of the strike and dip of fracture in cores (Fig.4-1) is
an important task to estimate the geological structure of
the geothermal field, as well as to estimate the path of
geothermal fluids (Fig.4-2).
The measurement of the dip in a core fracture is simple,
but not the measurement of its strike because the orientation
of the core is hardly defined. This is the reason why measurements
of both, dip and strike, is not included in the core fracture
Recently, sampling techniques of fixed core orientation
have been developed, but because of their high cost, these
sampling techniques are not of general use.
fill this gap, West JEC in collaboration with NEDO, developed
a system to analyze both, dip and strike of fractures in
cores using thermo-remnant magnetization (Fig.4-3).
This system has been useful to estimate, during geothermal
development surveys, the strike and dip of the faults playing
the role of reservoirs (Fig.4-4). Especially, in the case
of all coring well, this technique is useful to assess the
location and extent of the reservoir.