YEC Flood Geology Revisted: Varves

Mechanical Bliss · #1 19th February 2003, 08:26 PM

A varve is "a sedimentary lamina or sequence of laminae deposited in a body of still water within one year's time; specifically a pair of layers seasonally deposited in a glacial lake. A glacial varve normally includes a lower 'summer' layer consisting of light-colored sand or silt, which grades upward into a thinner 'winter' layer, consisting of clayey, often organic, dark sediment" (Bates & Jackson, eds.)

Using the basic uniformitarian principle that "the present is the key to the past" we can observe these annual accumulations of laminae in modern day lakes and compare them to older varves to discover how they were formed. By this observation, geologists have concluded that formations such as the Green River varves, in some places, represent approximately 20 million years of time. Clearly this is not possible with a Young-Earth scenario.

There are numerous issues with flood geology, however, such as secondary sedimentary structures (raindrops, mudcracks, etc.), fossilized flora and fauna, seafloor spreading, thrust faulting, the formation of mountains, etc. In light of geologic evidence for varves (or one could pick any of the other problems with flood geology) how can one viably cling to such a nonsensical notion of a Young Earth or a global flood without simply disregarding and ignoring reality?

lucaspa · #2 19th February 2003, 10:55 PM

Varves are a subset of "rhythmites" -- deposits that occur in cycles. Varves are annual or semiannual. Other rhythmites can have time frames that vary.

As you noted, varves falsify Flood geology. Again. There is no way a single, year long Flood (especially a violent one) could lay down 20 million layers in a single sediment. Particularly when deposits close by have none.

The uniformitarian principle can be checked independent of uniformitarianism by examining the individual layers and testing how they were laid down. So saying varves represent annual cycles is not dependent on uniformitarianism, even the correct form you used.

Mechanical Bliss · #3 20th February 2003, 12:21 AM

True that the argument is not dependent on uniformitarianism. I just thought it would be another point to throw in there.

Gracchus · #4 21st February 2003, 09:18 PM

Any mention of varves and unconformities seems to scare off YEC's.

lucaspa · #5 21st February 2003, 09:25 PM

19th February 2003 at 11:21 PM Mechanical Bliss said this in Post #3

True that the argument is not dependent on uniformitarianism. I just thought it would be another point to throw in there.

I was just afraid that someone reading it might misunderstand and think that the varves were dependent on an "assumption" of uniformitarianism and didn't want that to happen and spoil your excellent point.

ardipithecus · #6 22nd February 2003, 02:32 AM

One might mention that many varves are of fine materials that take a long time to settle.

Gracchus · #7 22nd February 2003, 08:35 PM

...and still no creationists respond.

Micaiah · #8 23rd February 2003, 10:42 AM

Okay, lets consider the Green River valves. You assert that these are the result of uniform geological processes over about 20 million years in some places.
1. I would like some further explanation in layman / semitechnical language on your theory and the evidence you claim supports the theory.

- Provide a detailed explanation of how these varves are formed.
- Provide a detailed description of the varves in question. Are they completely uniform throughout the depth of layers, and throughout the entire Green River area. Describe the type of material in question.
- How many laminae were formed in one year? How many are formed in one year in contemporary times?
- How thick were the laminae?
- How do you know for sure that the rate of laminae formation was constant over the 20 million years?
- Does the fossil evidence support your assertion?

2. Provide your sources of information to support your suggestion. Who are the geologists that promote your claim?

3. What are the implications of demonstrating that these layers could have been formed within the timeframe of Scripture.

edgeo · #9 23rd February 2003, 12:07 PM

Today at 07:42 AM Micaiah said this in Post #8

Okay, lets consider the Green River valves. You assert that these are the result of uniform geological processes over about 20 million years in some places.
1. I would like some further explanation in layman / semitechnical language on your theory and the evidence you claim supports the theory.

- Provide a detailed explanation of how these varves are formed.

True varves form due to seasonal fluctuations in biological activity and clastic sediment availability in standing bodies of water. 

- Provide a detailed description of the varves in question. Are they completely uniform throughout the depth of layers, and throughout the entire Green River area. Describe the type of material in question.

I am not convinced that the Green River varves are true varves, though I am willing to admit that, in certain locations, they could be.  Some varved sequences are quite uniform, but I'm not sure what the relevance of this is.  And no, varves are clearly not found throughout the entire Green River basin.

- How many laminae were formed in one year? How many are formed in one year in contemporary times?

Typically one dark lamination and one light lam.  Sometimes this varies and sometimes the sequence is disrupted by storms, etc.  However, counting varves by competent researchers can be reliable within small limits of error.

- How thick were the laminae?

Not sure, but probably on the order of a mm.

- How do you know for sure that the rate of laminae formation was constant over the 20 million years?

How do we know anything "for sure?"  All methods are simply evaluations.  However, by  comparing with modern environments and rates of deposition, we can be quite certain about the interpretation of varves.

- Does the fossil evidence support your assertion?

In general, yes.  I am not familiar with much of the Green River fossil assemblage.

2. Provide your sources of information to support your suggestion. Who are the geologists that promote your claim?

This is a bit of a fishing expedition for you, isn't it?  The methodology of varve counting is several decades old.  There are numerous references and experts.  I suggest you get a good geology text or just do a websearch.

3. What are the implications of demonstrating that these layers could have been formed within the timeframe of Scripture.

Varved sequences cannot be interpreted as forming within scriptural time frames.  There is no mechanism for the formation of hundreds of varves per year, or under turbulent conditions of a biblical flood event.  At the same time, we can see them forming today in the normal fashion.  The rational conclusion is that the varve counts are approximately correct.

Mechanical Bliss · #10 23rd February 2003, 12:30 PM

Today at 09:42 AM Micaiah said this in Post #8
- Provide a detailed explanation of how these varves are formed.

Varves form in shallow, stillwater lakes where darker, organic-rich laminae are interbedded with lighter silt, clay and carbonates. The Green River varves also show evidence of freshwater evaporites such as trona (Na3CO3HCO3*2(H20)) and Halite (NaCl) in some members of the formation totaling 50 m in thickness covering an area of several square kilometers. Evaporite formation is not a rapid process either.

The warmer, summer temperatures promote growth of algae/plankton that die as the termperature cools. They sink to the bottom of the lake producing the darker bands (winter bands). In the warmer months, this allows precipitation of dissolved ions in the lake giving rise to the lighter bands (summer bands).

- Provide a detailed description of the varves in question. Are they completely uniform throughout the depth of layers, and throughout the entire Green River area. Describe the type of material in question.

The material in question is variable and is relatively uniform throughout the area, but as expected, certain units are thicker toward what would be the middle of the lake and thinner toward the margin. There are several basins to this ancient lake, so there are several areas of thickening and thinning.

The rocks include shales, oil-producing shales, fine sand, precipitated freshwater carbonate, and halite.

- How many laminae were formed in one year? How many are formed in one year in contemporary times?

I already answered these questions in the first post.

Two laminae are formed yearly according to the warming and cooling cycle above. We also see variations according to Milankovitch Cycles (the eccentricity of the Earth's axis causes localized warming and cooling periods due to the Earth's changing position) and sunspot cycles, for example. We can see this process occur today.

- How thick were the laminae?

Highly variable. On average, roughly 0.1-1mm thick and sometimes up to a centimeter from what I can tell.

- How do you know for sure that the rate of laminae formation was constant over the 20 million years?

We can look at the composition of the laminae to determine how they form. We know how carbonates form in freshwater by precipitation and runoff from streams deposits sediments in lakes in hotter summer temperatures, and we can determine the composition of the organic layers.

We can also use radiometric dating of volcanic tuffs enclosing an interval of varve formation. We can use that time interval to compare with the number of varves and we get a very close and reasonable expectation for the prediction.

- Does the fossil evidence support your assertion?

Yes. We find fossils of freshwater fish, frogs, and birds (some of which are now extinct) preserved by deposition of silt on top of them as they fell to the bottom where the relatively deeper layers of the lake would have low oxygen, no free oxygen, and chemicals condusive to preservation (such as hydrogen sulfide).

2. Provide your sources of information to support your suggestion. Who are the geologists that promote your claim?

It would be silly to simply list the authors of every sedimentary geology textbook on my bookshelf that discusses varves (and the Green River in particular) and silly to list every single author of every single paper on varve formations, and even specifically those on the Green River varves. In effect, mainstream geology accepts this interpretation. You can freely search for yourself to see this.

3. What are the implications of demonstrating that these layers could have been formed within the timeframe of Scripture.

There are no implications because this cannot be demonstrated. You also have to somehow falsify what we know about varves and why we would see freshwater evaporites at all.

Volcanic ash deposition is not the same as varve formation. Turbidites are not the same as freshwater varves. I can only think of so many examples you might bring up that are not analogous to this situation.