arches in rock fins.
4 There must be
some factor that locally enhances
the effects of erosion within a
rather small part of a rock fin to
produce an arch. How erosion is
localized within a rock fin to form
an arch is enigmatic.”5
A new speculative hypothesis
A new hypothesis proposes that
arches and other sandstone landforms
are formed by differential stress that
locks the sand grains during erosion.
The researchers submerged 10 cm
cubes of sand with weights on top. As
erosion occurred, differential vertical
stress caused the locking of sand
grains that resisted further erosion.
In nature the eroding agent can be
wind or water.
Unfortunately, the experiments
really do not apply all that well to
natural arches. The researchers used
unique sand from a quarry in the
Czech Republic that has angular sand
grains. It is the angular sand grains
that can especially be locked when
the vertical stress increases due to
differential erosion. Moreover, in
order to form an arch, the researchers
had to start with a cut at the base of the
sandstone block. They assume natural
sandstone has a planar discontinuity
that would weather faster. So, it
appears a little arch had to form
first before differential stress would
increase its size and preserve it.
These experiments, along with
their numerical analyses, are artificial.
Arches National Park is a good
location to test this new hypothesis. It
has over 2,000 arches that are mostly
developed in the Entrada Sandstone.
The vast majority of the arches in
Arches National Park are made of
fairly homogenous sandstone that
is considered to be lithified desert
sand. The sand grains are generally
rounded. It is unlikely that spherical
sand grains would lock enough to
cause differential erosion even under
A possible Flood mechanism
Large free-standing arches in
sandstone are not forming today, but
are being destroyed. It does not seem
possible that they were formed by
present processes. The only possibility
appears to be quick formation during a
rapid erosion event. The final draining
of floodwater during the Recessional
Stage of the Flood9 would cause the
rapid erosion. Reconstructing exactly
Figure 1. Landscape Arch, Arches National Park, Utah, USA
how any one free-standing arch
formed may be extremely difficult,
or even impossible, but it is possible
that turbulent eddies or cavitation first
eroded the joints into fins followed
by greater erosion at the base of a fin,
which rapidly carved an arch
2. Harris, A.G., Tuttle, E. and Tuttle, S.D., Geology
of National Parks, 5th edn, Kendall/Hunt
Publishing, Dubuque, IA, p. 83, 1990.
3. Oard, M.J., Many arches and natural bridges likely
from the Flood, J. Creation
23( 1): 115–118, 2009.
4. A rock fin is a narrow, strip of rock with a
vertical wall produced from the weathering
and erosion of joints and expansion cracks in
5. Cruikshank, K.M. and Aydin, A., Role of
fracture localization in arch formation, Arches
National Park, UT, GSA Bulletin 106:879–891,
1994; p. 879.
6. Bruthans, J., Soukup, J., Vaculikova, J. et
al., Sandstone landforms shaped by negative
feedback between stress and erosion, Nature
Geoscience 7:597–601, 2014.
7. Paola, C., Emergent sculpture, Nature Geoscience 7:552–553, 2014.
8. Arches National Park, www.desertusa.com/
arches/ du_arc_desc.html, accessed 4 July 2016.
9. Walker, T., A biblical geological model; in:
Walsh, R.E. (Ed.), Proceedings of the Third
International Conference on Creationism,
technical symposium sessions, Creation Science
Fellowship, Pittsburgh, PA, pp. 581–592, 1994.