Origins 19(1):44-48 (1992).
In the region of the Kodachrome Basin State Park, Utah, are found some unusual vertically oriented, intrusive sedimentary structures. They are called pipes if cylindrical in shape (see Figure 1 and cover photo), or dikes if flat-like in shape. These structures, which sometimes reach heights well over 50 m (150'), have come from the sedimentary layers below. In the same area, there is also indication of collapse of some sediments into lower layers (Christiansen 1952).
FIGURE 1. One of the largest exposed "pipes" in Kodachrome Basin. The surrounding rock, which is softer, has been eroded away, leaving this 50 m (150') "monolith." The surface of the pipe is badly eroded.
These features in the Jurassic layers raise interesting questions
regarding the amount of time involved in their formation. The source layers would have to
be soft in order to intrude into other layers. Sediments cannot remain soft forever; they
tend to become cemented. Cementation occurs when dissolved minerals are carried by water
into the sediments, hardening them into rocks. Some other features of these pipes also
suggest that there was not much time between deposition of these layers and recent
(Plio-Pleistocene) geologic activity. The conundrum is that the standard geologic time
scale implies well over 150 million years between laying down of these sediments and what
appears to be the time of intrusion.
The details of these strata, which are about 600 m (2000') thick,
have been worked out by Thompson and Stokes (1970) (see Figure 2). The Jurassic layers
involved have a putative age of 144-208 million years. The Carmel Formation of this group
averages around 179 million years, and the Entrada averages around 166 million years. In
parts of the area an unnamed Plio-Pleistocene channel and sheet conglomerate (Gregory
1951) covers various formations. It contains basalt pebbles considered to be only 1-6
million years old, and therefore is interpreted to be much younger than the main Jurassic
sedimentary formations of the area.
FIGURE 2. Diagrammatic representation of a section through the pipe and dike-bearing strata in Kodachrome Basin. Legend for formations: Tr/Jn — Triassic-Jurassic Navajo; Jcj — Jurassic Carmel, Judd Hollow; Jpt — Jurassic Page Sandstone, Thousand Pockets Tongue; Jcp — Jurassic Carmel, Parla River Member; Jcw — Jurassic Carmel, Winsor Member; Jcww — Jurassic Carmel, Wiggler Wash Member; Jeg — Jurassic Entrada, Gunsight Butte Member; Jec — Jurassic Entrada, Cannonville Member; Jee — Jurassic Entrada, Escalante Member; Jh — Jurassic Henrieville Formation; Kdt — Cretaceous Dakota-Tropic Formations undifferentiated.
Hornbacher (1984) has mapped and described 67 pipes and many dikes
in the area. They are found at various stratigraphic levels, but dominate in the Gunsight
Butte member of the Entrada (Figure 2). One intrudes as far up as the Escalante member of
the Entrada. The pipes range up to 52 m (170') in exposed height and up to 15 m
(50') in diameter. Analysis of the rocks and minerals in the pipes shows similarity,
mainly to the upper Paria River and lower Winsor Formations below. They are the most
likely source for most of the pipes. Some upper Winsor and Thousand Pockets Tongue of the
Page Sandstone (see Figure 2) and possibly other layers have occasionally also served as
source for the pipes.
The mechanism for intrusion is problematic and may never be known.
Hannum (1980) has suggested that the pipes came from cold springs. Hornbacher (1984)
favors seismically induced sediment liquefaction and intrusion. The relatively smooth and
striated wall pattern of some pipes (Figure 3) favors the latter interpretation. To add to
the mystery, there seems to be little or no disturbance of bedding planes or indication of
compressive strain in the sediments surrounding the pipes. This suggests that both the
pipe material and the surrounding sediments were soft when the pipes formed.
FIGURE 3. Closeup view of the surface of one of the pipes showing vertically oriented striations. The slightly darker vertical rock wedge to the right is not part of the pipe but a remnant of the surrounding "rock" into which the pipe intruded.
Hornbacher (1984) gives evidence that intrusion took place at the
time of the recent Plio-Pleistocene conglomerate deposition. This includes: 1) intimate
association of the Plio-Pleistocene conglomerate with the top of one pipe; 2) fluid escape
structures from this pipe into the conglomerate; and 3) the Plio-Pleistocene tectonic
activities in the region (i.e., earthquakes, orogenies) needed for the suggested mechanism
of intrusion. LeFevre et al. (1987) suggest a Jurassic age for formation of the pipes, but
give no direct supportive evidence.
These pipes appear to present a problem for the standard geologic time
scale, since it would require that the Jurassic formations which serve as source for the
intrusions remain soft (uncemented by minerals) for over 150 million years. Considering
how easily cementing minerals are transported through sediments by water, this seems
highly unlikely. It also seems highly unlikely that a delithification process (dissolving
of cement) would take place at the same time throughout the thick and highly varied
sequence over the widespread area in which these pipes are found.
Even if one does not take into consideration the evidence for a
Plio-Pleistocene intrusion, there is still a problem for the standard geologic time scale.
The time, represented by the vertical distance between the source of the pipes and their
present location, would be many millions of years (13 million if you use the average
Carmel and Entrada ages). It seems very unlikely that the source material could remain
uncemented for that length of time. Some of the pipes intrude 100 m (300') of
sediment.
One can argue that since there are now soft sediments on the ocean
floor which are assumed to be many millions of years old, the sediments producing the
pipes and the surrounding rocks could have likewise remained soft for many millions of
years. However, the situation associated with these pipes does not appear to be
comparable. Some of the layers associated with the pipes are interpreted as being
terrestrial instead of marine. We do not now see in the continental crust older layers in
a fluid state that could form the pipes. Associated with these pipes and dikes are long
fine veins originating from the pipes and penetrating the surrounding layers. These seem
to mandate a highly fluid source (i.e., the pipes themselves). However, it seems virtually
impossible for the intruding material in these veins to have remained soft for any
extended period of time. An overburden of more than 1200 m (4000') of sediment once
covered the now-exposed area where these pipes are found. This overburden would create a
pressure of 275×105 Pascals (4000 lb/in2). Such pressure would
induce rapid cementation, precluding a Plio-Pleistocene intrusion.
These pipes are fascinating structures. The model of formation that
seems to best fit the data would be rapid deposition during the recent Genesis flood, with
subsequent seismic activity liquefying uncemented sediments which would then intrude into
the overlying soft sediments, forming the pipes and dikes.
REFERENCES
COVER. View of a clastic "pipe" in Kodachrome Basin
State Park in southwestern Utah, U.S.A. The origin of these pipes has been an enigma. For
further discussion, see the General Science Note in this issue. Photo taken by Ariel A.
Roth.
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Geoscience Research Institute. All rights reserved.
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