Maxwelton Sink Cave

Research Abstract
Maxwelton Sink Cave is a 9.6 mile long mapped cave in Greenbrier County near Lewisburg. This cave was first partially opened to cavers by flood waters from Hurricane Camille in 1969, but has been closed since Hurricane Agnes flooding of 1972. Its former entrance is situated at the downstream end of a spectacular karst blind valley containing Cove Creek. This study involved efforts to open a new entrance to this cave on property of Dave Scott, through microgravity geophysical surveying and digging, and is part of Jeff Bray’s M.S. geology thesis at West Virginia University.

In 2001 Dave’s surveying located the Heaven passage of Maxwelton Sink Cave relative to his property. Jeff, Dave, and others surveyed five parallel traverse lines and did microgravity surveys in 2001 and 2002. Two Scintrex microgravity meters were used, one from Nicholas Crawford of the Center for Cave and Karst Research, the other from Maxwelton GeoSolutions, Ltd. Gravity data were analyzed with aid of the above Center and a software package distributed by Geotools of Laughing Rock Software. Gravity surveys produced three 30-microgal anomalies over Maxwelton Sink Cave. A borehole was then drilled over these anomalies, intercepting two cave passages, 30 feet and 105 feet deep. These passages are about 10 by 8 feet in cross section, based on a camera borehole survey. The lower passage, Heaven passage of Maxwelton Sink Cave, was then traced 150 feet farther south to a sinkhole as two 20-microgal anomalies along two more gravity survey lines. A trackhoe and bulldozer were then hired to dig a pit 38 feet deep between the two anomalies, to intercept and open the Heaven passage with some microblasting. This research indicates that microgravity surveys are capable of detecting moderate sized cave passages over 100 feet deep.