Earth science curriculum tailored to fit wavering fundamentalists

I'm not sure what would be intrinsically wrong with assumptions. Do you, or does anyone in your audience go though life without making assumptions?Clearly, some assumptions are valid and others not. What your skeptical 'audience' needs to do is show that the assumptions are not valid if they wish to proceed with the argument. The point here is that uniformitarianism, in its present form (which we term 'actualism') has not been shown to be invalid for the explanation of natural features.Now, if someone wants to be hyperskeptical, that's their problem. I recommend that they not board an airliner for travel purposes. There is a bit of a misunderstanding here. Floods do their sorting (if it really happens) of species in space. Evolution sorts species through time.This notion on your part suggests to me that you still retain the YEC understanding that there is one geological event in the history of the earth, and everything really happened at once.Frankly, it appears to me that you are not being completely honest here. Uniformitarianism is more than just an assumption. It is a principle that is used to interpret natural phenomena. It has survived since the days of Hutton, though our understanding of what is normal has changed. In our modern usage, it does not exclude catastrophic events such as meteorite impacts, etc.YECs would have us believe that the biblical flood refutes uniformitarianism. However, there has never been any evidence to support such an event. Consequently, the only people who deny uniformiatrianism do so for biblical (i.e. religious) reasons, not scientific ones. Basically, this requires a belief in such ideas as C-decay or alternate states, or magic (that would be supernatural intervention). All of these, of course, leave no evidence behind.Really, if you want to refute a geological principle, you need to show that it is scientifically invalid. Ponder harder. Edited by edge, : No reason given.

If an all-powerful god actually acted upon that power, science wouldn't work.

Not sure what your question is. The chart shows a peak 14C level in 1963 which was the year of the Limited Test Ban Treaty was signed, ending atmospheric tests for US, UK and the USSR. The level has been declining ever since. This is what we would expect.China's last atmospheric test was in 1980.I don't know of anyone age-dating objects less than a hundred year old.It seems you might be confusing two time ranges here.ETA: I see that the chart shows declining 14C as the NCSE article states. I also see that the rate of production is still higher than an equilibrium state. That is because the production, while high, is declining eventually back to natural levels.So, the NCSE article is correct. Nulear testing temporarily raised the production level and the amount of 14C in the atmosphere. We are now going back to equilibrium. It is just taking a while. Edited by edge, : No reason given.Edited by edge, : No reason given.

Right, it is confusing. I think Weber discusses variation of the natural 14C, but that is not what the chart emphasizes (particularly since it only goes back to 1955).

Wow, this is another one of those YEC-type explanations that we used to say, 'doesn't approach the level of being wrong'.Before anything else, I will admit that I have not researched nor read all of your references, but after reading the abstract by Hovland, I have a few observations right of the top of my head.My first questions are about the size and shape of the salt deposits:Hovland mentions the GOM salt deposits, which primarily refers to the Luann Salt which, curiously, has a source confined to the Jurassic System in the Gulf area. To me this is kind of weird. To have a regional alteration pattern confined to one age and one rock type that forms a nice, tabular deposit, parallel to stratigraphy, just stretches the imagination. For reference, this map shows how large that deposit is. If you look at the size of this deposit, one wonders exactly where is the intrusion that caused so much seawater to boil (which it won't do, by the way, due to hydrostatic water pressure). It's got to be huge, and yet there is no evidence of it; not even a gravity anomaly or a remnant thermal anomaly.Another argument is with regard to the Red Sea. We see plenty of salt deposits forming in the evaporative way in the adjacent Afar region (an almost identical and continuous geological setting), so why does Hovland have to reach for a magmatic-replacement origin for the salt?And where are the salt deposits at the modern mid-ocean ridges? Sure, the rocks are enriched in sodium, but never do we see huge salt deposits...Neither do I see any chemical formulas showing the reactions to form such a replacement of sedimentary minerals by salt. Nor do I see an explanation for the purity of the salt beds. The author should be able to show us some replacement textures, even if they are synthetic, to provide some evidence that this could happen.What was the protolith (original rock type) of the 'replaced' bed?What is the composition of the intrusion?Maybe all of this information is reported somewhere in the sources that you cite, but my guess is that they are not. As you note the paucity of information on this subject suggests that it is a red herring. I have no idea (well, maybe one...) why anyone would postulate such an origin of regional salt beds based on such flimsy arguments.

.
Well, I'm getting some conflicting ideas here between the website and the abstract, so I'm going to shut up until I read more and if the discussion goes any further.Just let me say that deposits such as the Afar (modern) and the Green River Basin (ancient), the Luann Salt (ancient) and the Great Salt Lake Basin (modern) do not look like they could be formed in the way that Hovland seems to suggest. But then I'm not sure what he's saying yet, since he also mentions sabkhas, which are a different animal entirely.ETA: And yes, I'm sure that Heerma is using Hovland's work to support the old argument that salt deposits can form in other ways than by evaporation. But he leaves out this statement by Hoveland: Just a moment...The idea is to show that 'evaporites' can form in 'flood' conditions. My counter is that we have a perfectly good explanation that accounts for the actual features of the known deposits and the Hoveland model (which may have some application) is not adequate to explain all deposits. Edited by edge, : Amplify on the arguments

The layering is certainly sedimentary in origin.Now, if one were on the hard-core hydrothermal-replacement bandwagon, one could say that the replacement is so detailed, so precise and so faithful to layering, is a perfect replication of the original sedimentary texture.Over large distances (regional scale), I would say that's never been seen before.Is it recrystallized? Sure, that's the nature of salt deposits. But to present no other metamorphic textures tells us that it is not thermal in origin. Radiometrically, no, unless there are volcanic ash layers that could be dated. They could, however, be dated by index fossils, such as pollen grains. Edited by edge, : No reason given.

Absolutely. Even at 800 degrees C, there should be some kind of zonation of thermal metamorphism, especially considering the size of the system we are discussing. Those temperatures are the equivalent of the final solidification of a granitic magma. These things are pretty well-recognizable by mineralogists. Basaltic magmas (which we would expect in a rifting environment such as the Red Sea) would involve even higher temperatures (up to 1100 C) which would have an even more intense thermal aureole.The whole thing just doesn't make much sense, except in some very narrow applications and even then, I've never seen anything like what Hovland is describing.ETA: His schematic diagram of fluid flows is unlike any that I have ever seen before; and again, it doesn't look realistic.I would still like to see the chemical reactions that would lead to salt precipitating (I seriously doubt actual replacement) in a hydrothermal environment. Edited by edge, : No reason given.

If our experience here is any indication, the task is insurmountable. In 99.9% of cases, religious belief trumps scientific evidence and reasoned interpretation.

Just for curiosity's sake, the machine in the picture is a scaling machine. It is used to scrape and bring down slabs of salt in the roof of the opening. You can see some of the scraping marks in the 'back' ('roof' in mining jargon) where it has already been used in this picture. This is primarily for safety reasons. In many mines, of all types, this is often done by hand; but, as you can see the back is quite high in this mine.

These are the Michigan Basin salt deposits with which I have actually done test work on. They are true evaporite deposits. I think the changes you are discussing are at a larger scale in the Zechstein Salt. As you can see these beds are almost pure salt and the muds or clays are simply contamination.The zonation that you refer to is excellent evidence for evaporative origin of the salt deposits that no one here has discussed previously. In a lacustrine environment it is possible to predict the order and distribution of salt minerals. Edited by edge, : No reason given.Edited by edge, : No reason given.

It would not. Just look at the flow directions. In the Hovland model the continuity is vertical and would result in a vertical zonation along structural pathways. In the evaporative model the continuity is lateral with zonation being in lateral directions controlled by stratigraphic processes.

True enough. I'm afraid I get pretty cynical participating in discussions like we have around here sometimes.

Well, they are almost all impure to some degree. However, the part that is mined is as pure as possible. The samples I've dealt with are light grayish brown with very large crystals up to several mm in dimension. That size would be very difficult if there were a lot of impurities such as clays, etc. If you look at the salt flats in Utah, the salt is almost pure halite, so they look almost pure white, even from space. Go to the Morton Salt website if you want to see some pictures of those facilities. The impurities there are mostly wind-blown silt and pollen, etc. But if it goes on the table, it's got to be clean.If you look at the underground picture on earlier pages, I'm pretty sure that the roof (or 'back') is more of a siltstone, otherwise it wouldn't have the tensile strength to stand up. Pure salt is quite weak, especially in the coarser grained variety and it will crumble, or it will flow if confined.A lot of these features of salt are what make it so economically attractive. If you have a good salt mine in the northern states, just line up the trucks and start counting your money.

It is absolutely possible, and usually easy, to tell subaqueous volcanic deposits from subaerial deposits. There are all kinds of variations depending on the type of volcanic eruption, its composition and the depositional environment.ETA: Oh, yeah, and whatever happened afterward. Edited by edge, : No reason given.