Oolon Colluphid

It occurred to me today, as these things do, that stalagmites and -tites grow at a definable rate, do they not? Probably (pick me up here if not, John, Patrick et al) each drop adds a microscopically identifiable layer of calcium carbonate (or whatever). Either way, they ought to be datable, if not with tree-ring accuracy, surely something along those lines.

Therefore, if we find stalagmites older than 6,000 years, the earth must be older than that, yeah?

What’s more, they’re in caves usually. Would not caves be filled up with silt during the Flood? Therefore, in places such as Cheddar Gorge in Somerset, where there is a large (presumed) river valley ie one cut by the flood waters, how can there be caves in the valley sides, unsilted, and with ancient stalagtites? This must at least push the date of the Flood well outside any biblically-based date.

Only just thought of this, so feel free to pick it apart.

Oolon

Pandora

Here's a report on dating of speleothems from the Middle or Lower Pleistocene period.
<a href="http://www.uib.no/People/nglbn/scari.pdf" target="_blank">http://www.uib.no/People/nglbn/scari.pdf</a>

I was taught that speleothems required air in order to form. those present in underwater caves are previously formed and will not grow any further. (ie. When caving, do not damage as they can't repair themselves.) The rate of formation is governed by the rate of rainfall, overlying soil structure and the composition of the rock. If you consider the speed of rainfall of the Flood, the caves formed would have been underwater too quickly to allow for any spectacular speleothem formation. (I may well be wrong on this.)

However here's a response by the cretinists.
<a href="http://www.answersingenesis.org/home/area/magazines/tj/v12n3_caves.asp" target="_blank">http://www.answersingenesis.org/home/area/magazines/tj/v12n3_caves.asp</a>

Kevin Dorner

When randman was told in no uncertain terms to pick one of AnswersInGenesis's "best arguments" one of them was <a href="http://www.answersingenesis.org/home/area/magazines/tj/v12n3_caves.asp" target="_blank">that cave article</a> and, needless to say <a href="http://iidb.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=58&t=000370&p=2" target="_blank">Patrick rather completely shredded it.</a>

Not having access to much scientific literature, I couldn't do many lookups, but two avenues would be studies into the rates of speleothem formation and the fact that some speleothems exhibit annual banding as trees do, due to variation in the mineral content of the drip water from things like runoff and rainy seasons. (There are caves in Uganda like this I think...)

[ March 22, 2002: Message edited by: Kevin Dorner ]</p>

Coragyps

Quite a bit of "tree ring" as well as isotope dating (uranium-lead, as I remember) has been done in the Carlsbad/Lechungilla cave system a couple of hundred miles west of me. And one of the major "paleothermometers" for North America is the stalactites in a cave in Nevada - I can't think of its name - that has been cross-correlated with Greenland ice cores, etc. and dated very precisely.
And yeah, if you have ever been inside Carlsbad, it will stretch your credulity to think that it could have formed in 6000 years.

John Solum

Hi Oolon,

I've never heard of being able to date stalmites/tites by counting the number of laminae, and I'd imagine that the rate at which those laminae are added is variable. There is a way to radiometrically date calcite (the mineral that the cave formations are made of) if it's not older than ~300-500,000 years. The technique is called uranium series disequilibrium dating (this is the technique that Coragyps is referring to and the one that's discussed in the paper Pandora linked to). U-series disequilibrium dating is based on the fact that it takes time for the steps in the decay of U-238 to U-234 to reach secular equilibrium (when the activity of U-238 and the activity of U-234 are the same). It takes about 1 million years (IIRC) for this to occur (once equilibrium is reachedthis technique can't be used, and there are, of course, limits due to the sensitivity of instruments), and the greater the disequilibrium (the greater the difference between the activities of U-238 and U-234) the younger the sample is. That's the sum total of my knowledge about U-series disequilibrium dating.


Here's the paper about the cave in Nevada that Coragyps referred to (incidentally Kolesar is the guy who taught my undergrad geochemistry class, this paper was one of the things we went over):

Winograd, Isaac J; Coplen, T B; Landwehr, Jurate M; Riggs, A C; Ludwig, Kenneth R; Szabo, Barney J; Kolesar, P T; Revesz, K M. Continuous 500,000-year climate record from vein calcite in Devils Hole, Nevada.Science, vol.258, no.5080, pp.255-260, 09 Oct 1992

If you combine U-series disequilibrium dates with carbon and oxygen isotopes you can get a really nice record of climate changes.

John