Rock appearance

from Wikipedia, the free encyclopedia

The term Felsmutung are geophysical methods summarized that the location and depth determination of bedrock are underground. The term is no longer used often because the methodology is now integrated into more comprehensive procedures.

The conjecture of rock is particularly important for geotechnical engineering - and the more reliable the more the searched material differs physically from the overlying sediment layers: for example in its density , its elasticity ( modulus of elasticity ), electrically or magnetically . Rocks at shallower depths are generally easier to locate than deeper ones; a different inclination compared to the hanging wall also increases the quality of the interpretation.

The first purpose of a rock appearance is usually only to determine the position (possible depth) of an underground solid rock , in contrast to the exact course of this rock unit and its stratigraphy . The exploration method is part of applied geophysics and is often used in initial investigations, for example for the depth of glaciers , for scree slopes or soil stability ( landslides ) in mountains or for the foundation of structures.

The word derives from the mining notion of presumption from which mining authorities authorization to operate a mine in the requirement to demonstrate that the planned mine is able to find - so a successful presumption on the ground - was a prerequisite. Today this term stands for prospection as qualitative location.

The most important geotechnical applications of rock formation are the determination of the depth of near-surface sediments and debris heaps, etc .; In geological terms, it is mainly used in glaciology (ice thickness measurement) and partly in hydrology .

The methods used are:

  1. the seismic , at shallow depths, in particular, the hammer seismic;
  2. the gravimetric and the ground-gradiometry;
  3. the ground radar ;
  4. local applications of geoelectrics .

Sources and literature

  • FK Bauer, R. Oberhauser (edit.): The geological structure of Austria. Federal Geological Institute (Ed.), Springer, Vienna / New York 1980, ISBN 978-3-211-81556-4 .
  • H. Kohnen, C. Bentley: Seismo-glaciological investigations near Byrd Station, Antarctica . In: Meteorology / Atmosph.Physics 22/2 + 3, Springer-Verlag, 1973.
  • W. Embacher: Rock appearance on the portals of the planned Tauern tunnel. Internal report for Tauernautobahn AG, Salzburg 1968.
  • Erwin Gigas: Physical-geodetic measuring methods . Dümmler-Verlag, 1966.