TL te 

244 STRUCTURAL AND FIELD GEOLOGY 

rarely two fissures intersecting at right angles have received 
their mineral contents at the same time (see Fig. 96). 

FIG. 96.—CONTEMPORANEOUS CROSS-VEINS. (Plan). 
Heaving of Lodes.—When the intersecting lode occupies 
a fissure of displacement or true fault, it invariably shifts or 

FIG. 97.—HEAVING OF ONE VEIN BY 
ANOTHER. 
heaves the lode it traverses 
(see Fig. 97). If the faulitee 
normal, then the older lode 
is shifted in the direction of 
the downthrow; in the case 
of a reversed fault the older 
lode will, of course, be heaved 
in the opposite direction. 
Contents of Fissure 
Veins.—These are known as 
veinstone, vernstuff, matrix, Or 
gangue, and consist largely of 
crystallised minerals, such as 
quartz, calcite, and other car- 
bonates (dolomite, magnesite, 
etc.), barytes, and fluor-spar. 
Fragments of the “country” (ze. the rocks traversed by a 
lode) frequently appear, and often constitute the larger 

