Structure of Rock - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 18

The clay slate represented in Fig. 2.18 is an example of a rock mass with an orthogo-
nal system of vertical discontinuities (D1 and D2) and horizontal schistosity-parallel
discontinuities (Sch), which in this particular case have the same orientation as the
bedding.
Fig. 2.19 illustrates a tuff, as an example for a pyroclastic sediment. Such a rock mass
often exhibits practically no discontinuities. The same is true for the rock salt repre-
sented in Fig. 2.20 as an example for a chemical sediment.
The water solubility of chemical sediments can lead to large openings in the ground.
Figure 2.21 shows a schematic section through the White Jurassic formation at the
Swabian Alb. In the banked limestone, which has been subjected to the Rhenani-
an karst formation, various karst structures appear, such as karstified master joints
(Fig. 2.22) and large karst channels (Fig. 2.23). In the overlying massive limestones of
the Danubian karst formation major karst structures such as horizontal and vertical
caves, holes and larger cavities can be found (Fig. 2.21).
Figure 2.16 Claystone, Black Jurassic (Lias α ), Stuttgart (Germany)