CYCLICITIES OF VARVES
"On the premise that sequential changes in varve thickness offer
a proxy for climatic variations, we investigated varve thickness
in three core segments from the distal lacustrine oil shales
(Tipton and Laney members) of the Green River Formation, by means
of an image analysis program. Of two strong bimodal
periodicities one, at 4.8-5.6 years, is interpreted as an El Nino
type (ENSO) phenomenon of atmospheric dynamics, while the other,
at 10.4-14.7 years, is interpreted as the sunspot cycle,
originally recognized in this formation by Bradley (1929,1931).
Weaker periodicities may exist at ca.8 and 33 years - the latter
also recognized by Bradley. Taken in conjunction with the work
of Bradley (1929,1931) and of Crowley et al. (1986), this
suggests that some but not all of the oil shale of the Green
River Formation is truly varved and can be used to infer climatic
time-series."~Maurizio Ripepe, Lillian t. Roberts, and Alfred G.
Fischer, "Enso and Sunspot Cycles in Varved Eocene Oil Shales
from Image Analysis," Journal of Sedimentary Petrology, 61:7,
December, 1991, p. 1155.
**
sunspot cycle in green river formation
" The ca. 12-year periodicity, dominant in these spectra, is
presumably the 11-year cycle of Bradley (1929) and the 10.4-year
cycle of Crowley et al. (1986). We too attribute it to the
sunspot cycle. While the sunspot cycle and its tie to magnetic
reversals in the sun are well established from historical
observations, both the nature of the signal emitted by the sun
and its efffects on the outer Earth remain controversial.
" The ca. 5-year cycle was interpreted by Crowley et al.
(1986) as an harmonic of the sunspot cycle, an analytical
artifact. However, this cycle is visible in some of the peels
(Fig. 2), and in the raw curve of varve thicknesses, more so than
the ca. 12-year cycle."~Maurizio Ripepe, Lillian T. Roberts, and
Alfred G. Fischer, "Enso and Sunspot Cycles in Varved Eocene Oil
Shales from Image Analysis," Journal of Sedimentary Petrology,
61:7, December, 1991, p. 1162.
**
green river formation cyclicities
" The cyclicities discussed are developed at seven levels.
High-frequency cycles in the Tipton and Laney members include the
annual cycle expressed in varving (1), the grouping of varves
into El Nino (ENSO)-type (5.8) year cycles (2), their grouping
into sunspot cycles (3), and their grouping into 30-year
cycles(4). Low-frequencey cycles from the Milankovitch frequency
band are seen in the Tipton and Wilkins Peak members, and include
the precessional 20 ka cycle (5) and the ca. 100 ka eccentricity
cycle (6). Cycle categories 1,5, and 6 are discussed here, while
2,3 and 4 are dealt with the Ripepe et al."~Alfred G. Fischer and
Lillian T. Roberts, "Cyclicity in the Green River Formation
(Lacustrine Eocene) of Wyoming," Journal of Sedimentary
Petrology, 61:7, December 1991, p.1147
Here are some other sources for info on the Green River and what it means to
the young-earth viewpoint. There are about 2600 feet of strata and 13
million varves. (Clark and Stearn, Geological Evolution of North America,
1960, p. 219) This means that the average laminae is .06 mm. Fossil fish
from the laminae of this formation are sold around the world.
NOT A TURBIDITE DEPOSIT
The young earth creationists, like Henry Morris, (Genesis Flood p. 427) try
to say that this is a turbidite deposit but the varves alternate in
lithology in a fashion inconsistent with that explanation. Turbidites are
generally sand/shale. This is carbonate/organic material.
" Studies of the
lithology of the Green River formation have shown that pairs of
alternating light and dark bands (varves) within the rocks
represent annual deposition. The light bands are composed
chiefly of carbonates believed to have been the result of summer
deposition, and the dark bands composed predominately of organic
matter thought to have settled out during winter seasons. One
varve may have a thickness of only a few millimeters. "~Bruce R. Erickson,
"Fossil Bird Tracks from
Utah," Museum Observer, 5:7 unnumbered pages (1967), in William
A. S. Sarjeant Terretrial Trace Fossils, (Stroudsburg: Hutchinson
Ross Publishing Co., 1983), p. 146.
TRACKS.
Also around the edges of the ancient Lake Gosuite (which is what formed the
Green River formation ) there are numerous tracks. A turbidite is a deep
water deposit and unless the animals were exceptionally long-legged this
explanation is inconsistent with the tracks. See the above article and note
the Flamingo nests in the following stuff:
A nesting colony of Eocene flamingoes was found in the Green
River Basin. "The fossil bird concentration occurs 104 feet
below the base of the basal oil shales of the Laney Shale Member
of the Green River Formation in a grayish-green silty claystone.
The site is in the S 1/2 sec 24, T 25N, R. 102 W. " p. 163
"Many fragments of aquatic turtle shells and crocodile bones plus
fish remains attest to the aquatic environment, and an extensive
mud flat submerged under a few feet of water is indicated.
Judging from the large number of algal encrusted logs and
branches the expanding waters probably drowned a forest. A
similar situation exists on Lake Nakuru." p. 163
"Modern flamingos are primarily filter feeders, and the main diet
consists of algae and microorganisms obtained from the diet
consists of algae and microorganisms obtained from the water and
bottom muds. Occasionally, however, flamingos will take a
variety of small mollusks, crustaceans, worms and small fish.
Stomach contents usually include an abundance of organic muds.
There is suggestive evidence that the Green River Birds had
somewhat similar habits. Within the matrix of the bird quarry,
and mixed among the bones were hundreds of small clay pellets.
At first these were thought to be coprolites left by small
carnivores. Their abundance and composition, however, seemed
contrary to that interpretation. The mystery may have been
partially solved when we discovered almost identical pellets on
the shores of east African Lakes where hundreds of thousands of
flamingos concentrated. p. 163-164
"That the green river flamingo locality was a nesting site is
proven by the abundant egg shell fragments found among the bones.
p. 164
"Another interesting feature of this fossil site is the
occurrence of many logs and branches that are heavily encrusted
presumably by algae." p. 164
"The lake was saline as known from many lines of evidence but now
supported by the occurrence of flamingos, birds which are today
restricted to saline lakes." ~ p. 164
Paul O. Mcgrew and Alan Feduccia "A Preliminary Report on a
Nesting Colony of Eocene Birds" 25th Field Conference Wyoming
Geological Association Guidebook 1973.
Radioactive dating supports the yearly basis of the varves. A 55 meter
interval had a volcanic tuff above it and below it and each tuff was dated.
The top of this section dates at 46.2 million years and 55 meters lower
dates 47.2 million years. thus the depositional rate is:
55000 mm/1000000 yr=.055 mm/yr. Which is quite close to the average
thickness of the varves--see above.
~Robert R. Remy, "Stratigraphy of the Eocene Part of the Green
River Formation in the South-Central Part of the Uinta Basin,
Utah," U.S. Geological Survey Bulletin 1787, p. BB20.
>Question 1: My Norwegian astrophysics textbook says the period of the
>earth's precession is around 23000 years. Is the point then that 12000 is
>about 50% of 23000, or is something very wrong here?
I don't know where Hayward got this info.
>
>Question 2: Hayward says nothing about the 2000 year period of varve
>thickness variation. Does anyone know the explanation?
>
I don't know what the 2000 year cyclicity could be. It is not an
astronomical cycle and I have never seen that value in the geologic literature.
>Question 3: Have any of you evaluated any of the YEC explanations for
>the GR varves?
See stuff above
Or the YEC explanations for coral reefs? If so, how good
>are they?
terrible. But ask a specific question about their explanation.
>
>FYI: I am a member of ASA, but do not subscribe to asa@calvin.edu
>(actually, I browsed the ASA web pages to figure out how to do that,
>but could not find any pertinent information ....). Therefore, please reply
>directly to me at ole.anfindsen@fou.telenor.no, and not to the list.
I am going to put it on the list also because there are people who might
have an interest in this.
glenn
Adam, Apes, and Anthropology: Finding the Soul of Fossil Man
and
Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm