"An equally strong objection to the uranium-daughter hypothesis in uranium poor (p.p.m. or less) minerals is that many Po halos (such as the 'Spectacle' halo [from Silver Crater]) are located in the interior of large pegmatite crystals as well as in small granitic mica flakes where they are often more than 10 cm and sometimes much less than 100 cm away from a significant uranium source (Fremlin and Gentry, 1975, p.270)."
This is quite an extrordinary claim to make for four reasons: 1) it contradicts Satterly's observation of betafite within some of the biotite; 2) it shows that Gentry knows it is a pegmatite body and therefore MUST be intrusive; 3) it admits that heat, like from a metamorphic event, erases halos; and 4) it acknowledges the proximity of radioactive minerals.
In our phone conversation in March, Gentry claimed that the sedimentary rocks cut by the dikes and pegmatites are "pristine", that they were created during creation week, and that they were later reworked during the Flood. He gives us a time-frame for all this to occur in his book. He says:
"The Creator, after calling the chemical elements into existence , might well, in the next instant of time, have formed those elements into a liquid, and
then immediately cooled that liquid so that it crystallized into the granites containing the polonium halos. These granites would have been created instantly and yet still show the characteristic of rocks that crystallized from a liquid or melt (Gentry 1986, p.129).
Was then, the halflife of 218Po -just three brief minutes- the measure of time that elapsed from the creation of the chemical elements to the time God formed the granites (1986, p.32)?"
The question I ask is why did Gentry choose Po218's halflife of 3.04 minutes for this "measure of time", and not Po210 (of which these are the most abundant halos) at 138 days or Po214 at .000164 seconds? Was this choice rationally, arbitrarily, or Biblically based? Regardless which one, this is an Omphalos (creation with an apparent past or age) argument. In fact, a look now at the whole Shield will indicate how much must have been created "POOF!!"-style with the appearence of age.
Precambrian Geology and Instantaneous Creation
A great deal of work has been carried out on the Precambrian Canadian Shield. The Shield is made up of seven distinct geological "Provinces" --west to east from the Northwest Territories to Quebec in an arc around Hudson's Bay: the Bear, the Slave, the Churchill, the
Superior, the Southern, the Grenville, and the Nain. Ontario, where Gentry's samples came from, includes three of
these provinces. The Superior, situated in northern Ontario, is the oldest (all isotopic ages are greater than 2,500 Ma and hence is Archean) both radiometerically and structurally and consists of many types of metasediments and several types of metavolcanics intruded by a variety of igneous bodies. The Southern Province, which rests unconformably (with fossil soil) on the Superior, is mostly folded metasediments intruded by some granites and is middle to early Proterozoic (all isotopic ages are between 2,500 to 1,800 Ma) in age. The Grenville, located in southern Ontario, is the youngest Province and is late Proterozoic (all isotopic ages are 1,500 to 900 Ma). It consists mostly deformed metasediments in the north, a large metamorphosed intrusive gneiss complex (called the Algonquin Batholith) in the middle, and the Grenville Supergroup in the south. The Genville Supergroup, which contains Gentry's locations, consists of metasediments (mostly metamorphosed limestone which is marble) and metavolcanics all intruded by igneous bodies of various types.
Figure 5 diagramatically shows the geological relationships of part of the Shield and the location, in relation to the geology, of Gentry's Faraday samples. Let me emphasize that these relationships are not based
primarily on the "uniformitarian principle" but on hard-won field observations over almost 100 years of work by hundreds of geologists. At the bottom-left of the figure is a block diagram of Fig. 4. The pegmatite dikes cut a gabbro (shown at the bottom right), which cuts different types of metasedimentary rocks. These metasedimentary rocks can be shown, in the field, to rest in a complex way on metavolcanics around the Madoc area south of Bancroft (middle block). This, in turn, rests unconformably on the metamorphosed Algonquin Batholith, which intrudes the deep- and shallow-water metasediments to the north (top block), which abuts (by a major fault) and partly rests on the metasedimentary column of the Southern Province, which rests unconformably on the "greenstone" metasediments and metavolcanics intruded by granites, which abuts the metasedimentary and gneissic belts to the north in the Superior Province. So if Gentry's claim of created granite is valid, then this entire sequence also must have been instantly created --in "just three brief minutes". This is not science, but is a monumental example of Omphalos!
What is also interesting is that Gentry has been told in the past, in a general way, that granites are intrusive rocks and that the oldest rocks on Earth are sedimentary and volcanic (Awbery, Personal communication, 1987 and Dalrymple, Personal communication, 1986 and
letter to Gentry, April 1987). Gentry has invariably sluffed off the comments or claimed he had an answer, but never gave one.
In his book Gentry talks of "pristine sedimentary" created rocks which look as though they were intruded by granites. When Gentry phoned me (unfortunately, Gentry has
never responded to my letters in any manner other than phone calls) after I sent him a copy of this paper in preliminary form I asked him about these sedimentary rocks. He claimed that metasedimentary rocks show no clear origin because of their recrystallization. This is flat wrong and I told him that many of these metasedimentary rocks show clear and unambiguous sedimentary features like clastic grains, cobbles, ripple marks, mudcracks, bedding plains and, most important, stomatolites. He had no answer.
In the phone coversation I had with Gentry in March he tried to claim that all of the rocks of the Shield could have been formed on the first day of creation. Here are some excerpts from his book on this point.
...only a few minutes elapsed time from nucleosynthesis to the formation of the solid earth. ...a virtually instantaneous creation of the earth (1986, p. 49).
These [Po containing] granites would have been created instantly and yet still show the characteristic of rocks that crystallized from a liguid or melt (p. 129).
...the primordial Earth being called into existence on Day 1 of creation week about 6000 years ago. ... The Precambrian granites show evidence of an instantaneous creation... (p. 184).
...the Precambrian granites are identified as rocks that were created almost instantly as part of the creation event recorded in Genesis 1:1 (p. 280).
Since his dikes are demonstratably the last rocks to form in the Shield then, by his reasoning, the entire Shield must have been "instantly created". Omphalos!
Sequence of Rock Formation
I confronted Gentry with the information about dikes by sending him some of the references and in subsequent phone conversations from him in Feburary, March and April of 1987. In a phone conversation with him on April 12 he told me that the sequence of events in the area was not what I told him it was, but that the intrusive rocks were first and the sedimentary rocks were last to form. What made him the most anxious were the stromatolitic horizons recently found just south of Bancroft in the marble units cut by the Faraday Gabbro and
pegmatites. He challenged their very existence! This is a common creationist tactic --when confronted by opposing evidence, deny it! As you can see from the photo on the front cover (also Figure 6) they do indeed exist. There is no question as to their authenticity (M. Easton, Personal communication, Sept. 1987).
I explained that there were features that show conclusively the sequence of rock formation from basaltic flows, 30 kilometers to the south near Madoc, followed in a complex way by the sedimentary rocks, succeeded by the intrusion of the gabbro plutons and finally the pegmatite
intrustive bodies. In fact, I collected samples from this very sequence and sent them to him with a description. On the April 12th call, he challenged that sequence by claiming it was not a verticle one, but was over a large distance. I told him the sequence had been tilted on its side. He still did not appreciate this sequence.
I told him the nature of the intrusive rocks is very conclusive. Features include contact metamorphic recrystallization of the sedimentary rocks by the heat of the intrusive body. He claimed that the recrystallization was not due to the molten intrusive rock but, since the intrusive rocks were first, was caused by some sort of chemical alteration of the sedimentary rocks.
I explained to him that the intrusive rocks, including the pegmatites, show little or no regional
metamorphic alteration, but the surrounding sedimentary and volcanic rocks are very much cooked. Thus, the intrusive rocks must have been implaced after, or very near the end of the metamorphic event. I had to explain what regional metamorphism was (alteration of large areas by heat and pressure during mountain building). He had no answer for that.
I described to Gentry another conclusive evidence of intrusion. There are pieces of sedimentary rocks enclosed within the intrusive rocks, engulfed and surrounded by the melt. The quotes above on the Faraday Mine describe some of these features and Figure 11 is a photo of a piece of pegmatite from the dump of the Faraday Mine with an inclusion in it. I asked him how, if the sedimentary rocks were younger than the intrusive rocks, did these inclusions get into the solid rock? Gentry denied the existence of these inclusions but their occurence is described in the literature I had already sent him. In addition, these inclusions are very common and descriptions of them occur throughout the geological literature of the Shield, which Gentry either has not read or does not understand.
Above I have described some of the "proof" Gentry says does not exist. Let me summarize: 1) The samples of biotite that contain Gentry's Po halos came from
pegmatite dikes and calcite vein-dikes that cross-cut metamorphosed volcanic, sedimentary and igneous rock units --the dikes are clearly the last to form, not the first; 2) these dikes are not the vast extensive granite gneisses Gentry claims are the backbone of the mountains and continents --they are relatively small features; 3) two of the sites are not even granites but calcite vein-dikes, most likely of hydrothermal origin. The biotite was formed in the solid matrix by metamorphism; and 4) crystal size in igneous, vein and metamorphic rocks ranges from microscopic to very large, is primarily due to cooling rates and crystal growth, and cannot be used to identify "created" rocks.
Although the geology of the three sites discussed above conclusively disproves Gentry's claims of instant creation of the "primordial basement rocks", it does not explain the apparent occurence of the Po halos as described by Gentry. But this does not mean that there are no explanations. Clearly there will be a more logical and scientific explaination, perhaps including misidentification of the halos themselves due to sectioning other than through the centre of the sphere (Hastings, 1987b).
There are several lines of evidence supporting a U-rich fluid migration precipitating the Po. 1) The very fact that Gentry's halos occur in areas of unusually
high uranium minerallization and metamorphism. 2) That there are no halos for the thorium decay chain, even though the Th to U ratio is over 5:1 in the Faraday pegmatite, due to the insolubility of Th compounds (Brown, 1987). 3) No halos have been found in lunar rocks. 4) The geology of the mine sites listed above have different origins (magmatic -Faraday pegmatites- and hydrothermal -Silver Crater/Fission) suggests that the halos may be connected with a common origin. 5) The U minerallization is primarily a precipitation (mainly in mafic minerals like biotite) in a reducing environment near the contact of the wall-rock and in fractures and cleavages in the case of the Faraday pegmatite (Masson & Gordon, 1981). 6) Oxygenated fluids rich in fluorine, phosphorus, and carbon dioxide readly disolve uranium and increase the fluid's mobility (Masson & Gordon, 1981).
There is a major misconception, and not just by Gentry, about the distiction between the formation of the host mineral and the formation of the Po halos. The formation of the minerals, like biotite, is irrelevent to Po halo formation as the Po was implaced after the formation of the mineral was complete, maybe by millions of years. So it does not matter whether the biotite formed from the normal sequence of mineral formation from a magma (Faraday), or was deposited via hydrothermal, or grew in the solid matrix of the host rock due to
metamorphism (Silver Crater, Fission). The Po could have been deposited at some later time when the U-rich fluid started to flow.
The Faraday Mine pegmatites are concidered a complex unzoned type (Masson & Gordon, 1981) where the pegmatite has undergone post-magmatic alteration involving deformation, hydrothermal activity and metasomatic reactions with the wall-rock. The uranium enrichment in the pegmatites is a two-stage process of a primary magmatic concentration and a secondary, later, concentration due to fluids picking up U and Th from both the pegmatites and the wall-rocks (mostly the syenites) and precipitation.
Masson and Gordon (1981) note that there are 5 principle controls for U deposits in the Bancroft area. 1) Premetamorphic concentration of U in the sedimentary deposits of the Supergroup. 2) High-rank regional
metamorphism (the Grenville Orogeny). 3) Regional deformation of the country rocks causing fractures and openings for the emplacement of the pegmatites. 4) The proper geochemistry of the country rocks for mobalization of uranium, such as syenite and marble. 5) Large granitic bodies near by for the remelting and production of the magma, during the latter stages of regional metamorpism, for the pegmatites.
The geology of the sites in which Po halos are found clearly shows that Gentry's "proof" of instantaneous creation and a young Earth is nothing of the sort. Gentry's Po halos simply do not occur in "primordial granites", but instead were formed in relatively young dikes that demonstrably crosscut older sedimentary and igneous rocks. Gentry claims to be an objective scientist but he has, in fact, ignored the very extensive published evidence that disproves his hypothesis. In addition, when confronted with this evidence he simply denies its existence. That is not science, it is pseudoscience!
Help on this project came from many sources, and without their interest this paper would never have been written. I gratefully thank for the conversations, letters, phone replies, and visits for clarification of the geology of Ontario the following: Bob Gait of the Royal Ontario Museum in Toronto; Louis Moyd of the National Museum of Canada in Ottawa; E.B. Freeman, Ministry of Northern Development and Mines Communications Planner Mines and Minerals in Toronto; Norm Trowell, Supervising Geologist, Precambrian Division of the Ontario Geological Survey at Toronto; V.C. Papertzian and Dave Williams, Geologists, Ministry of Northern Development and Mines at Tweed; Derek York, Physics Dept., University of
Toronto; and David Pearson, Dept. of Geology, Laurentian University, Sudbury, Ontario.
Special thanks for their time for our discussions goes to Hans Meyn, Ministry of Northern Development and Mines Resident Geologist at Bancroft; Bill Grant, drill core library geologist at Bancroft; and to Mike Easton, Leader, Grenville Working Group, Precambrian Division of the Ontario Geological Survey at Toronto for our field trip to see stromatolites in the Bancroft area. Help on finding many of the references came from the staff of the Mines Library of the Ontario Geological Survey at Toronto, to whom many thanks are given.
I am also grateful for the input by correspondents John Eichelberger, Steve Dutch, Gregg Wilkerson, Ronnie Hastings, Bob Schadewald, Phil Osmon, and Frank Awbrey.
Gratitude is also given to my editor, Brent Dalrymple, for his time on revisions of this manuscript, letters and helpful suggestions.