The Nome daily nugget. (Nome, Alaska) 1906-1918, 1908-11-18
new THEORY OF GOLD
ON THE BEDROCK

Tho concentration IT gold 10 rivet
gravcls always tend- toward amtrt-
ment Al bedroct. or j, intermediate
clay parting. in tby Dirt Tins sim
rDe fact If observation Is ~, easily
cxrlainahlc. as might appear at first
sight Tn analogy If concentration
in sluice is Of only II limited arfHea
ton The concentration II casIs.. gold
ia the strrplv- inclined upper reaches
of stream here The entire mass
of gravel is subject to frequent dis
umbanco and rcauangemeut h, floods.
depends. uf course. upau fHr same
principle It, that which the hydraulic
miner has aIuayz employed Thu con
centratiou Of gold in what are known
rs high banks is also comprehensive
biz. This represents the deposition in
cddies during pefiods af high water.
Tae Ihcnamenon is peculiar a. an
gold bearing districts that arr subject
L. sudden floods tn distribution II
gold in fans. where rivers drhouch
from narrow valleys upon plain. is
referablc Ia the seour of a river chan
mel in which concentration Of gold had
previously taken place. and the zones
Of superior enrichment through such
Tan deposits" apparently represent
successive deep seourings of the upper
valley by extraordinary floods The
accumulation of gold almost invariably
in larger amount on the bottom of the
channel is not 50 easily accounted for
The actual turning over of tho dep
gravel-fll as sand and gravel are
moved forward in a sluice. demonstra-
bly, has not taken place. W. have
seen drilI holes penetrate The vaIley-fl
To depths Of thirty-fy to forty five
feet through coarse sand. containing
no pebbles larger than two inches i'm
diameter without revealing single
gold color until bedrock Was reached
Also. in a md Californian valley de-
posit we have seen an exactly similar
phenomenon occur both on "false bot
tom" and on the true bedrock twenty
feet below IT, ManifestlS the principle
has not applied in such case. In a
recent bulletin Of the New Zealand
geological survey Mr. James Park dis
cusses the concentration Of gold in
river gravels IN a very able manner.
but he does not grapple with the pc
culiar problem We nave stated here.
although an extension Of his explana-
ton If the progressive settlement of
gold through gravel subject to move
ment in a current Of water is all that
is needed to adequately account for
the phenomenon. We must conceive
a change in conditions however. which
involves a consideration Of movement
infinitely slow as compared with the
flow of wet sand on a steeply inclined
channel We know that the soil-cov-
ering. which may be more accurately
because more broadly denominated the
"regolith.' as suggested by MIR G. +.
Merrill is not transported to lower
levels by means of wash from the run
off Of the rainfall, but when saturated
with water does actually flow not un-
like a viscuous body This phenome-
non has also been pointed out by nu-
merouS students Of soils both i'm
America and abroad The same move
ment is indicated as a characteristic
Of sand and gravel fills OF river chan
nels and even Of broad valleys II
may be compared to the slow. steady
persistent downward movement of a
glacier This movement has largely
escaped detection. most likely because
it was unsupported Even Mr. Park
after his critical study of gravel de-
posits has failed to note this. This is
probably because the opportunities &C
study very fat sandy valley fills by
means of a sufficient number Of bore
holes to afford data for safe general
izatiOn have not been frequent. The
case is not yet absolutely demonstrat-
ed to the point of determination o.
velocities of movement Of water sat
urated sandy valley deposits. and OBJ