REVISTA DE OBRAS PUBLICAS DE PUERTO RICO
577
Information Circular United States Bureau of Mines Essentials for a preliminary report on a small lodge-g oíd mine or prospect, wish notes on sampling.
By
Charles Will Wright
(Clvef engineer, mining división, U. S. Bureau of Mines.)
This paper has been written to aid the owner of a small gola mine or prospect in preparing a report on his property for the purpose of interesting capital.
f
an owner can afford to do so, he should employ a mining engineer of reeognize standing and experience to examine and report on his property but many owners of small mines and particulariy of prospects cannot m^ke the expenditure required for this. Further,
many
them do not know how
of
to prepare a des-
cription which will cover those features of a deposit on which a potential investor promises his opinión as
convmced that he possesses an orebody of sufficient grade and size to warrant the required expenaiture íor a thorough investigation and wishes to present his property to prospecto its worth.
if
such an owner
ís
theñ the following suggestions concerning the proper way to sampie his deposit, estímate the tonnage oí üeveicped ana probable ore, and prepare a tive investors,
report
may
be of assistance.
The prospector us ually has
insufficient funds,
m
it ís
m
necessary beí'ore the property can became productive. Tne owners may put up capital for a small mitial piant to gec the property meo production, but often senous mistakes are maae in selection of mine equipement and the method used in mining or ore treatment which may iater be responsibie for tne íailure of the operation.
Otten, too, venere smaii milis are instaliedand insufíicient capital is available, ore is it is
developed in order that
consumed as fast as
its yield
may
be applied
toward payment of expenses. Unless an immeaiate profit is made the mine fails, whereas if the available capital had been.spent on development, the property might have been in excellent condition for examination and sale.
An
always more interested in the grade and tonnage of developed ore than in any mili which investor
installed.
If the
owner has not the
ca-
spend the
available funds on development, leaving the expend-
an ore-treatment plant to the future investor. Besides prospects and small mines in precess of
iture for
development, there are a large number of partially c'eveloped gold mines in the United States where active operatinos have been discontinued. Some of these properties under the favorable conditions existing today regarding equipment, labor, and supplies, and because of recent improvements in mining methods and ore-dressing practice, might become profitable producers.
If
the owners of such mines wouli prepare a
report along the lines suggested in this paper aid
them
in
it
would
obtaining capital to rehabilítate their prop-
erties.
SUGGESTIONS REGARDING THE PREPARATION OF A PRELIMINARY REPORT
and
necessary to prove the extent of his deposit some oegree betore an engmeer examines it, he often geis iocaí ousiness men to suppiy funds for developreturn for an interest in the property. ment work if explorations open up a persistent body of ore with prospects of tonnage, development of the orebody is as
may have been
pital required for a mili it is advisable to
The following
outline of a preliminary report on a
small lode gold mine or prospect reral guide which
may
is presente i as a gebe modified to suit any indi-
vidual property.
Summary Start the report with a short summary giving the of the property, its location and ownership, size
rame
and type of the deposit, characteristics of Ihe ore and adjacent country rock, the average grade of ore, production if any, the amount of development work, the tonnage blocked out, and briefly describing labor, water, and timber supplies and transportation f acilities. Terms for an option and a short statement setting forth the investment possibilities of the property t
rhould also be included. This summary wlI give the reader a general idea of the major features of the report which follows and will assist him in grasping its details.
Location and Accessibility
is
(1)
Ñame
the state, county, and mining district