Green River Blues
by Paul Garner
The Green River Formation of Wyoming, USA, is familiar to geologists not only for
its well-preserved fossils but also because it has come to the forefront of debate
on the age of the earth. Critics of creationism have frequently appealed to the
Green River Formation as irrefutable evidence for a multi-million-year-old earth.1,2,3
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). Each summer/winter pair of layers—called varves—would thus
represent a single year. Most geologists claim that this formation alone must have
taken several million years to be laid down. Old-earth geologist (and professing
evangelical) Dr Davis Young put it like this:
‘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.’4
Obviously, this is a serious challenge to those who believe in a young age for the
earth as indicated by Scripture (less than 10,000 years).
However, the critics (who in any case err by relying on the incomplete data of fallible
scientists, rather than the infallible God who knows all data) leave out some vital
information that sheds light on the origin of ‘varves’. As long ago
as 1961, creationists were pointing out features of the Green River Formation that
were difficult to reconcile with the conventional varve interpretation.5 For instance, well-preserved fossils are abundant and
widespread throughout the sediments. According to two conventional geologists:
‘ … fossil catfish are distributed in the Green River basin over an
area of 16,000 km2 … The catfish range in length from 11 to 24
cm, with a mean of 18 cm. Preservation is excellent. In some specimens, even the
skin and other soft parts, including the adipose fin, are well preserved.’6
Another evolutionist stated:
‘During the early to mid-1970s enormous concentrations of Presbyornis
[an extinct shorebird] have been discovered in the Green River Formation.’7
This should tell us that the Green River Formation is no ordinary lake deposit!
Modern-day lakes do not provide the conditions needed for the preservation of abundant
fossil fish and birds.
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.8
The Presbyornis fossils are even more problematic. Birds have hollow bones
that tend not to preserve well in the fossil record. How were these bird bones protected
from scavenging and decay for thousands of years until a sufficient number of the
fine annual layers had built up to bury them? ‘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.
Creationist suspicions about the validity of the varve interpretation were confirmed
in a study by two geologists published in 1988.9
Near Kemmerer in Wyoming the Green River Formation contains two volcanic ash (tuff)
layers, each about two to three centimetres thick.
A volcanic ash layer is an example of what geologists call an ‘event horizon’,
because it is laid down essentially instantaneously by a single event, in this case
a volcanic eruption. 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.
So how were the great thicknesses of finely laminated shale in the Green River Formation
laid down? Creationist geologists need to investigate the issue more closely, but
there seems to be great potential for developing a catastrophic model for the origin
of these sediments. There is a large body of experimental and observational data
that shows that varve-like sediments can build up very rapidly under catastrophic
conditions.10,11,12,13,14 For instance, in 1960 Hurricane Donna struck the
coast of southern Florida and deposited a blanket of thinly-laminated lime-mud six
inches thick.15 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.16
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.
References and notes
- A. Hayward, Creation and Evolution. The Facts and Fallacies,
Triangle, London, pp. 87– 88, 1985. Return to Text.
- D. Stoner, A New Look at an Old Earth. Schroeder Publishing,
Paramount, California, pp. 78–79, 1992. Return to Text.
- D.A. Young,‘The discovery of terrestrial history’,
in Portraits of Creation, H.J. Van Till, R.E. Snow, J.H. Stek and D.A.
Young, William B. Eerdmans, Grand Rapids, Michigan, 1990. Return to Text.
- Ref. 3, p. 77. Return to Text.
- J.C. Whitcomb and H.M. Morris, The
Genesis Flood, Presbyterian & Reformed, Phillipsburg, New Jersey, pp. 424–429,
1961. Return to Text.
- H.P. Buchheim and R.C. Surdam,‘Fossil catfish and the depositional
environment of the Green River Formation, Wyoming’, Geology 5:198,
1977. Return to Text.
- A. Feduccia,‘Presbyornis and the evolution of ducks and flamingos’,
American Scientist 66:299, 1978. Return to Text.
- R. Zangerl and E.S. Richardson,‘The paleoecological history
of two Pennsylvanian black shales‘, Fieldiana: Geology Memoirs 4,
1963. Return to Text.
- H.P. Buchheim and R. Biaggi,‘Laminae counts within a synchronous
oil shale unit: a challenge to the “varveâ€? concept’. Geological
Society of America Abstracts with Programs 20:A317, 1988.
Return to Text.
- S.A. Austin, editor, Grand Canyon. Monument to Catastrophe.
Institute for Creation Research, Santee, California, pp. 37–39, 1994.
Return to Text.
- M.J. Oard,‘Varves—the first “absoluteâ€?
chronology. Part I—historical development and the question of annual deposition’,
Creation Research Society Quarterly 29:72–80, 1992.
Return to Text.
- M.J. Oard,‘Varves—the first “absoluteâ€?
chronology. Part II—varve correlation and the post-glacial time scale’,
Creation Research Society Quarterly 29:120–125,
1992. Return to Text.
- J. Fineberg,‘From Cinderella‘s dilemma to rock slides.’,
Nature 386:323-324, 1997. Return to Text.
- H.A. Makse, S. Havlin, P.R. King and H.E. Stanley,‘Spontaneous
stratification in granular mixtures’, Nature 386:379-382,
1997. See also Sedimentation Experiments: Nature finally
catches up!. Return to Text.
- M.M. Ball, E.A. Shinn and K.W. Stockman,‘The geologic effects
of Hurricane Donna in South Florida’, Journal of Geology 75:583–597,
1967. Return to Text.
- A. Lambert and K. Hsü,‘Non-annual cycles of varve-like
sedimentation in Walensee, Switzerland’, Sedimentology 26:453–461,
1979. Return to Text.
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