Since 1969, a substantial number
of geophysical methods have been
applied in the search for porphyry
copper and mesothermal type -sulpha-de
deposits. These have assisted with
geological mapping as well as the
definition of various sulphide depos-
its. The application of these methods
at the Frieda-Nena deposits, Papua New
Guinea, can be used as a case study for
exploration in other parts of New
Guinea.
In 1993, Highlands Gold Limited
carried out an intensive geophysical
program over the Nena deposit. The
methods employed included, CSAMT
(controlled-source audio magneto-
tellurics), airborne and ground elect-
romagnetics, IP/resistivity and ground
magnetics. The magnetic method was used
as a regional mapping tool as well as
a way of mapping alteration zones over
both the Nena and Frieda River copper
deposits. Electromagnetics, in part-
icular FLAIRTEM, is a rapid reconn-
aissance tool as well as a detailed
mapping tool for the location of Nena-
style massive sulphide deposits. IP/
resistivity is an expensive but most
useful tool for mapping out Frieda
porphyry copper style disseminated
sulphides as well as Nena style
deposits. It can be used to define
drill targets in areas of difficult
Access.a