Varves

EARL DETRA

In lakes today there are many evidences of a thriving ecological system:
decayed fish bones at the bottom of the lake, snail shells, worm trails,
plant roots, and so on.

In some lakes today, yes. Not all. Are you familiar with saline lakes?


If the Green River formation really dried up
repeatedly (evaporates were claimed to exist there) ...

Claimed to exist? Surely, David, you are kidding here. Perhaps you have a better origin for bedded salt and trona deposits with syneresis cracks...


...then it should have
at times been shallow enough to have such an ecosystem.

Possibly. But is depth the only factor here?


I wondered if
these evidences have been found, and if not, why not? I realize that
there are some fossils found in this formation (even if not in the
refereed literature) but is the number and distribution of the remains
found consistent with lakes today?

Some of them, yes. Visit some of the brackish water lakes in the desert west or in other dry mountain basins. They are pretty good analogs for the geological record.


Also, well preserved fossils would
not be found in the bottom of current lakes, depositing only a small
amount of sediment per year.

I'm not clear on why you can't have fossils being deposited on the bottoms of modern lakes. This disagrees with your first sentence of this post. Please explain what happens to shell fragments and plant roots, etc. Don't we find lots of pollen, diatoms etc. in the cores from the bottoms of modern lakes? Don't we find lots of organic material?

 

DAVID PLAISTED

Many well-preserved fossils have been found in the Green River formation.
This is not just shells but entire fish and other organisms (even a bat)
with skeletons and often almost all the soft flesh. For some web pages
documenting such fossils see
http://www.ucmp.berkeley.edu/tertiary/eoc/greenriver.html

http://www.ucmp.berkeley.edu/tertiary/eoc/greenverts.html

http://www.fossilz.com/


et cetera. I also recall seeing pictures of such fossils in books and
maybe even the fossils themselves in museums. Among the fossils found
are the "gar," a large fish. Today the size ranges from 2-3 feet for
some species up to 10 feet for others, and it is primarily a fresh
water fish. The one shown in the GR formation is very well preserved.

Earl suggests that when the GR lake evaporated it became very salty and
so there was not a rich ecosystem. How could this happen unless the
lake had no outlet, and then it would have been salty indeed for millions
of years. Wouldn't we have seen a lot of crusty salt as in the Dead
Sea and then how could all of these life forms (including fresh water
gar) live there?

I'm also curious to know how such large fossils can be preserved with
such a slow rate of deposition of sediment, just one or a few varves
(or laminae) per year.

Dave Plaisted

 

EARL DETRA

Earl suggests that when the GR lake evaporated it became very salty and
so there was not a rich ecosystem. How could this happen unless the
lake had no outlet, and then it would have been salty indeed for millions
of years.

Not a problem. In fact some intermontane lakes are both saline and fresh... at the same time. Check out the information on Lake Balkash in Kazakhstan. North end fresh, south end saline. By the way, the lake that the GR Formation was deposited in is so well documented that it has a name: Lake Gosiute.


Wouldn't we have seen a lot of crusty salt as in the Dead
Sea and then how could all of these life forms (including fresh water
gar) live there?

Well, it's not a crust any more. There are extensive beds of trona and salt. At least 40 of them over a meter in thickness. And they are not everywhere only in a certain part of the stratigraphy.


I'm also curious to know how such large fossils can be preserved with
such a slow rate of deposition of sediment, just one or a few varves
(or laminae) per year.

Several ways. First of all anoxic waters have been known to preserve organics for a long, long time. Look at the first millenium boats in the bottom of the Black Sea. Even wood is preserved. Second, I expect that the carcasses settled into the mud rather than just laying on top. Third there would be little scavenging in a hostile chemical environment. And lastly, even if the material decayed there would be some organic sludge of different composition from the surrounding sediments. Voila... fossils.

 

DAVID PLAISTED

So Earl is suggesting that Lake Gosiute is partly salty and partly fresh,
partly deep and partly shallow, partly hot and partly cold. That sounds
like one mixed-up lake to me.
Dave Plaisted

 

THE BARBARIAN

A mixed up lake? No, the lake is not mixed up. Most lakes have shallow and
deep parts, and there is a definite cline between warm and cold layers.
This is quite normal, as anyone who's done even shallow diving in lakes
knows.
I'm no expert in limnology, but there's a lot to learn. One thing you might
do is check out the LANDSAT pictures, many of which can show you how mixing
(and not mixing) occurs in lakes. Surprisingly, even relatively small
amounts of water can retain these clines. Take a small rectangular glass
pan, like a pyrex bread pan. Pour in a small amount of room temperature
water to about 1/3 of the pan. Then gently pour in a small amount of ice
water tinted blue. Then gently pour in a small amount of hot water tinted
red. It helps if you do this at the opposite edges of the pan. You should
see a band of red water above a band of clear water, above a band of blue
water. This will persist for a considerable time.

_________________________________________________________________

 

EARL DETRA

You really have to get out of the rut that only radiometric half-lives change with time. Lake Gosiute was in existence for an awfully long time. There are thousands of feet of sediments attributed to this one body of water. It probably dried about 40 times as evidenced by bedded salt and trona. There are several different sedimentary facies present in the basin, some indicating fresh water some salt... all very similar to observed lakes in modern enclosed basins. And yes, some are "hot" and cold at different times and depths. These things are documented in modern lakes.

[ March 05, 2002, 11:54 AM: Message edited by: Administrator ]

 

DAVID PLAISTED

Here are some creationary web articles about varves:

http://www.creationinthecrossfire.com/documents/Varves/VarvesProblems.htm

(note that there has been controversy about them in the literature)

http://www.answersingenesis.org/Docs/213.asp

(note that fossils do not form even in oxygen poor conditions in water)

http://www.answersingenesis.org/home/area/feedback/negative2feb2001.asp

(note that alkali do not help preserve fossils either -- also note the
smoothness of the varves showing that they were laid down rapidly
because there was no time for erosion or other perturbation in
between)

Someone suggested the fish sank in the mud and were fossilized -- if
so this would have disturbed many varves above and around the fish
fossil and this disturbance would be evident. My impression is that
this is not so.

Dave Plaisted

(Also the preservation of wood in the Black Sea is not relevant since
cellulose is likely to preserve more than the soft parts of living
organisms. I'd be curious to know if there is any lake today in which
such large fossils including soft flesh are forming and this lake lays
down such thin varves with no evidence of disturbance.)

(I also found a quote from the literature that says that the salt
deposits in the Green River formation are not evaporates -- will try
to track it down -- this calls into question the lake drying up many
times.)

* * *

from a second email

Here is the quote about evaporates in the Green River formation:

Sozansky, V. I., "Depositional Environment of the Green River Formation of Wyoming: Discussion," Bulletin, Geological Society of America, vol. 85 (July 1974), p. 1191. Sozansky is at the Institute of Geological Sciences of the Academy of Sciences of the Ukrainian S.S.R., Kiev.

"These data contradict the evaporitic hypothesis and need a new explanation. Precipitation of salt from highly mineralized thermal brines of juvenile origin that escaped from the mantle along deep faults is the most logical explanation for the origin of salt deposits. Because halite and trona are genetically related, I believe that trona is also of juvenile origin."

 

EARL DETRA

David says:
Here are some creationary web articles about varves:
http://www.creationinthecrossfire.com/documents/Varves/VarvesProblems.htm

(note that there has been controversy about them in the literature)

And controversy means what? I think the controversy here is dreamt up by creationist drawing from several resources and making various misapplications of geological thought.

This reference is kind of funny, actually. Personally, I was not aware of true varves in the Green River Formation. And it appears that neither Kurt Howard nor any of the references he cites are either. I see several references to "varve-like" laminae and "varves" in quotes indicating that they are perhaps not varves. And yet Howard proceeds as though evolutionists agree that they are indeed varves and continues to shoot the idea down. This is a classic strawman argument. Howard appears very confused when he discusses ash flow laminae at Mount Saint Helens, calling them "varve-like," and comparing them to actual varves. This is absolutely silly. There is no resemblance between varved sediments and ash flows to a trained geologist. He compounds the error by speculating that geologists cannot tell the difference between turbidites and varves. This is practically in insult. Howard needs to establish that indeed these laminae are what the mainstream scientific community calls varves before he can attack the validity of varves in the Green River Formation. It appears that he is conflating varves and laminae. So sorry, but they are not the same.

I am also interested in the transformation from varves to shale laminae where Howard talks about the bedding between the ash units. There is either major deception here or the author really does not understand varves or sedimentation. I am sorry but this reference is not credible.

I will move on to your other references perhaps tomorrow. I hope they are more compelling.

Best Regards,
Earl

 

HELEN

I had the opportunity to have lunch with Dr. Elaine Kennedy, geologist
at GRI, last week, and I asked her about varves. In essence she said
that although varves were known to have the dark and light alternating
bands, other depositions could do this as well and that the distinctions
between varves, rhythmites, and any forms of layering becomes quite, if
you will exuse the expression, muddy. Different explanations trade
places regarding different areas depending on different ideas and
discoveries. In short, there is almost no exact way to look at any
series of thin layers and say "these are varves." There are ways to
say, with pretty good certainty, that certain depositional series are
NOT varves, but there is no way to definitely define varves so as to
exclude any other possibilities.

As for the Green River formations, the current thinking among many
geologists is that they are definitely NOT varves. There are too many
evidences going against them, including multistrata (or polystrate)
fossils, differing numbers of varves per unit area in different
sections, and the impossibility of that many years of uninterupted
layering.

Thus, while varves do exist, certainly, they cannot always be defined as
clearly as some here would like them to be. She also mentioned that those
geologists who said they could, know better.

 

EARL DETRA

David, with respect to your second link, here are a few comments.

Garner: The reason is that the deposit is said to consist of several million thin layers of shale, each of which is said to represent a single season’s deposition in an ancient lake (the coarser layers in the summer, and the finer layers in the winter).

Okay, this is wrong. Garner does not give a complete or accurate description of varves. The layers in varved sediments are compositionally different. They do not require a change in grain size.

Garner goes on to quote old-earth geologist Dr. Davis Young:

‘There are more than a million vertically superimposed varve pairs in some parts of the Green River Formation. These varve deposits are almost certainly fossil lake-bottom sediments. If so, each pair of sediment layers represents an annual deposit . . . . The total number of varve pairs indicates that the lakes existed for a few million years.’

Now, David, you will note that Young says there are varve pairs in some parts of the Green River Formation. Not everywhere. This will be especially important where Garner explains that there are more shale layers between ash horizons in different parts of the basin.

Garner: Experiments by scientists from the Chicago Natural History Museum have shown that fish carcasses lowered on to the muddy bottom of a marsh decay quite rapidly, even in oxygen-poor conditions. In these experiments, fish were placed in wire cages to protect them from scavengers, yet after only six-and-a-half days all the flesh had decayed and even the bones had become disconnected.

This is interesting. I have a feeling that Garner does not give us the whole story regarding these experiments. For instance does the fact that organic material has decayed mean that no fossil could be formed? You will notice that the quote says the bones had become disarticulated. Does that mean that there were still bones present? Obviously! Now, what are the fossils in the Green River Formation composed of? Could it be that the abundant fossils are composed of replaced bone structures?

Garner quotes: ‘Enormous concentrations’ of bird bones are a clear indication that something is seriously wrong with the idea of slow accumulation. Instead, such fossils support the notion of rapid burial.

This statement gives us no information whatever. What is an "enormous concentration?" It couldn't be that there was a mass kill of birds at some location due to poisoning or or an ash fall, could it?

The two ash layers are separated by between 8.3 and 22.6 centimetres of shale layers.

If the standard interpretation is correct, then the number of shale layers between the ash layers should be the same throughout the Green River basin, since the number of years between the two eruptions would be the same.

However, the geologists found that the number of shale layers between the ash beds varied from 1160 to 1568, with the number of layers increasing by up to 35% from the basin centre to the basin margin! The investigators concluded that this was inconsistent with the idea of seasonal ‘varve’ deposition in a stagnant lake.

What switch. Garner talks about shale layers three times in three paragraphs, but then they suddenly become varves. This is also interesting in light of the fact that Garner told us above that some parts of the Green River Formation perhaps don't even have varves. So why should one location be identical to another? Especially if we are not even talking about varves but shale layers? Perhaps Garner, like Howard does not understand that some laminae are not considered to be varves.

There is a large body of experimental and observational data that shows that varve-like sediments can build up very rapidly under catastrophic conditions.

Again, David, you will see that Garner is talking about "varve-like" layers. What does this mean? Is a "varve-like" layer the same as a varve? We are left to our imaginations on this one. A geologist would say no. What do you think a layman has been led to believe?

Garner: Another example comes from a Swiss lake, in which up to five pairs of layers were found to build up in a single year, deposited by rapid underflows of turbid water.

Here, Garner, equivocates. Are these paired layers varves? Clearly no. They are turbidites, one of the most recognizable sedimentary features in all of geology. I remember being taught about how to recognize turbidites in my first geology class over 30 years ago. Garner's errors here are egregious.

Garner goes on:

Given the right conditions, thinly-laminated muddy sediments can and do form by rapid sedimentation. Contrary to claims by old-earth proponents, long periods of time are not demanded.

So, Garner has discovered that thinly-laminated sediments might form rapidly. Do you think this is a great revelation to geologists? And what about varves? I thought that was the subject of this essay, not thinly-laminated sediments. This reminds me of the experiments by Brethault et al. reported by Howard in the first link you gave us. This work was hardly earth shaking and I think most geologist wonder how it had anything to do with anything.

David says: Someone suggested the fish sank in the mud and were fossilized -- if so this would have disturbed many varves above and around the fish fossil and this disturbance would be evident. My impression is that this is not so.

There is nothing at this time to tie the varved sediments to the fossils. Perhaps you have some reference that can do this, but all of the GRF fossils that I have seen are not in varved sediments. And who says that you cannot disturb varved sediments? And maybe disturbance is evident. Do you have references to this idea? Seriously, I would be interested in seeing such references.

David: (Also the preservation of wood in the Black Sea is not relevant since cellulose is likely to preserve more than the soft parts of living organisms. I'd be curious to know if there is any lake today in which such large fossils including soft flesh are forming and this lake lays down such thin varves with no evidence of disturbance.)

What soft parts do we have preserved in the Green River fossils? All I have seen is replaced bone fragments. And Garner discusses the presbyornis bone concentrations. I have no references of presently deposited, varved sediments. Just guessing, I would think they are not uncommon.

David: (I also found a quote from the literature that says that the salt deposits in the Green River formation are not evaporates -- will try to track it down -- this calls into question the lake drying up many times.)

This occurs later in your post. This theory needs to be discounted for the time being since mantle emanations should carry something other than sodium, aluminum and chlorine. My references to the trona deposits are in storage right now, but I can assure you that this is a vanishingly small minority viewpoint. Maybe you have something more definitive.

I will try to get to your third link later.

 

EARL DETRA

Helen says:
I had the opportunity to have lunch with Dr. Elaine Kennedy, geologist at GRI, last week, and I asked her about varves.

Sorry, I am not familar with GRI.


In essence she said that although varves were known to have the dark and light alternating bands, other depositions could do this as well and that the distinctions between varves, rhythmites, and any forms of layering becomes quite, if you will exuse the expression, muddy. Different explanations trade places regarding different areas depending on different ideas and discoveries. In short, there is almost no exact way to look at any series of thin layers and say "these are varves."

Very good. There are indeed other ways to produce light and dark banding. That is why I prefer to go with someone who has worked in an area for a long time and can put the layering in context. Personally, I was never convinced that there were varves in the Green River Formation. If someone says so, I will defer to them, but with skepticism. You will notice that Dr. Kennedy does not define varves by grain size, or lamination size as the references that David suggested. This indicates a degree of credibility.

As for the Green River formations, the current thinking among many geologists is that they are definitely NOT varves.

Good. I would go with that, though there could be places where they might show up on a small scale. The depositional environment just doesn't seem right to me. By the way, I think more has been said about "varves" in the GRF by creationists than by evolutionists, by the way.


There are too many evidences going against them, including multistrata (or polystrate) fossils, differing numbers of varves per unit area in different sections, and the impossibility of that many years of uninterupted layering.

In the Green River Formation, perhaps. However, there are places where varves do exist. But I notice that you are simply reiterating the usual arguments that do not necessarily hold water. Are these directly from Dr. Kennedy also? As far as the "polystrate" fossils, I thought you said in a previous post that the fish were not found with varves anyway, making the point kind of moot.


Thus, while varves do exist, certainly, they cannot always be defined as clearly as some here would like them to be. She also mentioned that those geologists who said they could, know better.

I fail to see where anyone here has actually identified varves, particularly in the GRF. But for a true identification of varves I would not trust myself, either. I would prefer to go with a reputable sedimentologist who has experience in a particular region.

So, anyway,it sounds like Dr. Kennedy agrees that varves can and do exist. No one ever said it was easy to identify them, at least not I.

 

THE BARBARIAN
I wonder if Dr. Kennedy had any comment on Lake Suigetsu in Japan, where
over 40,000 years of varves were recently analyzed to calibrate C-14 dating
data.

We know that those are varves for two reasons:

1. The distribution of pollen in the varves confirms that they are being
laid down in a summer/winter sequences.

2. The process is still happening, and yes, they are varves, and being laid
down annually in couplets.

I don't know if anyone knows just how far down these varves go, but they
have been most useful in assuring that C-14 methods are accurate. And they
invalidate the idea of a young Earth.

 

KEVIN KLEIN

Helen wrote:

Just because they are not varves does not mean that a thousand-year timescale for their formation is a reasonable hypothesis. There are millions of layers in the Green River formation. There does not exist any plausible theory for how these uniform alternating layers could be laid down on a time scale compatible with a young earth. Furthermore, any rapid deposition theory must better explain the evidence than existing theories based on known seasonal and near-seasonal deposition processes. Without any plausible theories for rapid deposition, we must conclude that the Green River formation is much older than yound earth models allow.

Earlier in this thread I gave you expert testimony (Dr. Buchheim of LLU) that these fossils do not exist. Your continued use of this claim since then seems rather dishonest.

 

DAVID PLAISTED

I looked up some articles about varves and the Green River formation
in the literature. Here is what I found:
An example of a very well preserved fossil in the Green River formation,
from:

The first Esox (Esocidae : Teleostei) from the Eocene Green River
Formation, and a brief review of esocid fishes Grande L JOURNAL OF
VERTEBRATE PALEONTOLOGY 19 (2): 271-292 JUN 14 1999

Discussion of the variable states of preservation of fossils in the
Green River formation; this claims that burial, or cold water without
much oxygen, explains the good state of preservation of the fossils.
From:

PALEOLIMNOLOGY AND TAPHONOMY OF SOME FISH DEPOSITS IN FOSSIL AND UINTA
LAKES OF THE EOCENE GREEN RIVER FORMATION, UTAH AND WYOMING FERBER CT,
WELLS NA PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 117 (3-4):
185-210 SEP 1995

An example of a well-preserved fossil in the Green River formation,
from:

A unique and complete polemoniaceous plant from the middle Eocene of
Utah, USA Lott TA, Manchester SR, Dilcher DL REVIEW OF PALAEOBOTANY
AND PALYNOLOGY 104 (1): 39-49 NOV 1998

Note -- I gave some web links earlier with other examples of well
preserved fossils from the Green River formation.

An article analyzing in which parts of the Green River formation well
preserved fossils are likely to be found:

DISCRIMINANT-ANALYSIS OF FISH-BEARING DEPOSITS IN THE EOCENE GREEN
RIVER FORMATION OF UTAH AND WYOMING WELLS NA, FERBER CT, OHMAN JC
PALAIOS 8 (1): 81-100 FEB 1993

The following article is the one claiming a million year record of
varves in the Green River formation, from:

CYCLICITY IN THE GREEN RIVER FORMATION (LACUSTRINE-EOCENE) OF WYOMING
FISCHER AG, ROBERTS LT JOURNAL OF SEDIMENTARY PETROLOGY 61 (7):
1146-1154 DEC 1991

This also mentions that the varves are made of oil shale. This must
be the article that the folks at talk.origins have seized on to argue
that life is at least a million years old -- I agree that the
literature does not make much of this, in general, but it has to be
discussed because it is often used against Biblical creationists.

An article discussing possible microbial mats having an influence
in the Black Shale deposits of the Green River formation:

Microbial mats in terrigenous clastics: The challenge of
identification in the rock record Schieber J PALAIOS 14 (1): 3-12 FEB
1999

A discussion of kerogen (a kind of organic material) in the Green
River formation:

OPTICAL DESCRIPTION OF AMORPHOUS KEROGEN IN BOTH THIN-SECTIONS AND
ISOLATED KEROGEN PREPARATIONS OF PRECAMBRIAN TO EOCENE SHALE SAMPLES
THOMPSONRIZER CL PRECAMBRIAN RESEARCH 61 (3-4): 181-190 MAR 1993

I did not find any mention that well preserved fossils are found in
varves or laminae in the Green River formation -- I will have to look
more closely at Green River fossils in museums and books in the
future to see if this is the case.

Dave Plaisted

* * *

from a second email

Here are some references about fossils found in varves, but not in the
Green River formation. The first reference mentions fossils found in
varves and that generally they are not well preserved, but at certain
times the fossils were very well preserved, possibly because of very
cold conditions with poor circulation. It would be worth looking at
this one in more detail:
Seven centuries of taphonomic variation in Eocene freshwater fishes
preserved in varves: Paleoenvironments and temporal averaging Wilson
MVH, Barton DG PALEOBIOLOGY 22 (4): 535-542 FAL 1996

The following article also discusses well preserved fossils in varves
(but not in the Green River formation) and gives a long chronology
which most Biblical creationists would dispute:

SHORT-TERM PALEOCLIMATIC FLUCTUATIONS EXPRESSED IN LOWER MISSISSIPPIAN
RAMP-SLOPE DEPOSITS, SOUTHWESTERN MONTANA ELRICK M, READ JF, CORUH C
GEOLOGY 19 (8): 799-802 AUG 1991

The following reference talks about problems in aligning different
varve chronologies; in general, they do not agree very well:

An evaluation of the late Weichselian Swedish varve chronology based
on cross-correlation analysis Holmquist B, Wohlfarth B GFF 120: 35-46
Part 1 MAR 1998

[ March 14, 2002, 02:51 PM: Message edited by: Barnabas ]

 

HELEN

Earl,
GRI is the Geoscience Research Institute
http://www.grisda.org/
(go into “About GRI”, and “Reports” for more information. They are
highly respected in the field of geology especially)

You will find Dr. Elaine Kennedy with a link on the “About GRI” page.
She just got back from studying the dinosaur nests in Argentina. Her
specialty is sedimentology.

The points I mentioned were points we talked about together, not things
she “told” me.

And yes, of course she agrees that varves can and do exist!

Barbarian,
She has not, to the best of my knowledge, seen or studied Lake Suigetsu
in Japan. You might want to email her and ask her about her opinion,
however.

By the way, though, pollen sequences can be the result of tidal actions
during the spring, changing winds, and a number of other things. They
are indicators that what is being seen MAY be varves, but they are not
proof of it.

Kevin,
Yes, there is an explanation for millions of layers in a short amount of
time: a combination of storm and tidal action is adequate for a good
many alternating layers in a short amount of time. Interestingly,
Genesis 8:1-3, in the Hebrew, indicates that after the Flood the waters
receded and receded. This is commonly translated as “continually
receded” but according to Dr. Bernard Northrup, who is a Hebrew scholar,
the meaning strongly indicates a back and forth movement during
recession.

As far as the fossils go, there are those who claim then and those who
do not. I have not been there; I do not know. Have you been there? As
long as there are such strong disagreements, and from those in the field
itself, do we simply believe those who agree with us?

And as far as the Grand Canyon is concerned no, it does NOT indicate
“many years of uninterrupted layering.” Especially when, by ‘many’ I am
quite sure you mean millions. That is the interpretation given to these
layers. That is not the only interpretation, however. We know for a
fact that rapid layering can occur in dramatic fashion, and this has
been discussed in the literature for a long time.

 

EARL DETRA

David: The following article is the one claiming a million year record of
varves in the Green River formation, from:

Okay, let's read it.

CYCLICITY IN THE GREEN RIVER FORMATION (LACUSTRINE-EOCENE) OF WYOMING
FISCHER AG, ROBERTS LT JOURNAL OF SEDIMENTARY PETROLOGY 61 (7):
1146-1154 DEC 1991
Abstract: Basinal facies of the Green River Formation have two main modes, lacustrine and playa. The lacustrine mode (Tipton and Laney members) accumulated mainly varved oil shale. Here annual cycles are recorded as varves. Variations in valve thickness demonstrate El Nino (ENSO)-type and sunspot cycles (Ripepe et al., this volume). Milankovitch-scale cycles are not obvious in lithic variations, but gamma ray logs record 1) precessional variations with a mean period (valve-timed) of 19.5 ka, and 2) a bundling of these in the ca. 100 ka eccentricity cycle. In the plava mode (Wilkins Peak Member), the lithic succession oil shale-trona-dolomitic marlstone records the precessional drying up of a lake and is again bundled in sets of 5, by the 100 ka eccentricity rhythm. The Tipton Member 80persisted for 450 ka, the Wilkins Peak Member for ca. 1 Ma.

Sorry, but that is NOT what it says. You will note that the varved sediments are found in the lacustrine facies (Tipton and Laney members). It says nothing about varves in the Wilkins Peak Member (playa facies) which has been estimated to have persisted for a million years based on Milankovitch cycles, and not varves. This may refer back to the part of the discussion we had where there is some dispute as to the presence of varves in the GRF. There may be varves in some parts but not others. It is a rather extensive unit.

Thank you for the other references. I wish I have more time to follow up on them. If you have any particular point you would like to discuss, I would be willing to do so, but Milankovitch cycles are a bit beyond my repertoire.

 

KEVIN KLEIN

The GRF is the remains of a very large ancient lake system. The formation is characterized by a very thick layer of finely laminated rock. This laminated rock is the source of many excellent fossil fish, plants, and other creatures and is also one of the largest deposits of oil shale in the world. Estimates on the total number of layers present in the GRF range from a low of 6 million to a high of 20 million.
W. H. Bradley was the first to suggest in 1929 that each layer was the result of a seasonal deposition process, which means that the layers are described by geologists as "varves". Obviously such a finding is a serious problem for the young-earth creationist. More recent work, particularly by Dr. Paul Buchheim, has called into question whether the layers are true varves or whether they might in fact be deposited more frequently. Helen has exploited this uncertainty in an attempt to preserve her worldview, but in fact the situation for her is not good.

While it is indeed likely that some or all of the Green River formations are not varves, there is still an overwhelming amount of evidence that they were formed over a very long period of time.

1. Stratigraphy

There do exist known mechanisms that can produce layered sediments very rapidly. Unfortunately these mechanisms leave telltale signs, none of which are present in the Green River formation. Specifically, rapidly deposited formations like turbidites usually show:

- Vertically sorted grain sizes, with the smallest grains sorting below the larger ones. Layers in the GRF show no vertical sorting, although there is some sorting horizontally.

- Ripple marks produced by the fast flowing currents and sediment flows. The layers in the GRF are very smooth and show little evidence of ripples.

- "Sole marks", which come in a variety of forms, caused by uneven settling of the rapidly deposited sediments.

Generally speaking, the layers in the GRF are very flat and very uniform and exhibit none of the irregularities that characterize rapidly deposited formations.

2. Chemistry

The layers in the GRF follow an alternating light/dark pattern. Both layers are composed primarily of very small crystals of carbonate minerals. These types of crystals have been observed to form in modern lake systems when inflowing water rich in carbonates encounters lake water that is slightly alkaline. A chemical reaction causes the carbonate to precipitate out of the water and collect on the lake bottom.
The dark layers are of the same mineral composition but are much higher in organic material. This organic material comes primarily from algae, bacteria, and other living matter that decays and slowly filters down to the lake bottom.

One general model for varves, for example, is that the light-colored layers accumulate during the wet season when large amounts of inflowing water bring in large amounts of carbonate which precipitates out onto the lake bottom. During the drier season, organic deposition increases and causes the formation of the darker layers.
The recent work by Buchheim indicates that processes other than strictly seasonal ones may have operated in the lake. Most likely large storms brought increased runoff that temporarily caused some sections of the lake to switch to more carbonate-rich deposition.

The process by which the GRF carbonate layers are formed is reasonably well understood, and it is far from rapid. The production of sufficient organic material alone is a limiting factor that indicates a lower bound on layer formation of several months.

3. Fossils

The GRF is one of the largest and most important known sources of freshwater fish fossils. In addition to fish, however, there are large numbers of fossil plants, birds, and even one of the earliest fossilized bats.

Unfortunately for the young-earther, fossils are generally inconsistent with rapidly formed deposits. The reason is simple - any animals not already dead are probably going to get out of the way. Any plant material that is not already on the lake bottom is not suddenly going to drop off of the trees and work its way into the formation. For this reason, rapidly-deposited sedminents typically have few fossils.

Another important type of fossil evidence difficult to explain in a rapid deposition scenario is the presence of fossil animal tracks, primarily birds. Most models of rapid layer deposition leave little if any time for tracks to be laid. Many other rapid deposition models are deep water phenomena that can't possibly create fossil tracks at all.

The lakes of the GRF, on the other hand, were a perfect environment for fossilization. Chemical analysis indicates that the lake bottom was often anoxic. This prevents fossils from decomposing and keeps scavengers from disturbing the remains. The slow, steady rain of carbonate precipitates provides a perfect mechanism to bury and eventually fossilize the remains.

4. Stromatolites

Another piece of evidence for an old earth in the GRF is fossil stromatolites. Stromatolites are similar to coral, but are formed by a variety of bacterial and algal organisms. Like corals, they develop very slowly. Because the stromatolites are found at many different layers in the GRF, this is strong evidence that the lakes were stable enough, and the layers deposited slowly enough, for the stromatolites to form. The finding of stromatolites is completely incompatible with any rapid deposition scenario.

So there you have it. Yes, indeed, the layers in the GRF may not be varves. There remains a wealth of evidence, however, the the GRF was formed very slowly over an enormously long period of time. Anyone who claims that the earth is less than 10k years old must provide a compelling theory for the rapid deposition of this formation that is both consistent with the observed data and that explains the characteristics of the formation more effectively than the existing slow deposition models.

Good luck.

* * *

from an email received later

Helen wrote:

"Highly respected" by whom exactly? How many research projects are they doing for petroleum companies? or mining companies?

Except the GRF is not consistent with any known rapid deposition mechanism. Oh, and lakes don't have tides. (Not significant ones, anyway).

Dr. Buchheim's specific claim was that polystrate fossils were not documented in the professional literature. Why persist in making a claim that has not been documented? Controversy in interpretation is one thing, but you are making a claim of fact for which there is no documentation.

And as I said before, these rapid layering mechanisms have known characteristics and the GRF is not compaitble with them. Just because there exists a rapid layering mechanism doesn't free you from the burden of actually demonstrating that that mechanism is applicable to the formation in question.

 

DAVID PLAISTED

Kevin Klein says that well preserved fossils could form in the Green
River formation because the water was anoxic (oxygen poor). Earlier
I gave a reference from an article at
http://www.answersingenesis.org/Docs/213.asp to experiments by the
Chicago Natural History museum in which fish decay and bones disconnect
even in oxygen poor conditions, after six and a half days. If the water
were cold and oxygen poor this process might slow down some, but should
not last years. Maybe someone could see how many well preserved fish there
are on the bottom of the Black Sea?
It was asserted that the lake was also chemically favorable to fossilization.
But I read some references that varves do not form in sea water which would
limit the kinds of chemicals that could be present. It also seems strange
that such chemicals would be present only at the lake bottom and not at the
top where there was claimed to be so much organic matter.

Dave Plaisted

 

EARL DETRA


David: Kevin Klein says that well preserved fossils could form in the Green River formation because the water was anoxic (oxygen poor).

That is one possibility. I do not necessarily subscribe to it. I don't think it is necessary. There certainly were some anoxic zones in the GRF basin.

Earlier I gave a reference from an article at http://www.answersingenesis.org/Docs/213.asp to experiments by the Chicago Natural History museum in which fish decay and bones disconnect even in oxygen poor conditions, after six and a half days. If the water were cold and oxygen poor this process might slow down some, but should not last years.

As I remember, the study did not say what happened to those bones, did it? I don't suppose that they could permineralize to form the fossils that we see today. Yes, the study said that the soft parts decayed away, but exactly where do we see soft body parts in the GRF fossils? I don't remember them saying much about disarticulation.

Maybe someone could see how many well preserved fish there are on the bottom of the Black Sea?

Ah, but they don't have to be well-preserved. That is the whole point.

It was asserted that the lake was also chemically favorable to fossilization. But I read some references that varves do not form in sea water which would limit the kinds of chemicals that could be present.

Now you are juxtaposing the fossils with the varves. I thought we had concluded that there were no varves where the fossils are found. And I see no reason why a brine-loaded solution would not aid in permineralization, perhaps not, but I don't see this as a major point.

It also seems strange that such chemicals would be present only at the lake bottom and not at the top where there was claimed to be so much organic matter.

We have been over this, too. There are depth discontinuities in temperature and composition in many lakes. Brine saturated water would even be expected to collect in deeper parts of a lake. However, once again, this appears to be a minor point. All kinds of organisms live in brackish water so having some kind of separation is not a critical point. There are many factors that lead to preservation in the fossil record.

 

KEVIN KLEIN

David Plaisted wrote:

The article you referenced just has AiG's one-sentence summary of the paper's conclusion. Even if AiG was a trustworthy source, the real paper probably has many more subtleties and complexities than can be conveyed in a one-sentence summary. Is one sentence of hearsay from AiG really a big problem?

The lakes that formed the GRF were fresh water, not sea water, so I don't think there is any problem there.

As to the stratification of the lakes, the following link describes a set of lakes in Africa that shows just how distinct this stratification can be:

http://www.biology.lsa.umich.edu/~gwk/research/nyos.html

It's really quite common for lakes to be chemically and thermally stratified.