JOINTED JEWEL: A STRUCTURAL ANALYSIS OF THE WORLD’S MOST COMPLEX CAVE SYSTEM

Jewel Cave is formed in the Mississippian Madison (Pahasapa) Limestone of the Black Hills of South Dakota and contains 200 miles of surveyed passages in under 4 square miles, making it one of the world’s most intricate and complicated multi-dimensional dissolutional maze caves and the third longest cave system in the world. Jewel Cave is best described as an angular network maze with several intersecting fracture controlled trends (Palmer et al., 2016). Barometric airflow studies conducted by (Conn, 1966; Wiles et al., 2009) reveal that explorers have discovered less than 3% of the cave. Due to the extensive nature of Jewel Cave, resource management efforts are focused on identifying how far and where the cave might extend, even before the remaining passages are discovered, so that Jewel Cave National Monument can begin formulating management strategies before any human impacts occur (Wiles, 2009).

The network outline of Jewel Cave is closely related to the stresses within the uplifting Black Hills during the early Tertiary Laramide orogeny (Palmer et al., 1989). Variations in stratigraphic facies of the Pahasapa Limestone result in joint systems in successive stories that display different frequencies and orientations (Ford, 1989). Since the structural nature of the Pahasapa Limestone is a primary control on cave passage morphology and orientation, quantifying structural controls on superimposed ascending joint systems can help to predict the location of new passageways. A partnership between the National Park Service and the Geoscientists In the Parks (GIP) program facilitated an internship study to map and quantify the Laramide deformation of the Pahasapa Limestone using a combination of field mapping techniques and ArcGIS to aid in exploration efforts and future monument boundary revisions.