Geology Reference
In-Depth Information
field
mapping. Tlemcen
University and
Hospital site,
Algeria.
Information gained from desk study and site reconnaissance can be
analysed and draped over 3D digital models using GIS, as illustrated in
Figure 4.14,
which greatly assists visualisation, interpretation and
planning of GI, including access.
4.4.2 Describing
field exposures
The task of describing a large
field exposure, say in a cut slope, can be
daunting, and the following procedure is recommended. The exposure
(natural or man-made) should be split initially into zones, layers or
units, by eye. The primary division will often be geological, i.e. rock
and soil units of different age, but then differentiated by rock or soil
mass quality such as degree of weathering or closeness of fracturing.
Differentiation on strength can be made quickly by simple index tests
such as hitting or pushing in a hammer. The split might be on structural
regime, i.e. style and orientation of discontinuities. The process is
