The Granite Basin laccolith is located in the Mescal Mountains of the San Carlos Indian Reservation, 15 miles ENE of Kearny, Arizona. According to Willden (1964), the feldspar-mica porphyry intruded the Naco Limestone about 62 Ma. Locally, the Pennsylvanian Naco strikes northwesterly and dips about 25 to 30 degrees to the southwest. At the southeastern end of the laccolith, the Naco Limestone is nearly vertical and strikes to the northeast.
America’s infrastructure is built of sand, gravel, and crushed rock; collectively referred to as aggregate. And that is the topic of our 45th episode of the Arizona Mining Review - an interview with Eric Mears on gravel production and consumption in the Phoenix Metro area.
For 85 years, ending in 1996, the US Bureau of Mines (USBM) drafted and released 1000s of seminal reports on mineral resources and mining technology in the United States. The contents of those reports still have value. Unfortunately, access to USBM reports frequently proves difficult.