Title: Interpretation of resistivity soundings from San Ignacio, Honduras

Abstract

The San Ignacio geothermal field is located in the central
part of Honduras. The rocks in the area are primarily of
Paleozoic metamorphic origin, overlaid by Tertiary Padre
Miguel Group tuffs and alluvial deposits. One-dimensional
interpretation of Schlumberger resistivity soundings revealed
that the alluvial deposits have a relatively low resistivity
and hence obscured possible interesting resistivity structure
in the underlaying basement. The geothermal surface
manifestations are located where a NE-trending zone of most
recent tectonic activity, west of the Arenal-fault ,
intersects a WNW-trending fault bordering the northern part
of the Siria valley. A low-resistivity anomaly is present in
the southwest extension of the zone, covering an area of 15
kro2• All this together with the presence of the sinter
deposits north of La Tembladera might suggest that the
geothermal activity is related to this NE-trending fault zone
and the low resistivity could be caused by geothermal fluids
conducted by these faults and infiltrated into the valley
fill.