Geology
The Preserve is wholly within the Flint Hills physiographic
province. The Flint Hills have been formed by the erosion of a belt of resistant
limestone and softer shale and sandstone that includes 40 separate formations
and measures 3,000 feet (915 meters) in total thickness (Jones 1998). The
highest elevations exceed 1,600 feet (500 meters) and the lowest are 1,150 feet
(350 meters) in the Cottonwood River valleys.
Minerals
A 12-mile (20-km) wide uplift that extends through the
Preserve dominates the petroleum geology of Chase County. According to Carr,
this uplift is the most important feature in both structural and stratigraphic
trapping of oil and gas in Chase County. The Preserve and surrounding area have
a history of mineral activities (gas production) since 1929 (Carr 1998). Neither
NPT (the surface landowner) nor the NPS owns or controls the current mineral
interests. These were retained by Boatman’s Bank (Trustee), now Bank of
America, when the property was purchased by NPT. The bank reserved all oil, gas,
and other minerals of any kind whether a liquid, solid, or gas hydrocarbon or
non-hydrocarbon lying more than 200 feet (61 meters) below the surface, for a
period of 35 years beginning June 4, 1994. The Trustee will not conduct
exploration within 220 yards (201 meters) of the main house and barn, and will
not engage in any commercial hard rock mining, surface mining, strip-mining,
coal mining, or quarrying. The Trustee has assigned oil and gas exploration
working interest to Chisholm Resources, Inc.
Presently, gas production on the Preserve is from very shallow reservoirs (200-400 feet; 61-122 meters) and is of a low pressure and a low flow rate (Carr 1998). While it is generally agreed that these shallow reservoirs have additional potential, the characteristics of the gas produced may make production uneconomical (Carr 1998, National Park Service 1999). Potential production from deeper formations within the Preserve would have to come from poorly defined strata and would be highly unlikely or speculative at best (Carr 1998, National Park Service 1999).
According to Carr, a total of 47 gas wells have been drilled on the Preserve: 22 have been plugged and abandoned, and 25 remain shut-in, non-productive (National Park Service 1999). In addition to the shut-in gas wells, surface production equipment including well flowlines, field gathering lines, and meter runs exist on the Preserve. Associated with these operations are soil contamination, resulting in the loss of vegetation cover; actively eroding creek banks; and a lack of adequate signage and fencing to ensure resource protection (National Park Service 1999).
Soils
Several soil associations are identified within Chase County
but no site specific soil survey has been completed for the Preserve. Soils are
derived from limestones, sandstones, and shales. The soils may be relatively
deep in the bottoms of the larger stream valleys, but are typically thin on the
flanks and tops of the hills themselves; bedrock exposures are visible
throughout the region (Jones 1998). The soils are excessively drained, and
runoff is rapid with slopes ranging from 30-50% found on the Preserve (see
Figure 9).