Page 87 - Introduction to Mineral Exploration

70 C.J. MOON & M.K.G. WHATELEY
5

From Prospect to

Prefeasibility

Charles J. Moon and Michael K.G. Whateley

Once land has been acquired the geologist must sion. The scale and speed of exploration will
direct his or her efforts to proving whether or depend on the land acquisition agreements (see
not a mineral prospect is worthy of commercial section 4.2.3) and the overall budget. If a pur-
evaluation. Proving a discovery to be of suffici- chase decision is required in 3 years, then the
ent size and quality inevitably involves a sub- budget and organization must be geared to this.
surface investigation and the geologist usually Usually the exploration of a particular piece
faces the task of generating a target for drilling. of land is given project status and allocated a
In exceptional cases, such as very shallow min- separate budget under the responsibility of a
eralisation, a resource may be proved by dig- geologist, normally called the project geologist.
ging pits or trenches or, in mountainous, areas This geologist is then allocated a support team
by driving adits into the mountainside. and he or she proceeds to plan the various sur-
Whatever the method used the key require- veys, usually in collaboration with in-house
ment is to explore the area at the lowest cost experts, and reports his or her recommenda-
without missing significant targets. Fulfilling tions to the exploration management. Typic-
this requirement is not easy and the mineral ally, reporting of progress is carried out in
deposit models, such as those discussed in monthly reports by all staff and in 6-monthly
Chapter 3, must be modified to include eco- reviews of progress with senior exploration
nomic considerations. There should be a clear management. These reviews are often also oral
idea of the size of the deposit sought, the max- presentations (“show and tell”) sessions and
imum depth of interest, and whether under- linked to budget proposals for the next fin-
ground mining is acceptable. Finding a drilling ancial period.
target normally involves the commissioning Reconnaissance projects are normally dir-
of a number of different surveys, such as a ected from an existing exploration office, but
geophysical survey, to locate the target and once a project has been established serious con-
indicate its probable subsurface extension. The sideration should be given (in inhabited areas)
role of the geologist and the exploration man- to setting up an office nearer the project loca-
agement is to decide which are necessary and tion. Initially this may be an abandoned farm-
to integrate the surveys to maximum effect. house or caravan but for large projects it will be
a formal office in the nearest town with good
communications and supplies. A small office
5.1 FINDING A DRILLING TARGET of this type is becoming much easier to organ-
ize following the improvement of communica-
tion and computing facilities during the last
5.1.1 Organization and budgeting
decade. Exploration data can be transferred by
Once land has been acquired, an organization modem, fax, and satellite communications to
and budget must be set up to explore it and even the remotest location. If the project grows
bring the exploration to a successful conclu- into one with a major drilling commitment