New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1886-09-24
DIAMONDS IN KENTUCKY

AT the late meeting Oh inc Driuish hsSVNia'
! ton a paper of special interest to Americans
was read by Professor H. Carvcll Lewis, before
| the geological section. 1t was entitled ga
| diamond bearing pcridolite, and the genesis oil
| the diamond" The professor drew his argu-
| ments from an investigation OF the klmocrley
diamond field in South Africa. When diamonds
were first found there, in 1867. the so-called
| "dry diggings" were believed to be aluvla
deposits, but it has now been ascertained that
they are really volcanic pipes or tubes, OF
highly interesting character. In 1870 and
1871 further fields were discovered at Kimbcr-
lev. and all had the same geological structure,
each being a separate pipe, and all rich in dia-
monds. 1t was soon discovered that the pipes
went down vertically to an unknown depth,
penetrating the surrounding strata. The dia-
mond-bearing matter, when first penetrated,
was soft, yellowish friable substance, readily
crumbling when exposed. AT a depth OF
about one hundred feet it became darker and
harder, and finally acquired slatc-blue color,
varying in places to dark green.
Recent excavations have showed that the
mines arc surrounded by much carbOnaceous
black shaIe These shales "were very COM
bustible and carbonaceous, and extended at least
forty miles away from Kimberley, underlying
the whole district The question put by Pro-
lessor Lewis was whether the presence of these
carbonaceous shalcs did not explain the genesis
of the diamond, a problem hitherto unsolved.
He called attention TO the fact that the diamonds
were most abundant where the pipe was sur
rounded by shale Earlier speculations con-
corning the origin Of the diamond had, he said,
given way to the theory that the diamonds be-
longed to and formed part of the matrix in
which they were found and that that matrix
was in some way of volcanic origin, either in
the form of mud, or ashes or lava. The new
hypothesis assumes that the diamonds were
formed in the volcanic pipes where they are
found. by the action of chemical processes set
in motion by volcanic force. All exploration
tends to confirm the belief that the deeper parts
of the pipes and where presumably the chemical
action was greatest during the formative period,
contain the richest deposits, and 1t is further
supposed that the pipes descend to very grca;
depths, and that originally they communicated
directly with the fused and plastic mass under
lying the crust Of the earth.
All this is interesting, for, the president o.
the section, Professor Bonney, observed at the
conclusion of the reading, ait seems rs if Pro-
lessor CarvcL Lewis has at last arrived at the
true theory OF the genesis of the diamond
But the most interesting statement made by
Professor Lewis remains to bc mentioned. II
is to the effect that the only place in the world
known to biologists where the same peculiar
geologic phenomena occur as are found AT Kim
bcrlcy is 10 Kentucky. There the conditions
so closely resemble those of the South African
diamond fields to Justify the professors con-
Gdcnt prediction that diamonds, II sought for,
viii also Lc found in the American Stale. The
importance Of this prediction Is perhaps con
siderable II Is certain that there are carbonif
crous beds iii Kentucky, though the existence
Of the volcanic pipes filled with the pcridollte
which Professor Carvcll Lewis holds TO be the
Inatrix Of the diamond has not been generally
known, or if known 10 biologists has been re-
garded as possessing no particular significance.
No doubt the professors bold prediction will
at once stimulate research in the region indi-
Gated, and American biologists may expect
before long to be flooded with demands for sucn
information will enable speculative capitalists
and ad vcnturers to put the new theory to the
test The actual discovery OF diamonds In
Kentucky would he an event Of great im
portance, and the serious suggestion Of such
a source Of wealth by prominent man of science
must attract general attention and insure
prompt exploration.