U.S. Geological Survey Professional Paper, Issue 1640

area of ultramafic AVERY AVERY AVERY base rate basin Climax porphyry molybdenum Climax-type Colorado mineral belt consistent Cyprus massive sulfide densities for 13 deposit per square deposits in Nevada deposits per unit deposits Singer descriptive model esti estimate the number estimated number GLOBAL MINERAL RESOURCE grade and tonnage Hokuroku district kimberlite kmē known deposits known porphyry copper kuroko deposits kuroko massive sulfide Laramide orogeny mafic massive sulfide deposits mineral deposit density mineral deposit model mineral resource assessments normal distribution number of deposits number of podiform number of undiscovered numerical-statistical estimates ophiolite percent permissive area Permissive rock permissive tracts Pillow Lavas Piotang placer gold deposits pluton podiform chromite deposits porphyry copper deposits porphyry molybdenum deposit quartz vein deposits rate of occurrence regression Singer and Mosier square kilometer tonnage model Singer type this report U.S. Geological Survey ultramafic rock undiscovered deposits USGS Volcanic rocks volcanogenic manganese deposits well-explored Wolframite Xihuashan