Loess problems
by Michael J. Oard
Loess, generally considered to be wind-blown silt, has caused a number of problems
for uniformitarism. The major problems are the missing periglacial loess from past
ice ages, a lack of a source for the immense volume of loess (covering about 10%
of Earth’s land surface) and the lack of eroded loess from past ice ages.
How loess is produced has also caused a quandary for uniformitarians, with only
fluvial tumbling in mixed-sized sediment producing a large volume of silt. However,
the Flood and post-Flood Ice Age provide a more plausible framework in which to
explain the volume and distribution of loess. Extreme turbulence in the Flood would
have provided the right context for producing the necessary silt, which may have
been reworked during the dry, deglacial phase of the Ice Age.
Figure 1. Burlingame Canyon rhythmites from one large Lake Missoula
flood at the peak of the Ice Age. Notice that only about one metre of wind-blown
silt was deposited on top of the sequence.
Loess is difficult to define, but it is generally considered to be wind-blown (eolian)
silt.1 It is composed mostly
of quartz grains, with minor portions of clay and sand often mixed with the silt.
Loess is commonly intermixed vertically with ‘paleosols’, which are
supposedly fossil soils that have been preserved in the geologic record or buried
deeply enough that it is no longer subject to soil forming processes.2 Scientists previously believed the silt particles
in loess were derived from ice abrasion, but they now believe that loess has both
a glacial and non-glacial origin.3–6
Loess covers much of the mid and high latitude continents, forming a thickening
belt in Europe from the Atlantic coast east into Russia and the Ukraine in areas
generally south of the Scandinavian Ice Sheet. It also covers a large portion of
the Midwest of the United States, the lowlands of Alaska, southeast Washington and
eastern Idaho7 and some
440,000 km2 of central China, where it is up to 300m thick.8 Millions of woolly mammoths and other Ice Age animals
are mostly entombed in loess in non-glaciated areas of Siberia, Alaska and the Yukon
Territory of Canada.9 Wind
blown material is common within the Ice Age portion of the Greenland ice cores.10
Despite the large number of studies, there are many problems associated with loess
from a uniformitarian view: ‘Few problems in Quaternary geology have raised
so much controversy as loess’.11
Missing loess
The most difficult uniformitarian problem is the ‘missing loess’. Practically
all periglacial loess is derived from the ‘last’ glaciation within the
uniformitarian multiple glaciation system, and specialists have tended to avoid
discussing the implications:
‘The periglacial loesses from China and elsewhere predominantly date from
the last Pleistocene glaciation: relatively few comparable occurrences are known
from earlier Quaternary glaciations … . A loess problem that is rarely touched
upon is the almost complete lack of loesses from ice ages before the last one’.12
The periglacial loess in China is different from the thick, extensive loess in central
China, which is considered non-glacial.13
Quaternary geologists once believed there were only four ice ages, but now they
claim there have been over thirty during the past 2.5 million years of geological
time, based on deep-sea cores.14
Where is the loess from all these previous supposed ice ages? The most straightforward
deduction is that there were no previous ice ages; there was only one Ice Age, which
was one of eleven reasons I listed in support of just one.15
Uniformitarian scientists have attempted to explain this missing loess in various
ways. The simplest explanation is that the loess was eroded by water and wind during
interglacial periods. The problem with this explanation is that the earth is currently
in an interglacial (the Holocene) and supposedly about ready to plunge into the
next ice age, according to the Milankovitch mechanism for multiple ice ages. If
it was eroded, the loess from the ‘last’ ice age has hardly been eroded
during the current interglacial, despite accelerated erosion caused by
deforestation and agriculture.16
As a result of this contradiction to the uniformitarian idea of multiple ice ages,
some scientists have simply suggested that the current interglacial is ‘different’
from all the previous interglacials. But such a special condition for the current
interglacial is difficult to imagine for some geologists,17 probably because such a suggestion defies the
very uniformitarian principle upon which current geological interpretation is based.
A recent hypothesis suggests that the loess from each ice age is simply ‘recycled’.18 According to this idea,
each ice age produces a little more loess than is lost during interglacials. So,
the amount of loess builds with time from the first glaciation to the thick loesses
of today.
It seems inconceivable that the entire amount of loess is reworked during each glaciation
so as to destroy evidence of loess from previous glaciations. Besides, the idea
is untestable and ad hoc. Since some of this
loess is trapped in river valleys, such as the Mississippi Valley, how would loess
be scoured out of these valleys and redeposited? There is also the problem that
each time the loess is recycled, why is it always recycled at the same
location and not spread all over the continents? Do strong ice age winds that would
rework loess only blow in the loess belt?
Lack of a source for loess
A second conundrum is the missing sources for loess. The amount of loess on the
continents is immense, greater than the volume of glacial till. It covers
10% of the earth’s land surface.19
Where and how did all this silt originate? The source and erosion of loess is difficult
to explain:
‘This leaves one well known question (where do the loesses come from?) and
one rarely (if ever) asked question: where did the eroded loesses go to?’17
One of the main problems for the origin of loess is that quartz in igneous and metamorphic
rocks has a mean grain size of approximately 700 μm, while the main size of detrital
quartz in 60 μm.20
The cutoff between sand and silt is 63 μm and most loess is in the range of 20
to 50 μm. So, the size of the quartz has to be reduced 90% from its source to
account for the formation of loess. How does this happen?
Four sources of loess have been proposed: (1) hot deserts, (2) cold deserts, (3)
drowned sources covered by late-glacial sea level rise and (4) glacial grinding.21 All these sources raise
questions. Hot and cold deserts do not produce significant quantities of loess.
There are problems associated with the origin of loess from continental shelves,
now underwater, since many loess belts are far inland from the sea.22
It had been assumed that the formation of loess was only by subglacial grinding.3
However, loess has been discovered in areas far from present or past glaciers or
ice sheets, such as in northern Tunisia, northern Nigeria, Israel and Saudi Arabia.23 Minor amounts of loess
have even been found in the Sahara Desert. Furthermore, experiments have shown that
glacial grinding does not produce much silt.3,5 This deduction
is reinforced by the observation that hardly any loess is produced by or deposited
in front of present-day glaciers.21 So, there does not appear to be a
viable source for the immense volume of loess.
Where is the eroded loess?
Loess is very young and fits in well with the young-earth timeframe and one Ice
Age.
A third problem is the lack of eroded loess. In the last quote above, an ignored
problem is the location of all the eroded loess over the several millions of years
allotted to multiple ice ages by uniformitarian scientists. Loess does not erode
easily, but when it starts, vertical erosion proceeds relatively fast.16
So, there should be a huge volume of eroded loess deposited somewhere if all these
glaciations were real. However, there is little of this reworked loess found on
the continents. Just like the missing loess, the supposedly eroded loess is also
missing. Furthermore, little of the loess, such as the Chinese loess, has been eroded.
The lack of erosion of current loess deposits and the failure to find several millions
of years of eroded loess strongly suggest that those millions of years are imaginary.
Loess is very young and fits in well with the young-earth timeframe and one Ice
Age.
How is loess produced?
Fourth, how is loess produced? There are now several other mechanisms besides glacial
grinding suggested for the formation of loess. These mechanisms include wind abrasion,
weathering, frost weathering, salt weathering and fluvial abrasion. However, experiments
in the formation of silt particles have demonstrated that these other mechanisms
are either ineffective or too slow, except for fluvial abrasion of mixed-size sediment:
‘The tumbling of sand alone in water resulted in very little comminution or
silt production … However, the addition of gravel-sized ceramic spheres to
simulate a mixed-size sediment load in a turbulent, high-energy fluvial environment,
produced rapid comminution and particle size reduction.’24
Based on a table of the amount of silt and the time needed to produce it, fluvial
tumbling with mixed-sized sediment rapidly produced a large volume of silt, while
wind abrasion was a distant second.25
Flood-Ice Age solution
How would the Flood, followed by a post-Flood Ice Age, explain the observations
of loess? There does not seem to be enough time in the Ice Age to generate so much
loess by glacial grinding or any other post-Flood mechanism. For instance, the monstrous
volume of non-glacial silt in the Chinese ‘loess’ cannot be accounted
for even within 2.6 million years of uniformitarian time:
‘The supply of immense quantities of quartz-dominated silt over the past 2.6
Ma for the Chinese loess plateau is indeed a very intriguing problem.’26
It is inconceivable that the sediments for the Chinese ‘loess’ can be
formed after the Flood.
A much better possibility for explaining the thick sources of ‘loess’
is extreme turbulence in the Flood, which would provide an ideal environment during
rock erosion for producing large volumes of silt.
A much better possibility for explaining the thick sources of ‘loess’
is extreme turbulence in the Flood, which would provide an ideal environment during
rock erosion for producing large volumes of silt. The Flood would act like a global
water abrasion mechanism, similar to the tumbler experiment of mixed-grain sizes
described above.
The Flood might also explain the origin of the particles that make up thick siltstone
and shale, which contains ~75% silt, observed in the rock record. The formation
of all this silt and its concentration in the rock record is a difficult uniformitarian
problem.27 One siltstone
formation in Africa averages 300 m thick.28
As the Floodwater drained, mud with much silt would have been deposited in ‘slackwater’
areas, which are areas with low current velocity late in the Flood. This mud could
be left on the surface after the Flood in various areas. For the Palouse silt, such
a slackwater area could have been created by the uplift of the Cascade Mountains
of western Washington and Oregon. Strong Ice Age winds would then rework the top
of the mud layers into true wind-blown deposits and spread real loess downstream
from sources.
The origin of most of the ‘loess’ from Flood abrasion is a rather radical
idea but seems to be the only possibility within the young-earth timeframe. There
is further evidence suggesting the original Flood generation of surficial silt deposits.
One of the reasons is that water seems to be involved in the transport process of
the silt at some stage:
‘Indeed, many loess-like deposits seem to have undergone some transport by
water and many such deposits accumulated in previous depressions even seem to have
formed by settling from suspension in shallow pools or lakes.’16
The action of water at some stage is reinforced by Wright:
‘Finally, a recent geochemical and isotopic study of loess deposits by Gallet
et al. (1998) revealed that all loess particles must have experienced at
least one cycle of aquatic transport.’27
The above quotes seem to suggest more than transport by glacial meltwater within
the uniformitarian paradigm. Gallet et al. further state that the geochemical
characteristics of loess are indistinguishable from shales, which favours a Flood
generation of ‘loess’.29
Figure 2. The rolling Palouse ‘loess’ of southeast
Washington. The rolling character is caused by the bulbous surface of the Columbia
River Basalts below the ‘loess’.
In studying the Lake Missoula flood,30
I noticed that since the peak of the Ice Age, only about a metre of wind-blown silt
was deposited on top of flood rhythmites in Burlingame Canyon of southeast Washington
(figure 1). This canyon is within the area of the deposition of the thick Palouse
‘loess’ that ranges in thickness from 2 to 75 m and covers an area greater
than 50,000 km2.31
Figure 2 shows a picture of the rolling Palouse silt. The rolling character is actually
derived from the underlying Columbia River Basalts.32 The early Ice Age should have been wet with the
formation of little loess, while deglaciation should have been much drier with great
amounts of wind blown silt. If all the Palouse ‘loess’ was formed by
dry winds during deglaciation, much more than a meter of silt should have been deposited
on these rhythmites.
Furthermore, sponge spicules have been found in the ‘loess’.33 Harold Coffin collected
sponge spicules, likely marine, at all nineteen locations sampled within
the Palouse ‘loess’ of southeast Washington.34 The lower layers of the Palouse silt are layered,
and rounded gravel is also found at some locations within the silt.33
This evidence suggests that the lower portions of many silt and sand deposits on
the surface of the earth likely were laid down in the very last moments of the Flood.
This material was subsequently reworked during the dry, deglacial phase of the Ice
Age. This reworking can explain the fact that loess contains some Ice Age mammals.
A further implication is that the Flood/post-Flood boundary is in the late Cenozoic
in the loess source areas, in particular in the early to mid Pleistocene, such as
in the Palouse ‘loess’ and probably in the Chinese loess. Such a boundary
was advocated by the late Roy Holt.35
Related articles
Further reading
Related resources
References
- Wright, J.S., ‘Desert’ loess versus ‘glacial’
loess: Quartz silt formation, source areas and sediment pathways in the formation
of loess deposits, Geomorphology 36:231, 2001.
Return to text.
- Klevberg, P., Oard, M.J. and Bandy, R., Are paleosols really
ancient soils? Creation Research Society Quarterly 40(3):134–149,
2003. Return to text.
- Wright, ref. 1, pp. 231–256. Return
to text.
- Muhs, D.R. and Bettis III, E.A., Geochemical variations in
Peoria loess of western Iowa indicate paleowinds of Midcontinental North America
during last glaciation, Quaternary Research 53:49–61,
2000. Return to text.
- Wright, J., Smith, B. and Whalley, B., Mechanisms of loess-sized
quartz silt production and their relative effectiveness: laboratory simulations,
Geomorphology 23:15–34, 1998. Return
to text.
- Smith, B. J., Wright, J. S. and Whalley, W. B., Sources of
non-glacial, loess-size quartz silt and the origins of ‘desert loess’,
Earth-Science Reviews 59:1–26, 2002.
Return to text.
- Busacca, A.J., Begét, J.E., Markewich, H.W., Muhs,
D.R., Lancaster, N. and Sweeney, M.R., Eolian sediments; in: Gillespie, A.R., Porter,
S.C. and Atwater, B.F., (Eds.), The Quaternary Period in the United States,
volume 1, Elsevier, New York, pp. 275–309, 2004. Return to
text.
- Kohfeld, K.E. and Harrison, S.P., Glacial-interglacial changes
in dust deposition on the Chinese Loess Plateau, Quaternary Science Reviews
22:1,859, 2003. Return to text.
- Oard, M.J., Frozen in Time: The Woolly Mammoth, the Ice
Age, and the Bible, Master Books, Green Forest, AR, 2004. Return
to text.
- Oard, M.J., The Frozen Record: Examining the Ice Core
History of the Greenland and Antarctic Ice Sheets, Institute for Creation Research,
El Cajon, CA, 2005. Return to text.
- Van Loon, A.J., Lost loesses, Earth-Science Reviews
74:309, 2006. Return to text.
- Van Loon, ref. 11, pp. 309, 310. Return
to text.
- Sun, J., Provenance of loess material and formation of loess
deposits on the Chinese Loess Plateau, Earth and Planetary Science Letters
203:845–859, 2002. Return to text.
- Kennett, J., Marine Geology, Prentice-Hall, Englewood
Cliffs, NJ, p. 747, 1982. Return to text.
- Oard, M.J., An Ice Age Caused by the Genesis Flood,
Institute for Creation Research, El Cajon, CA, p. 149, 1990. Return
to text.
- Van Loon, ref. 11, p. 313. Return to
text.
- Van Loon, ref. 11, p. 310. Return to
text.
- Van Loon, ref. 11, pp. 314–315.
Return to text.
- Wright et al., ref. 5, p. 16.
Return to text.
- Wright, ref. 1, p. 232. Return to text.
- Van Loon, ref. 11, pp. 309–316.
Return to text.
- Van Loon, ref. 11, p. 312. Return to
text.
- Wright, ref. 1, p. 233. Return to text.
- Wright et al., ref. 5, p. 25.
Return to text.
- Wright et al., ref. 5, p. 30.
Return to text.
- Gallet, S., Bor-ming, J., Lanoë, B.V.V., Dia, A. and
Rossello, E., Loess geochemistry and its implications for particle origin and composition
of the upper continental crust, Earth and Planetary Science Letters
156:158, 1998. Return to text.
- Wright, ref. 1, p. 234. Return to text.
- Nahon, D. and Trompette, R., Origin of siltstones:
glacial grinding versus weathering, Sedimentology 29:32,
1982. Return to text.
- Gallet et al., ref. 26, p. 169.
Return to text.
- Oard, M.J., The Missoula Flood Controversy and the Genesis
Flood, Creation Research Society Monograph Number 13, Creation Research Society,
Chino Valley, AZ, 2004. Return to text.
- Busacca et al., ref. 7, p. 294.
Return to text.
- Ringe, D., Sub-loess basalt topography in the Palouse Hills,
southeastern Washington, GSA Bulletin 81:3049–3060,
1970. Return to text.
- Lowry, W.D. and Baldwin, E.M., Late Cenozoic geology of the
Lower Columbia River Valley, Oregon and Washington, GSA Bulletin 63:12,
1962. Return to text.
- Coffin, H.G., The Miocene/Pleistocene contact in the Columbia
Basin: time implications, Origins 53:39–52, 2002.
Return to text.
- Holt, R.D., Evidence for a late
Cainozoic Flood/post-Flood boundary, Journal of Creation 10(1):128–167,
1996. Return to text.
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