571 
may be accompanied by faulting. Without faulting an extension of 
the geanticlinal axis is obtained by gaping fractures, i.e. by a 
movement normal to the fault-planes; with faults without gaping 
an extension is obtained by a movement parallel to faultplanes, 
which must be inclined to the geanticlinal axis. Shortening of the 
geanticline is possible by faulting along fault-planes that do not 
gape and which are not vertical to the geanticlinal axis. Similar 
relations prevail for a lengthening or a shortening of a section of 
the geanticlinal surface with a plane vertical to the geanticlinal axis. 
In the case of more or less free horizontal movement, a length- 
ening of the geanticlines will reveal itself near the surface through 
the formation of transverse or diagonal fractures, which may be 
gaping ov along which faulting may occur. Every position of the 
fault-planes is possible; besides by the direction and the velocity of 
the movement, the position of the fault-planes is also controlled by 
a great many factors, e.g. by stratification, composition and distribu- 
tion of the rocks near the surface. However, it is above all the 
more or less horizontal transverse faults, the gaping transverse 
fractures, the more or less vertical longitudinal faults, and the 
gaping longitudinal fractures, that chiefly govern the morphological 
aspect of the earth’s surface, leaving out of consideration the local 
areas with strong bending of the geanticlinal axes. According with 
the nature of the rocks, insignificant fractures of various trend may 
occur everywhere near the surface of the moving geanticlines; we 
consider only those areas of the geanticlinal surface where the 
faults, through more or less equal position and more or less equal 
direction of movement, bring about considerable alterations in the 
broad outlines of the morphological structure. Indeed, near the 
surface of the geanticline, zones of constant lithological characters 
may generally be separated by planes, which are parallel to the 
geanticlinal axis. If these planes are more or less vertical, this will 
chiefly influence the distribution of the vertical longitudinal fractures 
and the longitudinal faults. If these planes are principally more or 
less horizontal, this will chiefly influence the distribution of the 
horizontal faults, along borizontal planes, but the latter faults do 
not in the first place govern the morphological structure, and are 
left aside in our speculation. Accordingly on the distribution of the 
transverse faults, which really govern the morphological structure, 
the lithological character of the geanticlines near the surface exerts 
only little influence (at least as regards merely the major structure 
considered by us). And if the said planes near the surface are 
principally more or less horizontal, either in their original position 
