© Jim Thomas,
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Layer upon uniform
layer of sediments of ancient seas. The oldest layers preserve bacteria
and colonies of blue-green algae that gave Earth its oxygen. An
orderly record of animal and plant evolution unfolds as you climb
the canyon wall.
Sincere thanks
are due to Jim Thomas, whose superb photographs and illustrations
grace this page. Further information is available at www.edu-source.com,
and more of Jim's illustrations are available for viewing and purchase
here.
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Creationists
say these strata were formed by Noah's flood...
...formed by
the ebb and flow of the flood's surges. The references below will
give the creationists' views, but simply viewing the visual evidence
makes believing "flood geology" definitely an act of faith.
Consider the simple evidence that is provided by the organization
of fossils, age gradient of the strata, and last but not least,
the occurrence of lava flows interrupting the formation of strata.
Also there is much evidence of burrowing animals making tunnels
through strata below their native layer, but never a case
of them tunneling into strata above them.
(If the strata
were formed by a single flood, then pollen would be distributed
throughout. However, the microscopic pollen fossils follow the same
order as the larger fossil evidence. Tough to explian this simple
fact away.)
For some interesting
questions about the flood myth, see flood.
A number of inks to creationist theories produced from a search
using the terms "strata caused flood"
http://www.pathlights.com/ce_encyclopedia/14flod02.htm
http://www.icr.org/pubs/imp/imp-006.htm
http://ourworld.compuserve.com/homepages/CW_Arnhem/version2/Gen7/Layers.htm
http://freethought.tamu.edu/~aasg/aleph/notes/thenderson.02.html
The Genesis
Flood by Henry M. Morris and John C. Whitcomb (1961, 518 pp.)
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But
maybe the Canyon is only 10,000 years old...
...because individuals
that interpret the bible literally believe the Earth is not older
than 6 to 10 thousand years. One claim is that they have measured
the age of a lava flow that is at the top of the Canyon is older
than the age of a lava flow at the bottom. It would be difficult
to explain how and older layer came to be above the younger strata.
However, the method they used actually measured the age of the molten
source of the lava flow, and not when the flow occurred.
The details from Matthew S. Tiscareno's Superb Website:
Problems with
radiometric dating techniques are greatly overstated by most young-Earth
advocates. They often cite isolated instances of implausible dates,
but these are generally caused by obsolete dating methods, contamination
that a good scientist would detect (and which does not affect the
large majority of dates), or by attempting to date materials that
are younger than the dating method's margin of error (using radiometric
methods to date recent Hawaiian lavas or living sea creatures, for
example, is akin to using an unmarked yard-long stick to measure
the thickness of a human hair). Most modern radiometric dating uses
the isochron method, which measures several different samples (and
sometimes different decay paths) and correlates them. The isochron
method basically cross-checks itself constantly, and results that
do not represent real ages will fail the isochron tests. Consequently,
the isochron method does not require any assumption about initial
amounts of parent and daughter elements (a common young-Earth objection
to radiometric dating). An important consideration with the isochron
method, however, is to know what it is that you're dating. Plotting
several samples on an isochron will tell you how long ago the samples
were separated from one another. For samples from the same lava
flow, this will give you the age of the lava flow. But for samples
from different flows, there can be a residual isochron giving the
age of the melting event in the Earth's mantle from which the flows
were derived. This is exactly what ICR geologist Steve Austin measured
in the Grand Canyon. He claims that Rb/Sr isochron dating of lavas
at the top of the Grand Canyon gives ages older than Grand Canyon
basement rocks (ICR Impact #224, http://www.icr.org/pubs/imp/imp-224.htm).
However, since Austin's samples came from several different flows,
he could not have been dating the age of a single flow, rather he
was dating the magma chamber beneath the Grand Canyon, from which
all of the flows came. Although Austin claims that his "anomalous
ages" cast doubt on radiometric dating in general, the fact
is that geochemists often use the same method Austin used to date
melting events much earlier than the formation of the flows themselves.
For a more detailed discussion of ICR's "Grand Canyon Dating
Project," see Stassen (1999),
http://www.talkorigins.org/faqs/icr-science.html. Another common
objection to radiometric dating is that addition or removal of parent
or daughter elements may have occurred. However, in most cases this
would leave tell-tale chemical clues that scientists could detect
(and indeed this frequently happens), and furthermore such contamination
could not possibly account for all of the world's radiometric measurements,
which are in good agreement. Finally, radioactive decay rates are
known to be constant under all relevant physical conditions. The
fact is that, although radiometric dating is imperfect like any
other science, there is tremendous overall agreement among radiometric
ages, as well as with stratigraphic (relative) ages, giving very
strong circumstantial evidence for the reliability of radiometric
dating methods. For a general overview of radiometric dating, see
Radiometric Dating: A Christian Perspective by Christian geologist
Roger Wiens (http://asa.calvin.edu/ASA/resources/Wiens.html).
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