Using Coral as a Clock (Update 30.4.2007)

Please forgive me I forgot to update calculated values in the table.
I put correct update below. (The text is made by the WORD program.)

Hannu

My Updating Notes (30.4.2007):

I. The coefficient of the asymptotic straight line for the month
formula is
-7
about 3.53 * 10 from my calculations (1, Allen 1973) and the
little
uncertain period of oscillation about this line is roughly
4
429.4 * 10 centuries from (Pannella MacClintoc and Thompson 1968).
-7 4
P(T) = 29.53 - 3.53 * 10 * ( 1 - e*sin ( 2 P T / (429.4 * 10 )))*
T

P(T)= number of mean solar days per synodic month at a
certain
point T of time
0 = e = 1, (e = 1 in first approximation, e = 0 in second
approx.)
P = 3.14159 radians
(This month formula is not used because it is still under testings.
Existence of this oscillation is needed to be confirmed with more
complete
fossil data and with more accurate age determinations.)

(The coefficient is 2.60 * 10^(-7) from (Scrutton 1978) and 4.29 *
10^(-7)
from (Pannella MacClintoc and Thompson 1968) and 3.50 * 10^(-7) from
(Scrutton 1964, 1970, Kulp 1961).)




II.

(In the text wrong word "speeds up" is corrected to "slows down".)


III.

The depositional age of the Gunflint Formation is
1878.3 Ma +- 1.3 Ma (2) (The sample YPM-IP-28510 & YPM-IP-28511
is only complete test point of stromatolites.)

MAINLY PANNELLA'S STROMATOLITE DATA:

TABLE 9

MAINLY PANNELLA'S STROMATOLITE DATA:
4
1. = T / 10 (centuries)
2. = calculated value from the first time formula (days/year)
3. = calculated value from the second time formula (days/year)
7. = experimental value (Pannella 1972 a).
9. = the code of the fossil specimen
10. = Highest count=(days/month)?, (Pannella 1972 a and Pannella
1972 b).
11. = Mode=(days/(month/4))-(days/(month/2))-(days/month) ?,
(Pannella 1972 a and Pannella 1972 b ).
12. = Tidal cycles per year = (months/year) ?,
(Pannella 1972 a and Pannella 1972 b).
U = Upper, M = Middle, L = Lower.
YPM-IP = The collection of Division of Invertebrate Paleontology,
Peabody Museum, Yale University





1. 2. 3. 7. 10. 11. 12. 9.

----------------------------------------------------------------------------
-1878 516.83 580.71 504-546 39 18-36 14 YPM-IP-28510
YPM-IP-28511

----------------------------------------------------------------------------
(Note. 1. Error limits = +-1.3*10^4, 12. 28 fortnights per tropical
year?,
14 synodic months per tropical year?)

----------------------------------------------------------------------------
-(2715- 567.65 741.90 41 10-20-40 UCLA-BUL-7
-2672)(565.50) (731.79) (= P.P.R.G.
253)

----------------------------------------------------------------------------

(Note. 1. -(2715 +- 15)*10^4, (2672 +-12)*10^4, 2.,3. 567.65 and
741.90
corresponds to T = -2715*10^4 centuries and 565.50 and 731.79
corresponds
to T = -2672*10^4 centuries, 7. 504=14*36, 546=14*39.)

Somewhat uncertain data about UCLA-Bul-7 (The sample
UCLA-Bul-7 is a incomplete test point. I recall that possible
"year" marks were not found by Pannella (Pannella 1972 a, b)):

A. Huntsman limestone stromatolites of MacGregor belong in the
Upper Bulawayan Greenstones (3)(if I can rely on J.F.Wilson, this
needs still to be confirmed):

"J.F.W.'s correlations across the greenstone belts also allow the
rationalization of the known occurrences of Rhodesian Archean
stromatolites which now number five (Fig.1).
All of these occur in the Upper Greenstones. ... Three occur in
limestones
above the tholeiitic pile; one at Belingwe, one south-east of
Redcliff ...
and one the Huntsmann limestone stromatolites of MacGregor, some
60 km north of Bulawayo."

B. Age of the Upper Bulawayan Greenstones (4) (this needs still to
be confirmed with more local age data):

"Timespan of deposition of Upper Bulawayan Greenstones is
2715 Ma +- 15 Ma (Iron Mask Formation, ZIM-74)- 2672 Ma +- 12 Ma
(Harare-Shamva greenstone sequence ,,Black Cat porphyry", ZIM-29)"
(The Stromatolite UCLA-Bul-7 (found by K.A. Kvenvolden from one
tailings
of pile of Huntsman Limestone Quarries) could be a little older than
this
age, because it could originate little below Upper Bulawayan
Greenstones in Huntsman Limestone Quarries (5)?)

C. About geology of the Bulawayan Supergroup is in the reference (6)
written by M.D. Prendergast.


References:

1. Poropudas Hannu, 1996.
Harrastelijan ajatuksia päivän, kuukauden ja vuoden pituudesta
muinaisina aikoina.
Geologi, 4-5/1996, Pages 92-96.

2. Fralick Philip, Davis Don W., and Kissin Stephen A. 2002.
The age of the Gunflint Formation, Ontario, Canada:
single zircon U-Pb age determinations from reworked volcanic ash.
Can. J. Earth Sci. vol. 39: 1085-1091.

3. Wilson, J.F. et al, 1978.
Granite-greenstone terrain of the Rhodesian Archean craton.
Nature, vol. 271, 1978, 23-27.

4. Jelsma,H.A., Vinyu,M.L., Valbracht,P.J., Davies,G.R.,
Wijbrans,J.R., Verdurmen,E.A.T., 1996.
Constraints on Archean crustal evolution of the Zimbabwe craton:
a U-Pb zircon, Sm-Nd and Pb-Pb whole rock isotope study.
Contrib. Mineral Petrol. (1996) 124: 55-70.

5. Bond,G., Wilson,J.F. & Winall,N.J., 1973.
Age of the Huntsman Limestone (Bulawayan) Stromatolites.
Nature 244, 275-276. (the map of the Huntsman Limestone Quarries).

6. Prendergast,M.D., 2004.
The Bulawayan Supergroup: a late Archean passive margin-related
large igneous province in the Zimbabwe craton.
Journal of the Geological Society, London, Vol. 161,
2004, pp. 431-445. Printed in Great Britain.