

CRAP Wika 2X) 
GEOLOGICAL MAPS AND SECTIONS 
Geological Maps and Explanatory Memoirs. Geological Sections— 
Horizontal or Profile 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 on a True 
Scale. Vertical Sections. 
Geological Maps and Explanatory Memoirs.—The accom- 
panying maps (Plates LV., LVI.) will serve to illustrate the 
method of tracing geological lines, some account of which 
has been given in the two preceding chapters. In Plate LV. 
only the actual rock-exposures seen by the geologist are 
represented. These are indicated by the arrows and con- 
tinuous lines, the patches of colour showing the extent of the 
areas where rocks come to the surface. Plate LVI. repre- 
sents the same region with the several boundary-lines, etc., 
completed. The direct and indirect evidence which guides 
the observer in carrying outcrops, faults, etc., from one point 
to another, must no doubt be of unequal value. In some 
places it may be so convincing that one may almost feel 
justified in representing outcrops, etc., by means of continuous 
ies, while in other places it may beso slight that the 
boundaries laid down upon the map can be only an 
approximation to the truth, and should, therefore, be indicated 
by dotted or interrupted lines. A glance at the maps will 
show that the geological structure of the region represented 
is so devoid of complexity and the evidence so full, that the 
observer could hardly go far astray in carrying lines across 
such a country. The maps are merely diagrams, however, 
designed to bring into one view certain leading structures and 
the oe of tracing these, and therefore it must not be 
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