CONTENTS
PART I
[INTRODUCTION
CHAPTER I
PAGE
THE Score or EcoNoMic GeoLogy AND THE SEARCH FOR ORES 1
Definitions of Mineral, Ore-grade, and Metal, The Sporadic Dis.
tribution of Ores, Prospecting, Structure of Lodes. The
term Reef,
CHAPTER II
THE FORMATION OF DEPOSITS OF USEFUL MINERALS ® .
History of Study of Ores. Structure of the Earth ; its Barysphere.
Source of the Metals in Ores. Ore Formation in Relation to
Igneous Rocks. The Ore Zone, Plutonic, Juvenile, and
Magmatic Waters. Magmatic Ores. Lode Deposition—Hyda-
togenesis, Propylitization, and Pneumatolysis. Lode Structure
and Depth of Ore Formation. Ore Sequence in Depth. Ore
Shoots and Ore-bodies. Efflorescent Minerals. Bedded
Mineral Deposits. Alluvial Ores and Placers. Microscopic
Study of Ores. Chief Mineral Deposits due to Segregation,
PART II
ORE DEPOSITS
CHAPTER IIT
ORES OF GoLD . . .
Gold and its Qualities. Gold in Sea-water, Gold Lodes and Ig-
neous Rocks. Classification of Gold Ores— Primary Ores.
Gold-quartz Fissure Lodes, California, Ballarat, Mysore,
Volcanic Fields—Rocky Mountains and New Zealand. Pneu-
matolytic Ores—Cripple Greek and Passagem, Brazil. Iso.
lated Gold-quartz Veins—Saddle- and Ladder-lodes. Im-
pregnations and Replacements — Rhodesia, Homestake,
Alaska, and Porcupine. The Goldfields of West Australia.
Secondary Ores—Mount Morgan, Queensland, Alluvial
Goldfields—Placers ; Deep Leads, The Rand Banket.
Morro Velho.
2