Beware of paleoenvironmental deductions
by Michael J. Oard
Map of the United States showing the Permian red beds and evaporites, which were
interpreted as an ancient lake of strong and concentrated acid! (after Benison et
al.1)
As a reader of the geological literature, I am amazed by the paleoenvironmental
interpretations that are often made. Rarely do the researchers qualify their interpretations
with “possibly”, “maybe”, or other such words to indicate
uncertainty. We read, for example, that a particular conglomerate was laid down
by a stream, or a such-and-such siltstone was deposited by oscillating tides.
Sometimes they will even tell you what the climate was like millions of years ago
when formation X was laid down. These paleoenvironmental deductions use the uniformitarian
assumption and are usually based on the type and character of the formation and
the particular fossils contained in the rock. Here is one such statement about a
Permian evaporite formation in the North American mid-continent deposited over an
estimate area of 200,000 km2:
“They were deposited in non-marine saline lakes, pans and mud-flats, settings
that are typically assumed to have been alkaline.”1
Usually these evaporates would automatically be assumed to have been deposited in
non-marine saline lakes, pads and mud-flats. They would have simply stated that
the environment was alkaline, except for a rather shocking new discovery, which
sheds light on the value of such paleoenvironmental deductions as well as on the
uniformitarian assumption.
The researchers analyzed fluid inclusions within halite from the evaporate formation.2
These inclusions provide information on the properties of the fluid which the ‘evaporite’
precipitated. The analysis revealed that the formation was deposited in an extremely
acid environment with a pH less than 1. Saline lakes are normally alkaline,
so discovering such acidity should cause researchers to ask whether the formation
was really laid down in saline lakes, pans and mud-flats. But not bashful about
other paleoenvironmental interpretations, the researchers now state that the evaporites
were deposited in the same environment over a 200,000 km2 area in very
acidic lakes. Furthermore, the ‘paleolakes’ were shallow, based on salt
crusts and desiccation cracks. ‘Root features’ also are found in this
highly acidic paleoenvironment. The best modern analog the researchers could find
is a series of natural acid lakes in southern Australia with a pH ranging from 2
to 4—much higher than suggested for the Permian formation.
It is interesting how the addition of just one variable can upset so much previous
environmental interpretation
It is interesting how the addition of just one variable can upset so much previous
environmental interpretation. Although they can find a poor comparison in southern
Australia, a highly acidic lake and groundwater over such a large area defies uniformitarianism
and should cause the researchers to question their basic assumptions. The authors
do suggest that paleoenvironmental interpretations should be checked more closely.
For creationists, this report warns us about paleoenvironmental interpretations.3 Some of these interpretations
may be okay. However, many are simply an outgrowth of uniformitarianism, and the
modern analogs they employ are often poor. Paleoenvironmental interpretations need
to be checked properly within the creationist Flood paradigm. After all, the Flood
was unique in earth history. Deductions based on uniformitarianism are fraught with
error.
If the highly acidic fluid inclusions in the evaporites represent the pH of the
water during the flood in this area when the formation was precipitated, it indicates
that some, if not all, Flood depositional environments were unique. What could cause
such a highly acidic environment over such a large are during the Flood? There is
work to be done by creationist chemists.
Related articles
References
- Benison, K.C., Goldstein, R.H., Wopenka, B., Barruss, R.C.
and Pasteris, J.D., Extremely acid Permian lakes and ground waters in North America,
Nature 392(6679):911, 1998. Return to text.
- Benison et al., ref. 1, pp. 911–914.
Return to text.
- Froede Jr, C.R., Field Studies in Catastrophic Geology,
Creation Research Society Technical Monograph 7, Chino Valley, Arizona, pp. 7–13,
1998. Return to text.
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