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EFFECTS OF 
Besides cross veins, right running and quarterpoint veins, are (backs) 
or joints of the rock, which occasionally turn aside all the veins and 
always according to the law of the angles already explained. 
Dynamical relations of disturbed Strata. 
Dependence of direction on structure. — We may now consider the 
dependence of the great phenomena of dislocated strata on dynami- 
cal conditions and geological periods. It is already apparent that the 
direction of the joints of rocks is a phenomenon of more general oc- 
currence than the dislocations, dependent on more pervading and uni- 
form agency. The almost perfect constancy of their directions, amidst 
all the variations of the faults and breaks of a dislocated district, 
leaves no doubt of their independence of these ; but the correspon- 
dence observable in several instances of the direction of the disloca- 
tions and fissures opens a new view of the matter. The stratified 
masses, divided in their separate beds into characteristic structures, and 
traversed through whole formations by long and continuous fissures 
crossing in two principal directions, presented lines and points of least 
resistance, which would yield variously to the impulse of any suf- 
ficient pressure upon their planes. Such pressure, acting from below 
or from above, would necessarily break at least partially the continuity 
of the extended strata, by raising or depressing certain parts : if the 
principal mass of the strata displaced had very close joints or were 
imperfectly consolidated, (as laminated argillaceous rocks), they might 
be uplifted or depressed in great waves or small curved ridges and 
furrows, (the general character of the Ribblesdale system) : if the 
rocks were much divided by open joints, and generally consolidated, 
the displacements happening along the planes of least resistance would 
depend for their direction on the relations of the natural joints and 
fissures to the direction of the force. 
If a great force were supposed to be exerted against a small area , 
the effect would be a conical elevation or depression modified according 
to the influence of one or two systems of yielding fissures. One such 
system of yielding fissures would elongate the conical displacement 
