The Richmond Virginian. (Richmond, Va.) 1910-1920, 1913-09-01
PANAMA ASH HEAP
$1,000 FEET HIGH
GEOIOGTsT MCDONALD TELLS OF
RESULTS OF RECENT SGIEN-
TyEIC EXPEDITION

Tr. T. r. Mcdonald, the geologist Of
the Panama Canal Commission. has Just
completed a tour Of western Panama,
and IN the last issue of The Canal
Record. the official bulletin OF the
commission. which reached New York
Yesterday nr. Mcdonald tells some of
the results Of his trip. The trip lasted
two months and was made under the
ausplces of the Smithsonian institution,
the Panama Canal Commission, anu
the United states Geological survey.
"The full results" pr. Mcdonald SAYS
in The Canal Record, "of the journey
v hich lasted about two months, Will De
published later by the Smithsonian IN,
st{tut{on In this issue the so~called
Chiriquf volcano will be briefly treated,
perhaps the most interesting new
thing discovered about tho extinct vol
cano was the evidence that indicated
about the number Of centuries thht
have elapsed since the last volcanic
outburst. II will be remembered that
about Il year ago the newspapers TOT"
how an eruption Of Chlriqui volcano
had flung death and destruction far
over Western Panama This proved 10
/ no a newxnaper story for the last
explosive outburst OF the mountain did
! not occur In 1912, but many hundred
centuries earlier.
| "'rhe majestic Chtriqui peak stands
as a king among mountains. Tower
1 ing over II 600 feet above sea level IL
ovcrlooks all the other rugged crests
Of Western Panama. From Its summit,
on "A clear day. one can see the VIDE
coastal uiain OF David meeting the low
/ living shore of the Pacific, forty miles
away Streams like oose-lylnR
stlvery threads flung ocean ward, We
the mountains to the sea, ana on tae't
! banks here and there are distant specks
Of ALTERNATIVE villages Scattere"
grazing herds dot the nearer plains
and q tiny dust cloud. barely visible In
the blue haze Of the distant valley, tells
of a train Of bull carts toiling from
David out to the coffee plantations
near the foot of the mountain.
Turning then to tie northward., one
may behold lesseniut' waves of noun
tains dimming In the distance. where
they meet the wide embayments or the
Caribbean short. In the babys and be-
vOnd the headlands dark island spots
are scattered along tho landward mar
gin Of the sunlit sea, These remnants
/ Of a submerged mountain group stand
like a struggling rearguard protecting
the main shore line against the foam
crested trade wind waves.
Gazing out over this pleasing pic
shocked when he realizes that he If
only on the top Of an ash heap. Tor
this mighty peak was built up hY
carnations Of volcanic ash ana DEBRIS
blown out during long centuries from
crater, or group or craters- lh'
last explosion. or series of EXPLOSIONS
was more violent than the rest. for u
blew the top off the mountain, ana scat
tered the debris far and wide, huryine
Z under some
hundreds OF feet of volcanic ash anf
ptectanenta Later. streams formed or
the new surface and these slowly en-
trenched themselves in the new vol
canlc formation The Caldera river
thus excavated for itself canon tina
is $50 feet deep and about half mile
wide-~a vaster trench by far than
!; Culebra Cut. and all done by a river
without driI, powder or, steam shovel
In the fiat, wide bottom of this canon
close to the bank of the stream arr
. some old indian graves, and near by
are some carved stones, or 'piedra'
pintadas
From the weathering OF these, anC
from tha pottery and other objects
remnants of an ancient indian culture
y buried In them, 1t is known that the!
: are at least l.o40 years old, and prob
ably considerably more. Since thes'
graves were made, the Caldera five
- has not. cut its channel more than II
feet deeper over about. one-tenth q
the total width Of it's valley bottom
. This ts equivalent to "A deepening o
the whole width of the valley on
foot.
The Rate of Excavation.
From these data Il is seen that tn
2 minimum rate OF excavation of tn
q Caldera valley. under, approximately
present conditions, would be one foo
per thousand years. AT this rate III
- present valley. which Is $50 feet deer
v would require $50, 600 years for excaya
ton However during the first fev
centuries excavation of il went ol
n much more rapidly than now. This /
e due To the fact that in falling througl
g the atmosphere the coarscr rocks o
volcanic debris dropped faster. and ar
more concentrated in the lower par'
8 while the upper parts Of this forma
n tion are chiefly Of fine ash, Hence tn
= work OF washing out Caldera Valley I
r it's present form was not fraught wit
rnush difficulty while the river WA
tcutting through this fine top materta
q Later the river channel became some
= what choked by the boulders that &C
cumulated In II as the canon was Gu
deeper and the work of erosion wa
: thus much retarded.
= III is also known that volcanic ex
a ploslons are generally followed b
great downpuurs of rain. Such flood
must be- considered in the time est
h. mated for they would generally haste
the early work Of erosion, In order I
~ allow for the more rapid digging out {
Il this canon by the stream, in the earl
. stages Of its history. there might be do
| Quoted 80 IL per cent from the ahoy
| mentioned estimate of time. In est
| mating conservatitely. the minimul
| time since the last eruption, SO DC
| cent may be deducted from the fir
estimate Of 35N.0 900 years. leaving a pr
l Rod Of l7E0o0 years as the least tim
$3.50 since this kingly mountain fell ava
- from the pytotechnic grandeur OF II
. former estimate, and became dead
good-volcano."