indices "are all significantly below isotopic age data derived from associated silicates. However, the He indices are very similar to fission-track ages of the sampling areas which reflect cooling ages of the pertinent rocks below temperatures of approximately 100 C. Thus, our results confirm the interpretation of Zeitler et al. ."
Need I exegete this? The He dates are "significantly" lower that isotopic dates from associated silicates. Note also that the word "interpretation" occurs again. There are other qualifiers on page 189, including the need for "very fast cooling" to make certain types of measurements, and need for samples free of "common" helium, by which the authors doubtless mean extraneous helium.
JM: Once again you criticize the research for being cautious. If this is the best argument you have against science, then your arguments are in trouble. But lets look at your first out-of-full context quote from the conclusions. You question as to how they figure out the problem of excess Helium, but you did not read (or did not include) the explanation. Indeed, on page 184 (column 1) this is explained. The authors state:
"Provided that the uranium and thorium concentrations are >1 or >5 ppm respectiely, it is very unlikely the 4Heinitial would have a measurable effect".
Do you know why that is? Did you also note that the concentrations in the sample that gave weird results? Hint: U was much less than 1 and Thorium was much less than 5. If you did know, why did you leave this out of your review? As for the conclusions, they do indeed support the notion of Zeitler et al. (1987) that Helium is readily diffusible under low-temperature conditions in specific geologic environments and that one should always be aware of the geologic context within the samples. It does not conclude that the method is always wrong nor does it conclude that it is always right. It expresses that the ages be used with caution. The main point of both of these papers is that if U-He is to have any use, it most likely will be in the determination of cooling histories not absolute ages. The authors are indeed testing some of the assumptions in radiometric dating using this method and trying to determine when/how/if it can be used. This is the same procedure used in other isotopic dating. In fact, one needs to confront the very real problem for ye-creationists to develop a specific instance in which all concordant dates can be explained in physical-chemical terms while at the same time describing how these same physical-chemical events provide different ages. Geologists and geochemists have answers to both questions. Ye-creationists resort to conspiracy theories such as yours.
In the Introduction to the next paper, Wolf et al. write, "In most cases the helium ages were younger than expected, . . ." although they go on to explain this away, citing a 1954 book by Hurley. Again, we see an acknowledgement of ages outside of the orthodoxy. ("Helium diffusion and low-temperature thermochronometry of apatite," by Wolf, et al., Geochim et Cosmo, 60: 4231-4240, 1996)
JM: Conspiracy theory again! Please note that you have ignored the fact that early U-He ages were rejected by mainstream science because they were too old! You have also ignored the fact that during this tumultuous debate regarding radiometric dating, Rutherford and others showed why U-He was not trustworthy given the present state of knowledge. Many took Rutherfords explanation to indicate that Kelvin was right and the geochronologists were wrong. Of course, even Kelvins estimate is too old for ye-creationism.
On page 4239, col. 1, Wolf et al. note a closure temperature of 75 C (167 F) and write that this temperature is "so low that it is important to consider how much helium will be lost at ambient temperatures on the Earths surface." They go on to say, "However, at temperatures as low as 45 C <113 F>, measured helium ages will be low by almost 40 percent over this same period <100 million years>." They then acknowledge the need for corrections for "diffusive loss at ambient temperatures." In their Conclusions (p. 4239) the word "interpretation" again appears (twice).
JM: Criticism of the cautious approach taken by science noted again! You see this as a general fault of science while I view this as an essential component of the scientific method. The reason that ye-creationists take this tact in argument is because they have an absolute (and therefore quite untestable) faith in their beliefs. It is natural to find fault with an approach that is more cautious and so we find this approach to debate quite frequently in creationist writings. Fortunately, history has already judged which approach is superior in answering questions about the natural world and the clear victor is the cautious and tentative approach.
Wolf et al. also write in the Conclusions, ". . . we believe that apatite thermochronometry can yield new insight . . .". Note the word "believe." Its rather close to the word "belief," a word which "is frequently associated with faith." We may be certain that this is the case, for Eugenie Scott herself has said so. (See "Twelve Tips for Testifying at School Board Meeting," by Eugenic C Scott, Reports of the National Center for Science Education, 20(1-2):35; Jan-Apr 2000; Point No. 6.)
JM: Ahh, the semantical argument. Wolf et al. were not required to sign an oath of faith regarding this statement nor will they be reluctant to accept a careful study refuting their position. Most scientists would read the statement as "This is our best conclusion". One also has to wonder why ye-creationism requires an oath? Indeed, if the weight of the evidence were in favor of a young earth, no oath would be necessary. The oath is required because all the evidence points another way and has for over 200 years! The reason an oath is needed is because there is nothing else!In a 1997 paper, the same Wolf et al. write in their abstract that they found helium ages that "are younger than ages obtained by other dating techniques." The Introduction begins, "Thermal histories of rock masses can be deduced from the analysis of parent/daughter systems . . .". To "deduce" means "to infer from a general principle." This is just another way of saying "interpreted" isnt it? JM: You seem obsessed with this word. My question remains; what method has led to more discoveries; absolute unchanging dogma requiring oaths or tentative science?] On page 68, col. 1, they discuss some complications with their proposals, and say the age they found "might be inaccurate, possibly suffering from excess He, a phenomenon known to occur at least in some hydrothermal apatites ." Now we are back to "excess" He. In their conclusions (p. 68, col. 2) they explicitly use the word "interpretation." ("Assessment of (U-Th)/He thermochronometry: The low-temperature of the San Jacinto mountains, California," Geology, 25(1):65-68; Jan. 1997) JM: Im waiting for criticisms other than a semantic argument that hints at conspiracy. Do you have one? Finally, we come to "Modeling of the temperature sensitivity of the apatite (U-Th)/He thermochronometer," by Wolf, et al., Chem Geol, 148, 105-114; 1998). In their Introduction they write, "Laboratory diffusion measurements indicate that radiogenic He is retained in apatite under mean Earth surface conditions, but is lost by diffusion at only slightly higher temperatures ." If things warm up very much you are going to be losing that helium, thus interfering with your dating methods accuracy.
Also in the Introduction (pages 105-106) we read, "However, in many cases, the assumptions required for application of the closure temperature concept, such as simple monotonic cooling, are not met. This is particularly true at the low temperatures relevant to He in apatite, where the tectonic and erosional processes which expose rocks at the Earth surface are likely to yield complicated cooling histories." Now we are struggling with un-met assumptions, as well as the diffusion (loss of He) problem that occurs at low temperatures. (This is the Wolf, et al. paper that addresses solar insolation and forest fires. I addressed these points earlier in the posting.)
JM: No, you didnt. You left out key information regarding some of their statements, attacked their choice of words and hinted at a conspiracy. Nowhere, have you addressed the science!
Lets go back, now, to Joe Meerts comments about the RATE projects observations on (U+Th)/He dating.
Joe quoted the ICR/RATE premise and wrote (within the dashes):
Helium Diffusion Rates
"Acquisition of data on which to base a claim that the amount of helium in rocks today should not be so high if it was produced by nuclear decay over millions of years. If helium was produced within the most recent thousands of years, it would be expected to still remain in the rocks as observed"
Mumbo-jumbo. The claim here appears to be that there is too much helium in the rocks today. The RATE Group does not provide an explanation of what is too much. It states rather matter-of-factly that it is too high. The rate of helium diffusion from minerals is not a simple linear process1,5,6. Once again, the RATE Group begins with a false premise that it intends to prove by misinterpretation of the data and an incomplete reading of the literature. Remember: Misinterpreting Science is not the same thing as disproving science.
Well, what about the amount of He in present-day rocks? It does look like the RATE group is saying there is too much He today, and Joe writes, "The RATE Group does not provide an explanation of what is too much. It states rather matter-of-factly that it is too high." This is an accurate representation of what the RATE group wrote. However: one of the papers I cited (Lippolt, et al., 1994) specifically referred to "extraneous" helium. In this context, extraneous means extra the level of He was too high, which is what the RATE group said. It would appear that there is some support for the RATE suggestion that there is too much He in the rocks. I did not read the entire Lippolt et al. paper, but in their Conclusions they also do "not provide an explanation of what is too much," even though they do again mention the need to watch for extraneous He.
JM: Yes, they did. As I pointed out, you did not read the article. This is also not the argument made by the RATE Group, you are mixing apples and oranges. The RATE Group is arguing that Helium retention in the rocks is absolutely high because the Earth is young. Lippolt et al. are arguing that additional radiogenic helium might be incorporated into some rocks, but will only affect the ages providing certain thresholds are met (which they also describe). These are not the same arguments and do not support (or refute) the RATE claim because they have little to do with the RATE claim.
If anything, there may be too little He in the apatites tested. All the papers repeatedly refer to the problems associated with diffusion, especially at low or ambient temperatures. Whether there is too much He or too little I do not profess to know. It is obvious, though, that the amount of He and the degree of diffusion is a serious problem, and that (U+Th)/He researchers are well aware of it. The RATE group can hardly be faulted for its invocation of uncertainties about the proper level of He when orthodox old-earthers, publishing in old-earth-accepting journals are also uncertain about the proper levels of He.
JM: Thats not what I am faulting them for. What I am arguing is that this line of argumentation will not be able to establish a young earth. In fact, despite Helium loss in the samples, they are all coming out to be much older than 6000 years. Adding extraneous helium only makes them older. Wheres the youth!
Joe also writes, "The rate of helium diffusion from minerals is not a simple linear process" (citations omitted). This is true, but it is irrelevant. The RATE group did not say, imply, or insinuate that the diffusion rate was (or was not) linear. The group said nothing about the rate at which He is lost to diffusion. Joe wrote that the RATE group "begins with a false premise." What is the alleged false premise? That diffusion is a linear process? To reiterate, the RATE group did not say it was (or was not) a linear process.
I still agree with Joe (as I said in an earlier posting) that the RATE premise is "mumbo-jumbo." This is due in part to the writers use of improper verb tenses, and in part to the premises being confusing and poorly written at least I find it to be confusing and poorly written. Whoever wrote the premise obviously was not striving for precision of speech or freedom from ambiguity.
JM: So after all this misrepresentation of scientific articles, you agree with my general conclusion! One has to wonder what form of twisted logic was followed to do that!
Joe also seems to admonish the RATE group for an "incomplete reading of the literature." Based on what I have seen so far of (U+Th)/He dating papers, I will have to admonish Joe for the same shortcoming. In his assessment of the RATE "premise" he does not in any way allude to any of the subtleties in this method of dating, nor to the uncertainties of its findings, nor to its falling into disfavor for many years because it came up with dates that were too young. I am not suggesting that he should have written a dissertation on the subtleties. I do think that he could have acknowledged the difficulties caused by diffusion, and let his readers know that this method is not cut-and-dried, which is what his comments seem to imply. (If Joe has read as much of the literature as he probably would like the RATE group to have read he did nothing to present it in his assessment of the RATE "premise.")
On the other hand, I will say on Joes behalf that it would not surprise me at all if I were to learn that the RATE group is guilty of an incomplete reading of the literature. No, this would not surprise me at all. And, it may well be guilty of "misinterpretation of the data." (Oops. Theres that nasty word again: "interpretation.")
JM: So why did you not read the literature or cite it completely? You admonish me for not reading the literature, but indeed I do read the literature and my main point regarding this method (or tact) is that ICRs RATE Group is starting with a false premise. I did not discuss the intricacies of the method because there is no need to address the intricacies of the method on my web page. I am not defending the U-Th-He method, I am attacking the RATE Groups premise.
Note: The Discussion of the RATE Group Experiments can be found here.
Added July 25, 2003: One of the recent
claims is that coal also contains C-14 that allows it to be dated. An
article on coal and C-14 is posted
at the TalkOrigins site http://www.talkorigins.org/faqs/c14.html and is worth a look.
Andrew Snelling (of Answers in Genesis)
claims that a piece of 'wood' obtained from a Triassic
sandstone yielded a C-14 age that was much too young for it to be a Triassic deposit.
In doing so, he claims to have invalidated the C-14 dating method and the old earth
time scale. Snelling has not submitted this article for peer-review, nor does he
apparently have any intention of doing so. The paper is for dissemination to other
young-earth creationists. As you read, please note that the principle question
regarding these studies is the level of contamination in the samples. Snelling NEVER
addresses the fundamental objection.
Photo of Alleged Sample (See above reference)
Intrigued, I decided to pursue this matter in a bit more detail. I wrote to the head of Geochron Labs Radiocarbon group (Dr. Cherkinsky) who responded to my inquiry with the following e-mail:
Sent: Tuesday, January 09, 2001 6:58:55 PM
To: Meert Joe
Subject: Re: Some questions
I remember this sample very well. So they called it "wood'? It wasn't wood at all and more looked like the iron concretion with the structures
lightly similar to wood. I have told about that to submitter, but anyway they wanted to date the sample. I think maybe this concretion was formed significantly later than Triassic period and I do not think that is a very rare case when you can find younger formation in the old deposits especially if it is sand or sandstones which
could be easy infiltrated with oil solutions. If you have more questions please let me know.
Radiocarbon Lab Manager
Snelling had a fit when I posted this to a Cre-evo discussion board and insisted that it (a) was wood and (b) he has proof in a drawer somewhere. Aside from the obvious poor documentation by Snelling, he made the following statement:
"If it wasn't a sample of fossilised wood, then apart from Dr Cherkinsky's obfuscation, how do Drs Meert and Cherkinsky explain its radiocarbon content? Quite clearly their opposition to the results of this genuine research study are more to do with their a priori belief about the age of the earth and its rock strata than with science. The evidence they are trying to cover with a smokescreen of personal abuse instead speaks for itself. "
Is this a valid criticism? It might appear to be, but there are several clues from Snellings own hand that indicate there are problems with this analysis. Please note, Snelling seems puzzled that an iron concretion could give a radiocarbon age. This is not at all uncommon and a cursory look at the literature would have given Snelling something to think about when he noticed the iron present in the sample. The first is Snellings description of the 'wood' impregnated with silica and hematite. Hematite is an iron oxide (rust essentially). Snelling adamantly maintains that the sample is wood from the Hawkesbury Formation Indeed, carbonized wood and plant matter is reported from the Hawkesbury Formation, but Snelling provides no detailed description of possible subsequent alteration---with the exception of the 'impregnated' sentence above. However, this alteration is probably the key to the 'dilemma'. It likely explains why Geochron labs identified it as an iron concretion with structures resembling wood. The replacement of wood by iron and silica would give it just that appearance. This alteration immediately calls into question the use of C-14 dating on the sample. There have been studies on iron concretions and 'dating' of them. For example Bird et al. (1994, The Carbon Isotope Composition of Organic matter occluded in iron nodules; Chem Geol, 114) states:
This study presents 13C and 14C results for soil organic carbon and carbon occluded by iron nodules from a quaternary soil profile developed on basalt in western Victoria, Australia. The results suggest that the 13C-value of organic matter in the iron nodules is directly inherited from the surrounding soil profile without isotopic fractionation, and that therefore the 13C-value of organic matter occluded by the iron nodules can be related to the vegetation present during nodule formation. However, 14C results suggest that iron nodules are not closed systems with respect to organic carbon, and that even chemically resistant immobile particulate carbon (of probably microbial origin) has been added to the nodule carbon pool since formation.
Interestingly, the sample run in that study gave d13C values typical of organic material (as in the Snelling study) and the iron concretion also gave radiocarbon dates due to contamination. For example, nodules in the Bird et al. (1994) study gave d13C= -24 0/00. In this study (from a different area of Australia), the nodules gave C-14 ages between 7470-1960 14C (before 1950). So, despite Snelling's incredulity about how one obtains an age from iron concretions, the answer is with some contamination. Therefore, although Snelling claims that cleaning would remove all possible contaminants, the paper by Bird et al. (1994) shows that this is not the case for iron concretions because they do not remove microbial contamination as clearly demonstrated by the study.
Furthermore, it is this microbial contamination that is responsible for the 'apparent age' of the sample. We have Snelling admitting that the sample was altered (silica and iron-rich), the radiocarbon lab manager-- whose specialty is C-14 dating of woody material-- stating that the sample appears to be a concretion and a study that shows quite clearly how such samples can give 'dates' through contamination. Unfortunately, Snelling keeps the data locked in a drawer and refuses to submit it for peer-review. Until he does so, recent contamination of the sample remains the most viable explanation for the supposed 'anomalous' dates. Note, this is not a case of he said, she said. This is a case of poorly documented science on the part of Snelling. He wants to overturn all of geology, but does not want to properly document the evidence.
It is also very likely that Snelling repeated this error half a world away. In his 'study' of the Marlstone rock bed in England, he also reports anomalous C-14 ages in an area known to contain younger iron oxidative products. Of course, Snelling also closely guards these data in some drawer and refuses to submit the publication for peer-review. Note that in the picture included in the Snelling article, it is impossible to determine whether or not this is wood. Fossil wood is reported as a rare occurrence around Banbury, so it is possible that Snelling has indeed sample fossil wood, but the evidence provided in the photo is scanty.
Photo from paper Pure Limonite
A recent paper (there are a number of these) by Deyell et al. (2000, Can J. Earth Sci., Age and Origin of advanced argillic alteration zones and related exotic limonite deposits in Limonite Creek area, central British Columbia) shows that limonite will indeed give C-14 ages as it replaces plant material. Even if we assume that Snelling has indeed sampled fossil wood of Jurassic age, no carbon should be left in the wood and therefore it is imperative in his 'test' to fully document that there is no contamination present.
Snelling lists 4 reasons why contamination can be ruled out. He states:
(1) since labs all obtained similar ages this rules out
That is simply twisted logic. If the contamination is all of a similar age, then the data will be similar.
(2) he talks about levels of 'unavoidable contamination'
This seems to cancel the logic in point number 1, he also 'invents a 0.2% value out of thin air, contamination could be more and he needs to document that HIS samples contain no more than 0.2% of contaminants. Cherkinsky noted (in a personal communication) that iron deposite contain up to 15% organic matter. Furthermore, if the sample is indeed a Jurassic wood any contamination would be a problem.
(3) He states the the d13C values are indicative of organic plant material.
This is correct but as noted above contamination by younger organic plant material will still result in 'characteristic d13C values.
(4) Snelling asserts that if anyone claims contamination
it would be an ad-hominem attack against respected laboratories.
One wonders why Snelling might mention this since he claims (kind of) that the samples are not contaminated. Perhaps, it is a pre-emptive strike since he realized that he has not fully documented his case for no contamination? Unfortunately, contamination can occur at any point along the way including during formation of the sample. As noted above and again below, there are cases where contamination cannot be removed. Hence, not a single one of his 4 reasons involves unequivocal proof that his samples were not contaminated! It is also not a slam on the laboratories.
Let's move on to the specifics of this second case. Snelling's description of the site reads:
"When sampled, the fossil wood readily splintered, diagnostic of it still being woody in spite of its impregnation with iron minerals during fossilisation."
The Geologic description of the site (Geology of the Country around Banbury and Edge Hill, Edmunds et al., 1965, GS Great Britain) describes the section as follows:
"Locally the Marlstone rock bed is known
as the Hornton Stone and it has been quarried for ornamental purposes in three large
A section is described as follows (pg 47 of the report):
(1) Red soil with ironstone debris (1 foot)
(2) Shelly, false-bedded oolite (3.5 feet)
(3) thinly bedded, shelly, calcitic sideritic chamosite ooilite with partings of limonite chamosite and oolite (6 feet)
(4) Calcitic sideritic siderite oolite (4 feet 3 inches)
(5) limonite (0.5 ft)
(6) calcitic sideritic chamosite oolite (10 inches)
(7) limonite (2 inches)
(8) Calcitic sideritic chamosite oolite (10 inches)
(9) calcitic sideritic chamositic siderite oolite with limonite partings at the top and bottom (1.5 feet)
(10) Shelly siderite limestone (5 feet)
Under 'Petrography' (a study of the makeup of the rock), the authors note that some of the limonite was formed contemporaneoulsy with the deposition of the rocks, but they go on to say:
"Nevetheless, it is likely that most of the oxidation of the Marlstone rock bed is of recent origin.
Snelling does not demonstrate that the fossil wood was
'impregnated during fossilisation' nor does he demonstrate that this 'wood' is in-situ.
Limonite will also 'splinter'. The photo is not helpful in either regard and
in fact, the small deposit shown in the photo (reported to be an end-on belemnite) looks
like a coating of limonite rather than a fossil. Snelling expresses some concerns
about finding land plants interbedded with ammonites and belemnites and calls on a global
flood to explain the occurrence. An equally valid explanation is that the wood is
not in-situ (i.e. did not form at the same time as the limestone) or since oolitic
limestones form in very shallow (near-shore) environments, the wood may have floated
there. His assertion that the wood shows roots etc is not supported by any firm
documentation. Rather than reflecting damage to the old earth hypothesis, it shows
that Snelling is not a very careful scientist as he once again does not document his
results. Snelling needs to show conclusively that the only explanation for this is
that (a) the wood is really wood; (b) it is in-situ and not younger; (c) that his sample
contained no limonite or other contamination which is present throughout the
outcrop. The onus is always on the person making extraordinary claims to document
their case. Snelling can prove me wrong by producing the data (preferably with SEM
photos and elemental analyses). Of course, he won't do this and it is much more
likely that he will fume and cry foul. I will happily retract this page if Snelling
produces the data. Will he retract his story if the elemental analyses and SEM
photos disprove his hypothesis? Note: These data would be absolutely required by
peer-reviewed journals in light of the known complications of C-14 dating in iro-rich
deposits so I am asking the same thing any good editor would ask.
SNELLING ANSWERS (SORT OF)
Please NOTE: The following was posted on an internet bulletin board by someone claiming to have spoken with Snelling. The person who posted this to the board provided no evidence that he/she had actually spoken with Snelling so caveat emptor. However, the points raised by the person (Snelling or otherwise) do not answer the relevant questions regarding the sample.
AS: I don't want to waste valuable time on the Joe Meert accusations and the discussion you are having over the net. You are quite correct in insisting that Joe's case stands or falls on Dr Alex Cherkinsky producing a copy of his claimed correspondence with me (which we know doesn't exist). You are also correct in emphasising that in the lab report which came to me there made no mention whatsoever about the sample being unsuitable for radiocarbon analysis.
Cherkinsky can be credited with the impetus for delving further into this issue. As
noted, this is not a case of he said, she said. This is a scientific argument and
the onus falls squarely on the shoulders of the person overturning the paradigm.
Now, Snelling may not like this and he may complain bitterly about it, but he has failed
to document his case. I don't want claims, I want evidence as would any good
scientist. It is also important to note (since several have called Cherkinsky's
honesty into question--and mine) that Cherkinsky claims 'he told the submitter'.
Snelling wants a letter, but Cherkinsky may have phoned Snelling, a secretary or a lab
assistant. At this point, we simply do not know. Cherkinsky was given the
sample reference number in my e-mail, so presumably he checked his notes regarding the
sample. The main point is that the contents of Cherkinsky's letter are irrelevant to
the points below as Snelling has admitted that the sample was iron bearing.
AS:However, the major point I wanted to make here are in response to the appropriateness of the sample and the sampling technique. First of all, the sandstone in which the fossilised wood was found is a tight, silica-cemented sandstone that contains no oil whatsoever, and through which no oil has been known to penetrate.
JM: Apparently Snelling thinks that oil has something to do with the contamination. This probably comes from Cherkinsky's e-mail letter, but as it turns out, oil is irrelevant in this case. The Hawkesbury sandstone is highly jointed (BMR Report The Sydney Basin) which allows fluid flow and rootlet and other microbial material penetrate the sandstone. At any rate, the relevant points are outlined above.
AS: Second, it is not inappropriate to analyse fossilised wood for radiocarbon.
JM: I don't believe I made this claim neither did Cherkinsky. It is very inappropriate not to include the full results of the analysis including documentation that the sample was not altered. Snelling did not do this.
AS:Fossilised human bones are regularly radiocarbon dated, as are wood samples from archaeological sites, etc., even if some fossilisation has occurred. The real question is not whether the wood has been fossilised, as what constitutes a fossil is a fuzzy area anyway.
JM: Irrelevant side show.
AS: The real issue is how much permineralization has occurred, that is, infiltration and replacement of the wood by silica, iron carbonate, or other chemicals.
JM: I believe the real issue-- is demonstrating that Snelling sent a sample of wood that has not been altered or contaminated. Replacement is a secondary and critical issue as outlined above. Here Snelling admits the importance of this issue, but does nothing to substantiate that the sample was not altered.
AS: Even if other chemicals have replaced most of the wood, as long as some of the original organic material has remained, fossilised wood can still be tested for radiocarbon, and as far as we young earth creationists are concerned we would expect to possibly find some radiocarbon still left.
JM: Partly true, because no one disputes the fact that wood can be dated. The problem is that the type of replacement suggested by BOTH Snelling and Cherkinsky allows contamination of the sample. If the original wood is older than ~50K years, there would be no original carbon in the wood and the lab would be measuring only the contamination. This is a critical point NEVER addressed by Snelling with the proper analysis.
AS: That was the rationale behind submitting this sample to Geochron's radiocarbon laboratory. Its validity as fossilised wood was carefully checked and was never in doubt.
JM: Actually, it is very much in doubt as the letter from Dr. Cherkinsky attests. Snelling has provided hearsay evidence to support his claim and he could rightly claim Cherkinsky's statement is hearsay. At this point both are irrelevant. It might be righteous indignation, but as any scientist worth his/her salt knows---the case rests on the evidence. Snelling can settle this by providing the SEM photos (Scanning Electron Microscopy) and the chemical analyses of the sample. I assume, as a careful scientist, he ran these critical tests.
AS: The question was whether Geochron would find any residual organic material in the sample, and therefore be able to obtain a radiocarbon analysis. Thus their lab report answered our questions.
JM: Actually it did no such
thing. The lab reported an age. Snelling would have had to do the
contamination analysis himself.
AS: Third, the question of contamination is dealt with in the lab report by the chemical treatment of the sample in its preparation for analysis.
JM: Actually, this is very much in doubt as the paper by Bird et al. (1994) indicates. The procedure followed in that study shows that the cleaning methods do not remove all contaminants in these iron nodules: The procedure for AMS C-14 sample prep is described by Bird et al. (1994) is lengthy (compare to Snellings): Here is the summary:
(1) Sieving and hand-picking of
(2) Cleaning in ultrasonic bath
(3) boiled briefly in 6 N HCl
(4) washed in distilled water/ultrasonically cleaned
(5) boiled for 1 hour in 5 N chromic acid to destroy organic carbon available to solution (soil organic matter and opal phytoliths)
(6) washed and boiled repeatedly to remove chromic acid
(7) oven dried 100 C
(8) crushed and boiled in 500 ml 6 N HCl to dissolve iron oxides
(9) residue transferred to a 300 ml HCl-HF-H2o (1:1:1) solution at 50 C overnight
(10) remaining residue washed free of HF
(11) treated with 0.1 N NaOH to remove alkali soluble organics
(12) residue ultrasonically cleaned for 30 minutes in chloroform-methanol (2x), methanol (2x) and water (2x) to remove chemically resistant solvent extractable organic compounds.
The sample still gave C-14 ages due to microbial contamination that was not removed by this procedure. Compare to what Snelling reports.
AS: Indeed, the analytical report from Geochron Laboratories described the sample as wood and under the heading 'Pretreatment' reported that 'The wood sample was cleaned of dirt or other foreign material and was split into small pieces. It was then treated with hot dilute HCl to remove any carbonates and with hot dilute NaOH to remove humic acids and other organic contaminates. After washing and drying, it was combusted to recover carbon dioxide for the analysis.'
JM: Irrelevant. This procedure will not remove all organic contamination as noted by Bird et al. (1994). If you were paying me to call the sample wood, I would do so to appease you---especially after insisting the lab run it after being advised it was not wood.
AS: Under 'Description' it was described as 'sample of wood', and elsewhere under 'Sample name' it was described as 'organic material'.
JM: Irrelevant. You need to show the evidence through chemical analyses. Indeed, in Snelling's paper he noted the presence of contamination. Is he now denying this RELEVANT fact? Poor science on Snelling's part does not require extraordinary expenditure on my part. Show us the data that proves this is uncontaminated wood. The submittal form also asks the submitter to describe the sample. More than likely the final report parrots the claims in the submission form. Snelling should produce both of these documents.
AS: So much for Dr Alex Chernisky's claims and for the arguments about appropriateness of doing a radiocarbon analysis of fossilised wood!
JM: Not quite true. Snelling and Cherkinsky have both admitted to the presence of iron in the sample. As I also mentioned, no one is debating the ability to date fossilized wood---it is a question of WHAT wood and IS IT WOOD? Cherkinsky is a trained C-14 geochronologist, Snelling is not. However, the point is that the type of contamination noted by BOTH Snelling and Cherkinsky along with the material discussed above is enough to throw Snelling's poorly documented science into the trash heap.
AS: If you feel it is appropriate to settle the matter, then I can always scan in the one page analytical report from Geochron Laboratories and send it to you as an attached file for you to post on the Internet if you want to. I have absolutely nothing to hide from this procedure.
JM: The lab report from Geochron is not at issue here. Nor is the 'age'---for what it is worth, I do believe that Geochron returned the age to Snelling as documented. The issues are the significance of the age and the possibility of contamination. Snelling has not answered those questions.
Final Note: If Snelling can indeed substantiate his case, I will publicly apologize and withdraw this material. Most scientists, when criticized respond by thoroughly documenting their case. You can see examples of these in the scientific literature by looking at comment/reply sections. If you want an example, some work I had done in 1994 was criticized and I wrote the following comment.
This is another excellent example of supposed 'creation science'. All creation science is reactionary. There is no creation model and there is no original research aimed at establishing a creation model. Creationists, like Snelling, rely on a false dichotomy and conclude that if evolution is wrong, then their narrow misinterpretation of Genesis is correct. Interestingly, Snelling has published a few articles using old-earth chronology. He, like John Baumgardner and John Woodmorappe (aka Jan Peczkis) have all published old-earth evolutionary articles in the mainstream literature while, supposedly, clinging to a young earth viewpoint. Snelling claims (essentially) that he was forced to publish old earth views. This statement is ludicrous as no one forces anyone to publish anything.
creationists recently engaged me in a discussion regarding the veracity of
radiometric dating. One of them (HF) made an initial claim that most
radiometric ages were tossed out prior to publication. In essence, this a
weak version of the scientific conspiracy theory. It can be briefly stated
as follows: "Scientists know how bad dating really is, but evolution
depends on an old earth and therefore we must hide all the bad data and publish
only the good stuff". Such a statement is patently absurd and, as
later admitted by (HF) unsupportable. Here is a brief recap of that
discussion originally aired at Baptist Boards BB. The board was shut
down for a month or so after I challenged Helen to support her accusation.
The BB was replaced with a e-mail version (often censored) to avoid 'unpleasant'
JM= Joe Meert
The first message is to bring the issue back on the new board:
I am just curious as to whether or not we will ever be presented with the evidence for discarding of radiometric ages that was made on this board in November of last year. This is a serious accusation aimed at modern science. In my experience, this is not true at all but I am willing to be convinced by a preponderance of data. Remember, published works don't count. You must supply evidence that most radiometric ages are tossed out before publication. I read lots of articles and the good are presented alongside the bad so I would like to know who these people are that are hiding the data. Anyone?
The following quotes and notes are from a number of sources and should back up the point that there are quite a few dates which are discarded where radiometric dating is concerned – they never get mentioned in any publication.
One of the most obvious problems is that several samples from the same location often give widely-divergent ages. Apollo moon samples, for example, were dated by both uranium-thorium-lead and potassium-argon methods, giving results which varied from 2 million to 28 billion years. Lava flows from volcanoes on the north rim of the Grand Canyon (which erupted after its formation) show potassium-argon dates a billion years "older" than the most ancient basement rocks at the bottom of the canyon. Lava from underwater volcanoes near Hawaii (that are known to have erupted in 1801 AD) have been "dated" by the potassium-argon method with results varying from 160 million to nearly 3 billion years. No wonder the laboratories that "date" rocks insist on knowing in advance the "evolutionary age" of the strata from which the samples were taken -- this way, they know which dates to accept as "reasonable" and which to ignore. Of one thing you may be sure: whenever "absolute" radiometric dates are in substantial disagreement with evolutionary assumptions about the age of associated fossils, the fossils always prevail. ]http://www.gennet.org/facts/metro14.html
A collection of radiometric data sets were
reanalyzed to determine their relevance to defining previous sea level
positions. Criteria for analysis included core location, material dated, and
position with the core sequence. Unsuitable dates were removed from the data set
based upon five possible parameters: reworked shell material, peat compaction
(invalid or uncertain vertical placement), root contamination, insufficient
sample or positioning data, or self-conflicting data. The
reduced data set is shown in Figure 13. www.geology.iupui.edu/research/sedlab/data/Lenore/sea%20level.doc
(in checking links, the article this was part of appears to have been pulled. Interesting… )
Another disconcerting fact: the "correct" ages which appear are the result of a selection (Holmes, 1965), the
author having only accepted the "best values" (those confirming Lyell's stratigraphical scale), rejecting the
others as "anomalous." http://www.rael.org/int/english/evidence/evidence/body_evolution2.html
Dave Tyler sent me the following in a private email:
In June 2000, Paul Garner wrote: "Last night I
spoke at Histon Baptist Church, Cambridge on "Creation or evolution?"
.. .. Another gentleman was a geochemist at the British Antarctic Survey,
working in the field of geochronology. He is a Christian but convinced of an old
earth. We had a good conversation afterwards, and he said that although he
disagreed with my position, he felt that I'd "made a good case for
it". I was encouraged by some of what he had to say about radiometric
dating. This is his field of work and so he was very knowledgeable on the
subject. In his opinion, rubidium-strontium (Rb-Sr) isotopic data are very
difficult to interpret because false isochrons are so common, and
potassium-argon (K-Ar) dating is so
fraught with problems that "nobody believes K-Ar dates" (his words) anymore. However, he pinned his confidence in radiometric dating on other methods, such as uranium-lead (U-Pb) dating of zircons - which has a whole set of problems all of its own."
The point I would make here is that most people would never know from the literature that false Rb-Sr isochrons are so common, and that "nobody believes K-Ar dates". Such knowledge comes from insiders who see the results before they are published.
In a private email from Dr. Tim Standish at GRI:
In Arial Roth's book he cites Runge et al 1973 “Radiocarbon chronology and problems in its interpretation for Quarternary loess deposits-South Canterbury, New Zealand”, Soil Science Society of America Proceedings 37:742-746. in which they give a sequence of C14 dates of soil layers going from top to bottom of 9,900, 12,000, 27,200, 17,300 and 15,650 years. Obviously the last two dates can't be right and they are dropped out of a subsequent paper, Tonkin et al. 1974. “A study of late Pleistocene loess deposits, South Canterbury, New Zealand. Part 2: Paleosols and their statigraphic implications.” Quarternary Research 4:217-231.
The following came in from a friend who is a graduate student now:
This shouldn't even be a debated issue, because it's a fact. I used radiometric dates in my masters thesis, and if they seemed to be "off" a bit, they were simply said to be wrong. Of course I did what I was told to do, but my feeling was that the commonly accepted wisdom is that the methods are fallible, and so if the date is wrong, no worries! My question then becomes, how do we know when it is right? It's not talked about much. God bless!
A personal friend of ours is Dr. Graham Mortimer:
Barry and I both took the time individually to talk with him on the phone about the discarding of dates. Graham works with zircon crystals. He stated that about 15-20% of the dates were considered anomalous and thus not used. Keeping in mind that zircon dating is probably the most reliable and yet, as Andrew Snelling has mentioned, still frought with problems
it is quite reasonable to assume that more than 15-20% of the dates obtained by other methods would be considered anomalous/unreliable and thus not used. I am willing to take back “most” as me believing something I was told without checking it myself, but the more I ask and read, the more aware I am of two things: 1. There are quite a number of dates that are discarded by lab or researcher or both as being wrong from the start 2. and almost no one is willing to talk about it.
Helen, once again your answer is laced with 'what-if'
scenarios and a few unverifiable personal communications. The evidence you do
seem to cite is from published sources. Since I not only conduct
geochronological studies but also review geochronologic studies, read the
literature and work in a University with two geochronologic labs, I think that I
am quite familiar with the mode of operation. However, let's assume, for the
sake of argument that 10-15% of ages produced are anomalous. That leaves 85% of
age determinations that are not. How do you explain the 85% of ages that are not
anomalous? You must also remember that we are dealing with natural systems where
alteration can and does take place. Geochronologists have devised a number of
ways to deal with alteration of systems and do so on a continual basis. I went
back and looked at the percentage of age determinations that I personally have
worked on and less than 5% are troubling. Each one of those 5% have a reasonable
explanation for why they
didn't work (from excess argon clearly evident in the plateaus to severe hydrothermal alteration of the samples). In any case, your argument that most dates are toosed out before publication fails yet again. Think about it for a minute. If geochronology was so utterly unsuccessful, the geologic community would stop using it. They do not. The ages produced in labs have verified field relationships time and time again. This fact argues my point much more strongly than your accusation of subversion on the part of the geochronologists. Finally, I might also add that none of these anomalous ages points to a young earth. You would think that somewhere in that 10-15% of anomalous ages that you claim exist, there would be a bunch of 6000-10000 year old ages. Why don't you produce some of this evidence? In fact, let's assume that your 'friend' Mortimer thinks that dating is unreliable. Why
does he continue to use the method and publish articles about the method? Seems like if something is so horribly awry with radiometric dating, Graham would stop using it and call for its abolition. Yet, there he is publishing away on the subject and continuing to use it on a daily basis. Seems like that would be such a waste of time for such an awful technique! I must
conclude on the basis of your arguments that you really don't have any hard data available to substantiate your claims. Your insistence is simply that geochronologists are dishonest. I find that absurd.
My recollection is that the great majority of isotopic
dates are K-Ar dates, so that if 85 percent of dates agree it could be largely
because K-Ar dating agrees with itself much of the time. A better statistic
would be how often different dating methods (different parent and daughter
substances) agree on the same sample or formation.
I recall that there is a technique called "mineral isochrons" in which different minerals from the same rock are dated by the same method, say Rb-Sr dating or U-Pb dating -- I'm not sure which would be appropriate. This can be treated as an isochron since if all minerals cooled at about the same time, any changes in parent to daughter substance would have arisen since then (if the system were not disturbed etc.). One would expect different minerals to absorb different amounts of parent and daughter substance on cooling so one should get a good isochron. At least I can't think of anything that would throw off this method. So my question is how often are such "mineral isochrons" or should I say "multiple mineral isochrons" done? I read that they are not done much because of the difficulty of isolating the different mineral fractions, but if they give more reliable dates it might be worth the effort. What would be especially interesting is if two mineral isochrons from the same rock, using two different parent-daughter substances, gave nearly the same date -- has this been found? If such a method gives "good" dates then either the sample is old or decay rates were faster in the past.
My recollection is that different methods often agree on certain meteorites, and maybe even on certain very old (appearing) rocks on earth, but much less often in the Phanerozoic (Cambrian and later).
(Let me also add that it is not so easy to know whether the dates are biased -- if geologists believe zircons to be more accurate then it would appear that more and more of the dates in the literature would be from zircons. Thus the proportion of the dates in the literature could be skewed towards methods (or sub-methods, or formations) that seem to give more accurate results, and thus the system could be in some sense self-fulfilling. Of course this is just speculation but it's hard to seehow this would not bias the results.)
What I find absurd, Joe, is that you don’t seem to
actually read my posts.
1. I did not say geochronologists are dishonest. I think they are being quite as straight as they can be in line with the faith in long ages and the fact that almost all radiometric data points to long ages at the very least.
2. Dr. Mortimer does not think the dating is unreliable. He simply said that there was a certain percentage of the dates which were considered unreliable. There is a big difference.
3. I would not expect short ages out of radiometric dates for the very reason of the change of decay rates in the past – this change from much faster than now to now would guarantee that few or no dates would indicate a recent age.
4. I think the references pointed out quite clearly that when field assumptions and radiometric dates differ the field assumptions win.
5. I retracted, with apologies, the statement that MOST dates were thrown out and admitted I had understood or been told wrongly about this.
To Dave Plaisted
Your intuition may be correct that most geochronologic data available are K-Ar determinations. I would not bet against that conclusion, since it was one of the first and cheapest methods for determining ages. It also has a wide range of applications so the cheapness and the range made it extremely popular. It still is used quite a bit today and it does quite a good job. Today, our understanding of closure temperatures and the behavior of the K-Ar system is much better constrained by using the 40Ar/39Ar method. In general, most of the K-Ar ages that I have personally examined are quite robust. In the cases where the ages seemed a bit askew based on more recent datings, the 40Ar/39Ar system usually reveals the reason why the K-Ar ages were skewed. In fact, the 40Ar/39Ar has been a nice addition and way to double check for isotopic disturbances in the K-Ar system.
In terms of your experiment using different isochrons for different minerals in the same rock, it has been done a number of times (some of these can be gleaned from the database in Meert, 2002). You must remember a few things about such an experiment. The first has to do with the idea of isotopic closure. Different isotopes close under different conditions (depending on the isotope, temperature and grain size). Let me give you two examples that I am personally familiar with. There are many others out there, but I am at home and these are both in my brain. The first is from the Carion granite in Madagascar. The granite has been dated using a variety of methods. U-Pb SHRIMP ages and U-Pb evaporation ages overlap with small errors at ~535 Ma (Kroner et al., 2000; Meert et al., 2001). The U-Pb system closes at temperatures well above 850 C. 40Ar/39Ar studies on hornblende and biotite and K-feldspar yield younger ages of ~513 Ma and ~480 Ma consistent with their experimental closure temperatures of 500 C and 350 C respectively. Multidomain K-feldspar studies yield younger ages and cooler temperatures that helped us develop a composite cooling curve (see http://www.indstate.edu/gga/pmag/radiomet.htm). This study was done in conjunction with a paleomagnetic study on the same rocks. A pre-existing apparent polar wander path had been established for the continent of Gondwana (Meert and Van der Voo, 1997). The pole for the Carion granite fell on this APWP at 510 Ma. Temperature studies on magnetic minerals within the granite combined with the cooling curve for the granite yielded a magnetic blocking age of 508 +/- 11 Ma entirely consistent with its location on the APWP (details are described in Meert et al., 2001a, 2001b).
A second study that has been done using multiple isotopic systems, in multiple labs over a number of years resulted in wholly consistent and overlapping ages for the Fen carbonatite complex in southern Norway. This study is also described in the above link. Such agreement between systems and labs is pretty tough to refute without calling on conspiracy or some miraculous (and yet undescribed physics). It may happen, but a much simpler explanation is that science has it right and radiometric dating does, indeed, work. As for your assertion that radiometric dating is better for older rocks, I’d love to see data confirming that. As far as I can tell from my knowledge of the literature, it works well across the board. In addition, given that the longer rocks are around, the more likely the possibility for younger disturbance, I would have anticipated the opposite assertion. That is younger rocks should yield the most consistent ages. The best part about the whole process is that we can now tell, with some ease and care, when isotopic systems have been disturbed. In fact, some of these thermal disturbances have helped us decipher tectonic histories with greater precision than ever (see Meert, 2002 available at http://www.clas.ufl.edu/users/jmeert). I would indeed argue that radiometric dating is healthy, happy and wonderfully consistent with the rock record.
Finally, let me state that while it is time consuming to separate minerals, it is not all that big of a deal and there are many more Rb-Sr mineral isochrons generated now than previously. This is in response to valid criticisms regarding the co-genetic assumptions of whole rock dating. I don't think there is anything inherently difficult about separating minerals at all.
Thanks for withdrawing the blanket claim against radiometric dating and for acknowledging that science, for the most part, is a noble pursuit. As I mentioned, even if we assume your 15% bad age estimate is correct, that still leaves 85% supporting the method. As I also mentioned above, I would guess that we can explain the anomalous behavior in 90% of those 15% of bad ages. This is part and parcel of the method. We constantly check and double check the results for signs of isotopic disturbance. What constantly amazes me is how robust the data really are. Radiometric dating is attacked by creationists quite often because it is such a powerful tool for showing the age of the earth. Young earth creationism, in particular, falls apart in the face of radiometric data and they must maintain that it doesn’t work. At the same time, there is very little evidence available that supports the notion of a young earth from the radiometric side of things. I don’t fault you for trying to disprove the methods because you have to. I just hope that the arguments amount to more than innuendo and slander against geochronologists. Most of the ‘case-studies’ conducted by creation scientists suffer the same problem. None of the scientists are trained in the field and laboratory methods and it causes misinterpretation of the data (see http://www.indstate.edu/gga/pmag/crefaqs.htm). I notice that the RATE group at ICR has hopes of overturning radiometric dating, but their methods are also somewhat suspect at the moment (see http://www.indstate.edu/gga/pmag/rate.htm). Still, I know that radiometric dating is a big threat to the young earth creationist community and they must continue to attack it at every opportunity. So far, not much has come of the attacks, but at least there is no lack of trying.
As for your earlier innuendos based on e-mailed accounts of personal recollections, I can tell you that K-Ar ages are viewed within their full context and the statement that 'nobody trusts K-Ar ages' would mean that they would not get published, yet they are. As with all isotopic studies, the authors must document the proper tests so that the data can be fully evaluated.
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[This is the answer to the question.]