The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1899-03-24
ABOUT PORTO R|CO'S MINERALS
ABUNDANT AS; THE SNAKES OF
IRELAND.
Government Geologist Found Very
Little Gold and Some Copper
Stains-Peculiar Conditions.
(special Correspondence. }

\Specldl OolTeSpOnuSnCe.)
Washington, March 20.-The report
by Robert T. Hill of the geological sur
yey ON the mineral resources of our
new possession, Porto Rico, is sure to
prove disappointing to the many Amer
leans who have tancied that there
might be untold treasures under her
mountains. He says the metallic min
erals most frequently found, and which
form the object of much search, are
gold, carbonate and sulphide of cop
per, and magnetic oxide of iron. Traces
of lead and indications OF mercury
manganese, and biSmuth have also
been noted. Almost since the date of
the discovery of the island gold has
been washed in small quantities from
many of its rivers, especially those OF
the north and east end, notably the
Luquillo and Lola. Gold also occurs
in the streams near Corozal, a village
on the north central side of the island.
1t has never been found in great guam
titles, so cents to 81 a, day representing
the average product of a hard day S
labor. The gold is obtained by the
natives from the river sand and gravel
The mother rock of this metal has
never been determined. Lately a great
many American prospectors have been
seeking for quartz veins toward the
ion, however, that such will not be
found, as there are no evidences of
their existence upon the island, at least
no visible quartz veins could be de-
tected by me anywhere although there
may be small s'tringer veins. 1t is
more probable that the vein material
of the gold in the mother rocks is py-
rite, as this is quite, frequently en-
countered along the contacts.
PrOfpccOr Hill ceauc uIiIa ic
possible to reach any positive conclu-
sion as to the quantity or value of the
gold of the island, experience has
shown that the placer deposits are not
rich or extensive The question of it's
occurrence in the mother rocks is a
problem which will require careful and
patient exploration by scientific meth
DDS. The prospector from the United
States will find that the matrix is en-
tirely different from that with which
he has been familiar, the general ge-
ologic conditions resembling those of
Colombia and Panama, more than those
of the North American gold fields.
Copper pyrite and the stains of car
Donate of copper are frequently met
with in the central mountain region of
Porto Rico, but nowhere in quantity
sufficient to justify expectations of ex-
tenSiVe occurrence.
cusses the striking difference, in oc-
currence and appearance, of the econ
orrlic resources of Porto Rico from
those of the United States, and of the
North American continent in general.
The geologic type, of the island is An
tillean in its aSpectS and the sequence
arrangement, and composition of the
rocks are entirely different from those
of the rocks with which we are IA
miliar in our country. The matrix and
country rock of the metallic minerals
are not of the quartZiferous type IA
miliar to prospectors in the United
States, but are made up entirely of
basic igneous rocks, such as tufts and
volcanic conglomerates, of the kind
known in Central America and Colom-
bia as "caleche," while the dixie and
vein material is largely of hornblendic
andesite- porphyry. Furthermore, the
bituminouS material, instead of occur
ring in rocks Of the Carboniferous pc
Rod, as it largely does in the United
States, is found entirely in strata of
the Tertiary period. The ordinary
prospector will find these conditions so
foreign to those of the United States
that he will be entirely lost in endeavs
oring to follow what are to him ordi-
nary indications of mineral wealth.
Owing to this fact, he says, it is nee
'essary that the mineral resources of
Porto Rico should receive thorough
scientific study and exploitation In
his opinion such investigation may re-
suit in the discovery and development
of many interesting resources which
have escaped the observation of prac-
teal mining prospectors and my own
eye in my brief reconnaissance. 1t is
especially Important that the sands
and alluvial deposits of each of the
1,200 streams of the island should be
carefully studied, FOR it is possible if
net probable, that they contain platin-
UNI and ether rarer minerals. He is
inclined to the latter opinion because of
the resemblance of the formations, in
a general way, to those of Colombia.
in which these minerals occur. Fur
thermore, the contact phenomena are
worthy of scientific investigation, and
the phosphate limestones of the coast
al formations deserve systematic study.