Jerry H. Hassemer

• Caving basics
• Gravity survey in parts of Maricopa and Pinal Counties, Arizona
• Physical properties of rock samples from the Butte 1?□x 2 □quadrangle, Montana
• Physical properties of rock samples from the Butte 1ʻ́
• Principal facts and complete Bouguer gravity anomaly map for the west half of the Butte 1