Bulletin, Ausgaben 954-955

15 meters 30 meters 40 percent adit average Baja California basin bedrock beds black calcite body braunite breccia calcite Camagüey centimeters Chihuahua Cía Coahuila consists contains Creek crystals depth Durango east explored fault feet Fissure deposit fluorspar fracture Gavilán Geol Geological Survey gneiss gold grade granite Guadalupana Gulch hills inches kilometers lenses limestone Lucifer manganese content manganese deposits manganese oxides meters meters long meters thick meters wide Metric tons Mexico Minas mined Montaña de Manganeso moraine northeast northwest occur optical calcite outwash Parral percent of manganese percent of silica phosphate phosphate rock places plate probably production prospecting psilomelane quartz reserves rhyolite road samples San Antonio San Luis Potosí schist shaft shale silica Sonora South Platte southeast southwest strike structure surface Tarryall Tarryall Creek terrace tion trend tuff upper valley vein zone veinlets vertical Veta width Zacatecas