>I am going to suggest that the observational data gives us local
>columns. To show the existence of a global geological column, it is
>necessary to go beyond "observations" and to address the issue of
>interpretating data. We need to clarify the principles behind making
>correlations, and to subject the principles to critical scrutiny.
>
This is difficult, but I think I can do it simply. the conclusion is that we
find rocks of similar lithologies, similar depositional patterns, containing
the same fossils, piled in the same order around the world. It is NOT simply
the fossils which are found in the same order. Fossils AND lithologies AND
depositional patterns on a large scale are found in the same order around the
world. Because of this there is no circularity. Details below.
There are 23+ basins around the world where the entire column is found. For
your information the ones I have been able to document are:
The Ghadames Basin in Libya
The Beni Mellal Basin in Morrocco
The Tunisian Basin in Tunisia
The Oman Interior Basin in Oman
The Western Desert Basin in Egypt
The Adana Basin in Turkey
The Iskenderun Basin in Turkey
The Moesian Platform in Bulgaria
The Carpathian Basin in Poland
The Baltic Basin in the USSR
The Yeniseiy-Khatanga Basin in the USSR
The Farah Basin in Afghanistan
The Helmand Basin in Afghanistan
The Yazd-Kerman-Tabas Basin in Iran
The Manhai-Subei Basin in China
The Jiuxi Basin China
The Tung t'in - Yuan Shui Basin China
The Tarim Basin China
The Szechwan Basin China
The Yukon-Porcupine Province Alaska
The Williston Basin in North Dakota
The Tampico Embayment Mexico
The Bogata Basin Colombia
How do we correlate? The first thing which can be correlated is the order of
the fossils in each of the basins. By this I mean once can observe that in
each basin fish appear long before mammals, invertebrates appear before
vertebrates, certain plants appears prior to angiosperms, dinosaurs appear
AFTER trilobites, etc. etc. This order, and many others far more detailed are
found in the same order in ALL the basins. I simply can not give all the
lithologiucal details but I will give some throughout the Paleozoic.
The second thing which can be correlated is lithology, that is, the type of
rock. Amazingly, the type of rock is often in the same order in various
basins. For instance, Generally speaking the Cambrian starts with a
conglomerate at the bottom, followed by a quartzite, which in turn is covered
by glauconitic sands and shale. For those that don't know, glauconite is a
mineral which is only formed in the ocean.
Above this (not immediately) is often a bed which is dolomitic, algal,
mottled, with clay rip up clasts. a rip up clast is a piece of shale that
usually was dried out and then ripped up from one place and deposited
elsewhere.
Above this (not immediately) in many basins is a sequence of red-beds with
normally anhydrites and salt. These beds straddle the Devonian/Silurian
boundary. They are the Old Red Sandstone in England, the are the Salina Grp
in New York and Michigan. Similar beds are found in the same position in
Kashmir and are called the Manturovian Suite in Siberia.
Above this (not immediately) are the nearly world-wide Devonian black shales.
These shales are highly radioactive. This bed is called the Chatanooga in the
eastern U.S., the Woodford in Oklahoma. It is found in Russia, Turkey
(Koprulu fm), China, and Brazil.
Above this is my favorite. It is a layer of crinoidal limestones which are
eroded at the top and often stained red by overlying red-beds. The Lisburne
fm of Alaska, The rundle fm of Canada, The
Madison/Leadville/Redwall/Keokuck/Burlington of the U.S. 24 iguanodon
skeletons were pulled from an erosional karst from these crinoidal limestones
in Belgium. These are found in Australia and Egypt etc.
This bed contains chert and a very peculiar type of fossil clam that does not
occur in any other formation in the world.
Coccolithic limestone, which is made up of 80-90% dead microscopic animals
occurs only in the Cretaceous. The white cliffs of Dover are the same as the
Austin Chalk upon which Dallas is built. The only difference is that your
White Cliffs have a slightly higher percentage of coccoliths. Similar fossils
are found in both your cliffs and the Austin Chalk.
(I would refer you to: Morton, G. R. (1984). Global, Continental, and
Regional Sedimentation Systems and Their Implications Creation Research
Society Quarterly. 21:23-33. for more details).
Third, there is occassionally depositional patterns which can be correlated
across these basins. The tertiary has more clastic deposition than almost any
other period. The tertiary is at the top of the geologic column. There is
clastic deposition in every age, but the Tertiary consists of a high
percentage of this type of deposition. The Pennsylvanian strata all over the
world is very cyclic in nature. This can be observed in the Donetz basin of
Russia, to the mid-continent of the US to Japan.
Finally, chemicals can be correlated. The majority of the Coal is found in
carboniferous strata. Banded iron formations are only found at the bottom of
the pile in the pre-cambrian. The iridium anomaly at the top of the Cretaceous
appears to be a world-wide event. Ratios of sulfur isotopes can be correlated
around the world (see ~Robert M. Garrels and Abraham Lerman,"Phanerozoic
cycles of Sedimentary Carbon and Sulfur", Proc. Natl. Acad. Sci. U.S.A., 78:8,
(August, 1981), p. 4655. pp 4652-4656)
These types of correlations from basin to basin help tell what rock is to be
correlated with what rock.
Frankly, Christians have been extremely derelict in their treatment of the
geologic column and most of those making such claims have never even been on a
geologic field trip.
[my part about North Dakota snipped.]
>I have no intention of disputing this. My interest is: how do you
>move from local columns to a global column? You refer to numerous
>local columns - but what are the grounds for saying the global
>pattern exists? Merely saying "every geological period" is
>represented does not do this.
>
see above, my article and Ager's The Nature of the Stratigraphical Record.
[my part snipped]
>I will agree that "proper research" has not been done. The general
>argument (by those who reject the Goelogical Column) is that there is
>an inherent tautology in the principle of correlation: ie. fossils
>are used to date the rocks, which in turn are used to date the
>fossils. Evolutionary theory is supposed to undergird the whole
>exercise. Merely presenting local columns (even "complete" ones)
>does not address the issue of HOW correlations are made.
>
I wish I could scream this from the housetops. Fossils are not the primary
means of telling which rock is older than another. The stratigraphical order
(the order they are piled up in) is THE PRIMARY MEANS OF DETERMINING WHAT ROCK
IS OLDER THAN WHICH OTHER ROCK.
When the shape of the rocks is flat or gently dipping like:
------------------d
------------------c
------------------b
------------------a
the layer (a) at the bottom is the oldest; (d) is the youngest. In cases like
this I DON'T CARE WHAT FOSSILS THE ROCKS CONTAIN. The lowest is simply the
oldest. This is what we find in most basins.
Occasionally, there are overthrusts, in which older rocks are thrusted over
younger rocks. Creationists have tried to make a lot from them. Rarely do the
creationists draw what the rocks look like for their readers. (most have never
personally seen an overthrust) In overthrust regions the roch are NEVER flat.
They look like:
region of
overthrust
| |
....../ / \ \ \
////c/b/a/\a\b\c\
//////////\\\\\\\\
/////////----------------d
////////-----------------c
///////------------------b
/////--------------------a
The letters represent layers which have unique lithological, paleontological
and depositional characteristics. a above looks like a below and so forth.
Christians often teach that overthrusts look like the first diagram. Nothing
could be further from the truth.
In all the creationists books I have read, and I have read a bunch, only two
of them attempted to diagram what an overthrust looks like. One, Eric Von
fang's Time upside down drew a diagram like the first on. He is wrong. The
other, Earth Science for Christian Schools, by Mulfinger and Snyder,
diagrammed it correctly, but stated that overthrusts do not exist.
glenn
Foundation,Fall and Flood
http://members.gnn.com/GRMorton/dmd.htm