Lesson 1/Learning Event 4
Learning Event 4
The pit or quarry sites located from your survey should be field checked. You must first establish
priorities for such further investigations which will provide the data necessary for final site selection.
You will determine the scope and nature of any required subsurface exploration. Investigation priorities
are classified as known sites, probable sites, and possible sites.
Known sites are those sites currently or previously used as pits or quarries. They are close enough to the
construction site to warrant further investigation.
Probable sites are those that your survey found to contain desirable construction materials.
Possible sites are those sites for which your survey indicated a possibility that construction materials
exist. Information on these sites may have been obtained from visual or aerial photographic coverage
and must be confirmed by individual investigation.
Subsurface investigation should be minimized by a thorough survey. Where necessary, a number of
exploration methods are available for use. Geologic mapping, probings, wash borings, auger drilling,
drive sampling, pneumatic drilling, and test pits and trenches are the more common methods. Of these,
test pits and trenches are the most reliable and widely used. Core drilling and geophysical
measurements are two other methods which are not normally available to field troops.
FINAL SITE SELECTION
Final selection of a pit or quarry site is made after all reconnaissance and exploration data has been
collected, analyzed, and evaluated. To determine the most suitable site, the quality and quantity
requirements must first be met. If more than one site satisfies these requirements, your ultimate choice
must be based on location, equipment and personnel required, ease of operation, and other factors. The
weight you assign any given factor in your evaluation will depend on your particular situation. For
example, security may be a major consideration in a forward area, but a relatively minor one in the