Ken Van Dellen

Thanks, John. I thought you sounded like an impatient guy who wanted everything to happen rapidly - reef growth, evaporite precipitation, plate movement, mountain growth, and my responses. :)

I apologize for not being clearer. When I said Silurian patch reefs in Michigan "may be" 140 meters tall, I was not expressing uncertainty at all. Their dimensions are well known, having been measured in drill cores and by remote sensing, such as seismic logs. Perhaps it would have been clearer had I said "as much as" 140 meters tall. I'm trying to give you facts to consider, and am trying to avoid "perhaps", "might have", "could have", and "may have", which I see sprinkled throughout your posts. I'm not at all uncertain. Are you? Your comment about reef growth, "At...approx one-half metre per year, it might have taken about 300 years to form", is a case in point. You can plug in any number you want, realistic or not, and get the result you want, but that doesn't prove or disprove anythiing. You need to consider all of the data.

I evidently confused you when I introduced post-glacial rebound in connection with mountain growth. Both involve isostatic uplift as a result of unloading, but the former is demonstrated in post-glacial shorelines of the ancestral Great Lakes in the Great Lakes states, notably Michigan, while the latter is demonstrated in mountainous regions. Yes, this takes careful measurement because it is so SLOW, but it is measurable.

Your material on the growth of the Andes is confusing to me because it is unclear what is a quotation and what is your commentary. However, I would suggest that you look at the numbers.Words like "slow", "gradually", "fast", and "suddenly" are relative terms. Consider a "growth spurt" in a teenager. So the Andes may have had a growth spurt, and geologists have discovered something we didn't know before. This doesn't significantly change the plate tectonics model, and is a much more complicated situation than reef growth or evaporite deposition.

In answer to your final question, let me ask how much sea water would have to evaporate in order to precipitate the amount of salt in the Salina Group in Michigan. Of course, you could speculate on temperature, wind, salinity of sea water at that time, etc., and some assumptions would have to be made, but might they not be reasonable assumptions? Or should we say, "It might have been really hot or really windy or the sea had a really high salinity"?

Remember that the subsidence of the Michigan Basin, the growth of the fringing patch reefs, and the deposition of the salt and gypsum during this time, however long it all took, are just a small part of the geologic history of Michigan (as an example of Earth history). The deepest crustal rocks in Michigan are granites and metamorphic rocks, the kinds of rocks that we find in the depths of mountain belts, and the surface of this basement rock is rather flat, which suggests that there were mountains here at one time, and those mountains were eroded away. Running in a curve, from Oklahoma to western Lake Superior, where it passes between Isle Royale and the Keweenaw Peninsula, and down through the Lower Peninsula in sort of an L-shape, is a rift valley, like the one in East Africa, splitting those ancient mountain roots. (The copper-bearing basalt beds and conglomerates, thousands of feet thick, of Isle Royale and the Keweenaw are a stretch of this rift valley that is at the surface, rather than buried under later sedimentary rock.) On top of the basement is sedimentary rock, 14,000 feet thick in the central part of the Basin, much of it deposited during subsidence, and most of it marine. It contains the record of a succession of life, and indicates various depositional environments. It tells of transgressing and regressing seas in the continental interior, while the continental margins were flood more continuously, but not always. Layers nearer the surface have coal beds and plant fossils in rocks indicative of coastal flood plains and stream channels. On top of it all, in most places, are the glacial deposits, with moraines, drumlins, and other landforms, including old shorelines that curve upward from south to north, recording the post-glacial uplift. Yes, we can wonder about how long it could take for some salt to precipitate, but there's a lot more than we need to consider. More than I have time and space to discuss here. 

It's exciting to study the creation and see what God has done. He has done more than most people imagine.

John, I have an entire shelf of books by Christians on the issue of origins, and covering the entire spectrum of views from young-Earth creationism to evolutionary creation, and many of them misquote or quote out of context what scientists have written, distort or misrepresent the data (either deliberately or unwittingly), and show vast ignorance of the subject. Judging from the reviews of these two books on Amazon, they are probably more of the same. Usually the more "orthodox" such books are, the worse the science is. Some Christian writers even simply recycle material gleaned from other writers, and use "mined quotes" from books that have lifted quotes out of context. Often authors have minimal education in the field they write about, such as engineers writing on geology, paleontology, etc. This is embarrassing to many Christian scientists.

On the subject of radiometric dating, many are "expert" on the subject who have never done anything with it. Suppose that you were manufacturing something, and you occasionally sent a sample to a lab to be analyzed for quality control. Would you do that if you knew ahead of time that the lab technique was unreliable and the results worthless? You wouldn't waste your money. Yet, you recommend an author who claims that geolgists are doing exactly that, paying for results that they know are worthless. Just as geologists, paleontologists, archeologists, and others, have uncovered the Piltdown hoax, the Nebraska man hoax, the dinosaur man-track hoax, and others, they would certainly, by now, have exposed the radiometric dating hoax. However, geologists use radiometric dating, and they have ways to check, using alternative isotopes, to verify that results are reasonable. (I won't say "accurate", because even you state your age, knowing your date of birth, you are accurate only within a certain range, +/- a year and not down to the second or...)

Incidentally, I know the former manager of a large lab that does radiometric dating, who was asked by a geologist affiliated with the Institute for Creation Research to date a recent basalt sample from Hawaii. The manager pointed out what this geologist probably already knew, that relatively young volcanic samples give very old radiometric dates by the K-40/Ar-40 method, because a lot of non-radiogenic argon in the magma is trapped in the resulting volcanic rock, noting that it is not their practice to date such material. He was told to go ahead and do the dating, and the lab was paid for the work. The ridiculous result has since been published as an example of the unreliability of radiometric dating.

A good article on radiometric dating written by a Christian is at http://www.asa3.org/ASA/resources/wiens.html. I know there are Christian websites that disagree with this article, but if we look at the whole story, the radiometric dates make sense. (See my outline of Michigan geology, above.) If you want to use Genesis 1 as a rebuttal, consider when Earth was created - not in the seven days listed there. Theologian John Walton, in his book The Lost World of Genesis One, Intervarsity Press, makes the case that Genesis one is talking about the dedication of an existing creation. It's worth reading, even if you disagree, to get a different perspective on this subject.

Since you seem interested in geology, let me recommend "The Bible, Rocks and Time" by Davis Young and Ralph Stearley, published by Intervarsity Press. The authors are two Christian geologists writing about geology. (Note: They are not writing out of their field. Both have done research in geology, as well as teaching the subject.) The book presents facts and data about God's world, and explains how geologists interpret the data, while discussing how they, as Christians, integrate this with their faith. It's a little technical, but they explain things well, and I think you will understand it quite well.