Download PDF - Speleogenesis

96
NCKRI Special Paper No. 1
However, their distribution is clustered, with the density of
castiles within clusters reaching 18 features/km 2 . That
hypogenic speleogenesis is an ongoing process throughout
the region and capable of generating large sinkhole
development is exemplified by the Bottomless Lakes series
of sinkholes east of Roswell, New Mexico, or the Wink
Sink collapse on the eastern margin of the Delaware Basin,
Texas (see Figure 61 for their location).
Proper recognition of hypogenic transverse
speleogenesis gives a new perspective to such important
issues as assessment of sites of special concern, such as the
Waste Isolation Pilot Plant (WIPP) near Carlsbad, New
Mexico, or some nuclear power plants. The most karstspecific
studies for the WIPP area addressed the issue from
the perspective of epigenic karst concepts (Bachman,
1990; Hill, 2003b; Lorenz, 2006; Powers et al., 2006),
which leads to a misleading interpretation of observed
features when dealing with hypogenic karst. Recent
identification of the hypogenic origin for many caves in
the Rustler and Seven Rivers Formations (Stafford et al.,
2008) and interpretation of regional karst development in
the context of hypogenic transverse speleogenesis calls for
the need of a reassessment of karst hazard for the WIPP
site. Another example of special concern is the Neckar
nuclear power plant in Germany, situated in a river valley
above a multi-aquifer system containing a sulfate bed, with
ground deformation recorded in the immediate vicinity of
the plant and a major 60 m-deep collapse that occurred in
1964 a few kilometers away. An additional site of concern
is the Rovensky nuclear power plant in Ukraine, where old
and recent collapse and subsidence features were recorded
in the immediate vicinity, induced by hypogenic karst in
the confined Cretaceous chalk aquifer, a part of the
Volyno-Podol'sky artesian basin.
Figure 62. Distribution of breakdown structures in Zoloushka Cave
in plan (A, map fragment) and profile (B). 1 = cave passages; 2 =
passages destroyed by the quarry; 3 = isopachytes; 4 - 7 =
breakdown structures with the breakout cavities positioned at
various levels: 4 - at the bottom of the overlying aquifer, 5 - within
the confining clays, 6 - within the sandy-gravel bed, the upper
aquifer, 7 - within the loam bed; 8 = surface karst features; 9 = the
quarry faces (from Klimchouk and Andrejchuk, 2005).