
CONTENTS xiii 
CHAP PER XX 
GEOLOGICAL SURVEYING—continued 
PAGE 
Forms of Outcrop. Measurement of Thickness of Strata. Thicken- 
ing and Thinning of Stratas Unconformity. Overlap. 
Normal Faults. Reversed Faults. Eruptive Rocks and 
Contact Metamorphism. Regional Metamorphism. Archzean 
Gneissose Rocks . : s : ; : 291-306 
CHAPTER “XX 
GEOLOGICAL SURVEYING—continued 
Mapping of Unconsolidated Tertiary Deposits, and of Glacial 
and Fluvio-glacial Accumulations—Boulder-clay; Roches 
Moutonnées ; Terminal Moraines, etc. Raised Beaches. 
Lacustrine and Fluviatile Deposits. Peat : : 307-320 
CHAPTER XXI 
GEOLOGICAL MAPS AND SECTIONS 
Geological Maps and Explanatory Memoirs. Geological Sections 
—Horizontal Sections should show both the Form of the 
Ground and the Geological Structure ; Direction in which 
such Sections should be drawn ; Method of plotting a Section 
ona True Scale. Vertical Sections. : , 321-329 
CIrAPrER XXII 
ECONOMIC ASPECTS OF GEOLOGICAL STRUCTURE 
The Search for Coal—Conditions under which Coal occurs. Trial 
Borings. The Search for Ores—General Considerations 
which should guide the Prospector ; Nature of the Evidence. 
Geological Structure and Engineering Operations—Excava- 
tions, Tunnels, Foundations : : : ; 330-346 
CHAPTER XXII 
ECONOMIC ASPECTS OF GEOLOGICAL STRUCTURE— 
continued 
Water-supply. Lakes and Impounded Streams. Reservoirs. 
Supply from Rivers. Underground Water—the Water-level ; 
Natural Springs as illustrating the course followed by Sub- 
terranean Water ; Surfaceand Deep-seated Springs. Common 
Wells and Driven Wells. Artesian Wells. Considerations 
to be kept in view in the search for an Artesian Water-supply. 
Drainage. Distribution of Disease in relation to Geological 
Conditions , : : : ; : 347-367 
