Volltext Seite (XML)
CONTENTS. xiii Application op Geological facts and pkinciples, to the business of MINING, 123 Fissures formed by the cooling of the earth’s crust, 127 Drainage fissures, and Galleries of sublimation, and filling of veins, .... 129 Continuity and persistence of veins in depth, 130 Character of a vein illustrated, 133 Structure of mineral veins, I34 Indications of a good or poor vein, 136 Changes which a vein undergoes near the surface 139 Veins of Magnetic and Specular iron,. * 139 their phenomena, 145-54 Limonite and Bog ore, 154-5 Gold bearing rocks, , 155 Changes in the veins of, 15g Origin of native gold and its Geological relations I59 Comparative richness of the upper and lower parts of a vein, 161 Direction of Auriferous veins, 62 Veins passing vertically from one rock to another, 162 Age of Auriferous veins of North Carolina, 163 Age of gold bearing rocks, 754 Distribution and extent of Auriferous veins, igg Pyritous and Auriferous copper lodes, igg Structure of the Congdon Copper lode, Ducktown, Tennessee, 165 Copper mines of Lake Superior, 777 Disseminated native copper in Hornblende, 173 Vitreous or Gray Copper, 774 Lead bearing rocks of the United States 174 Limits of the veins of lead bearing Strata, 179 Position of the Ore and least thickness of a vein which can be worked with profit, , igQ Indications of a vein beneath, _ _ 737 Extent of the lead bearing rocks of the West, igi Lead and Zinc of New York, Massachusetts and Connecticut, 182 Expenses attending mining operations, 183 Value of mining property, 7gg Statistics and Dynamics of Geology, Conclusion, 191—3