1. Potential for aquifer compaction, land subsidence, and earth fissures in the Avra Valley, Pima and Pinal counties, Arizona Yale Public content 1989. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; For sale by Map Distribution. English. Public. Arizona, Pima County, and Pinal County.