A uniformitarian paleo-environmental dilemma at Clarkia, Idaho, USA
by Michael J. Oard
A farmer digging a snowmobile course accidentally unearthed one of the most remarkably-preserved
plant fossil localities in the world.1
The site is situated outside the small town of Clarkia in northern Idaho, about
60 km northeast of Moscow, Idaho, USA. One hundred and thirty species of plants
are represented, many typical of a warm-temperate to subtropical environment, such
as avocado, magnolia, and sycamore.
Leaves and fish
It is suggested that the fossils formed in a Miocene lake, dammed in the St Maries
River Valley when the Columbia River basalts erupted to the west. The northern
Rocky Mountains, USA, are postulated to have been a terrestrial environment during
the Tertiary. The idea of leaves falling into fine-grained lake clays appears
to be a reasonable paleoenvironmental deduction—at first glance. However,
such an interpretation is contradicted by a number of facts. There is even
evidence of marine catastrophic inundation.
The remarkable preservation of the leaves extends even to microscopic structures
within leaf cells that exhibit beautiful cellular detail. Just as interesting,
the original colour of the leaves has been preserved within the laminated
clays. The original green, brown, or red colours, suggestive of autumn, are
retained, which upon exposure promptly turn black.2
The fossils are preserved within laminated clay, interspersed with massive clay,
both containing ash beds that are barren of fossils.
Some investigators believe the laminated clays are varves and that each couplet
represents one year of seasonal deposition. However, Charles Smiley believes
the laminated clays represent storm rhythmites3—a
radical departure from the varve interpretation. Smiley’s deduction
seems more reasonable since there are also fish fossils within the rhythmites—one
a trophy-sized extinct trout. All the fish had their mouths open, as if they
died of anoxia. One would not expect such well preserved fish with little
or no sign of deterioration4 while
paper thin ‘varves’ were being deposited. The unusual condition
of the leaves and the fish fossils points to rapid deposition, not slow lacustrine
accumulation.
Furthermore, the leaves are not stacked one on top of another as expected with autumn
leaves dropping into a quiet lake. Instead, the leaves are separated
by sediments, an indication of very rapid deposition considering the degree of preservation
and the colour of the leaves.5
Many leaves even cut through several rhythmite layers with no physical damage, another
sign of rapid deposition.6
Marine environment
There are signs that the water was not fresh, as typical of most lakes, but marine
or brackish. For instance, abundant dinoflagellates, mysteriously all of one
species, have been identified.7
Dinoflagellates are normally considered marine. Hence, it is suggested that
fresh water dinoflagellates existed in the past. However, this freshwater
interpretation comes from other fossil localities that are assumed terrestrial,
just like the Clarkia beds.
Sponge spicules are also an abundant constituent of the rhythmites.7,8 Practically all sponges are marine. Apparently,
there are rare occurrences of freshwater sponges,8 and this latter is
the type chosen for the paleoenvironment of the Clarkia beds. It is interesting
that the sponges also suggest that the bottom water temperature was unusually warm
at 26–30°C,9 a paleoclimatic
enigma. Furthermore, the high temperatures suggested are not conducive to
the anoxic paleoenvironment needed to explain the excellent preservation.
Then there is an enigmatic diatom whose living analog is a marine-brackish
water taxon. However, even this diatom is said to include one ecological variety
that is only able to live in low salinity conditions.10,11 Of course, this latter variant
is the one assumed to have lived in ancient Lake Clarkia. Altogether, there
is an impressive amount of evidence that components from marine and terrestrial
environments have been mixed together.
Interestingly, some of the fauna are exotic to the northwestern United States.
The trophy trout is comparable to those living in southern Europe and Japan.12 The single dinoflagellate species is similar
to one known only from the Oligocene of China.13
Remember that this is supposed to be a Miocene lake. Much of the
flora is exotic to the northwest United States and is more typical of eastern Asia
or the southern Appalachians.14
Batten et al. state that the Clarkia fossils represent a unique distribution:
‘Most of the Clarkia plant taxa and many of the other organisms no longer
live together in western North America or in any other single biogeographic region.’14
All the warm climate elements suggest an environment unique to northern Idaho.
Conclusion
A superficial look at the Clarkia beds seems to support a typical uniformitarian
terrestrial lacustrine environment and uniformitarian scientists commonly make such
paleoenvironmental interpretations. However, the more one examines the details,
the more enigmatic their interpretation becomes.15
In the case of the Clarkia beds, the uniqueness of the fossils, the warm environmental
indicators, the exquisite preservation, and the indications of rapid deposition
contradict the simplistic uniformitarian deduction of a lacustrine environment.
The evidence supports an interpretation based on the global Flood recorded in the
Bible. The Flood is expected to occasionally mix organisms from terrestrial
and marine or brackish water environments. In addition, it is not a problem
for the Flood to deposit warmth-indicating taxa in middle and high latitudes.
And rapid deposition during the Flood is expected to produce well-preserved fossils.
Related articles
References and notes
- Clutter, T., The Clarkia Fossil Bowl, American Forests
91(2):22–25, 1985. Return to text.
- Smiley, C.J. and Rember, W.C., Physical setting of the Miocene
Clarkia fossil beds, northern Idaho; in: Smiley, C.J. (Ed.), Late Cenozoic History
of the Pacific Northwest—Interdisciplinary Studies on the Clarkia Fossil Beds
of Northern Idaho, Pacific Division of the American Association for the
Advancement of Science, San Francisco, pp. 11–31, 1985. Return to
text.
- Batten, D.J., Gray, J. and Harland,
R., Palaeoenvironmental significance of a monospecific assemblage of dinoflagellate
cysts from the Miocene Clarkia Beds, Idaho, USA,Palaeogeography, Palaeoclimatology,
Palaeoecology 153:162, 1999. Return to text.
- Smiley and Rember, Ref. 2, p. 17. Return to text.
- Smith, G.R. and Elder, R.L., Environmental interpretation of burial
and preservation of Clarkia fishes; in: Smiley, Ref. 2, pp. 90–91.
Return to text.
- Giannasi, D.E. and Niklas, K.J., The paleobiochemistry of fossil
angiosperm floras, Part I, Chemosystematic aspects; in: Smiley, Ref. 2, p. 164.
Return to text.
- Batten et al., Ref. 3, pp. 161–177.
Return to text.
- Williams, J.L., Spicular remains of freshwater sponges from a Miocene
lacustrine deposit in northern Idaho; in: Smiley, Ref. 2, pp. 349–355.
Return to text.
- Williams, Ref. 8, p. 350. Return to text.
- Batten et al., Ref. 3, p. 172. Return
to text.
- Bradbury, J.P., Dieterich, K.V. and Williams, J.L., Diatom flora
of the Miocene lake beds near Clarkia in northern Idaho; in: Smiley, Ref. 2, pp.
38–39. Return to text.
- Batten et al., Ref. 3, p. 171. Return
to text.
- Batten et al., Ref. 3, pp. 161–162.
Return to text.
- Batten et al., Ref. 3, p. 169. Return
to text.
- Oard, M.J., Beware of
paleoenvironmental deductions, Journal of Creation 13(2):13,
1999. Return to text.
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