572 
or after overthrust-movements, the lithological character affects the 
development of the vertical longitudinal faults only very little, so 
that then again the morphological structure is governed principally 
by direction and velocity in different places of the moving geanticline. 
If the crust near the surface does not undergo the direct influence 
of the compressional stress, in the main only passive displacements 
will appear here. In forming a judgment of the genesis of fractures 
and faults this should be borne in mind. 
When in the following pages faults are spoken of, we presume 
it to be possible that monoclines occur, which are essentially allied 
to faults. 
Movement of the geanticlines. 
The movement of a geanticline can be broadly described by indi- 
cating in the first place how the projections of the geanticlinal axis 
on the horizontal plane and on a vertical plane approximately paral- 
lel to the part of the geanticlinal axis under consideration, are moving. 
When we then consider the section of the surface of the geanticline 
with a vertical plane at right angles to the geanticlinal axis, it is 
also a matter of importance how this section will move. In this 
communication we only consider the movement of the horizontal 
projection of the geanticlnal axis. 
The movement of a geanticline, which can move more or less 
freely in a horizontal direction, e.g. as a row of islands in the 
direction of the ocean, will show itself for the greater part in the 
movement of the horizontal projection. Extension by bending at 
greater depth, will perhaps be visible near the surface in more or 
less regularly distributed, more or less gaping transverse or diag- 
onal fractures and faults. Straits may occur at the place of such 
fractures. In the row of islands Sumatra-Java-Lombok-Flores, e. g. 
numerous transverse faults occur near Strait Sunda and nearly 
always the western portion is moved towards the South’). Along 
the fault-plane of the Tji-Tjatih near Sukabumi the displacement 
amounts to 4 k.m. at the very least, along the fractures of Sunda 
1) R. D. M. VerBeeK and R. Fennema. “Geologische Beschrijving van Java en 
Madoera” 1896 p. 539. L. J. C. van Es. “Geologische Overz. kaart v. d. Ned. 
Oost-Ind. Archipel. Toelichting bij Bld. XV. Jaarb. Mijnw. Verh. 1916 II p. 132 
sqq. The faults now visible have, at least in part, originated already in earlier 
times, during an earlier phase in the orogenetie process, under a load of sediments, 
and along many of them the movement may have stopped by this time. The 
morphological structure is now governed especially by the faults in the neigh- 
bourhood of Strait Sunda. 
