Volume IV No. 1 - July, 1931
Carbonized Wood - An Index From The Past
By D. S. Libbey
Recently there have been found several large logs which are
completely buried under an overburden of volcanic tuff and agglomerate.
Some of the logs exceeded fifty feet in length and they were found
resting in a horizontal position without any evidence of roots or
stumps. Also there were no small branches attached to the logs but
several small branches found detached indicative that both the logs and
the smaller branches had probably floated to the place where they were
subsequently covered by the heavy burden of volcanic material. The
depth at which these logs were found in the volcanic tuff varied from 22
to approximately 60 feet with the conditions thoroughly indicating that
there had been no disturbance since the time of their entombment.
The site of this find is about 23 miles directly west from the Rim
of Crater Lake along the banks of the Rogue River where excavation by a
steam shovel is being made on the now Diamond Lake Road just above Union
Creek. The carbonized wood is unquestionably found in-site and the
volcanic material - ash and pumice - apparently at some time in the past
had completely dammed the Rogue River and caused a reservoir or a lake
to be formed. Subsequently the Rogue has worn its channel through the
deposit of fragmental material and is now resting upon a vesicular lava
rock.
This material has an exceedingly interesting story to tell. The
material was buried under a thick overburden of consolidated volcanic
ash and pumice and is completely turned to charcoal. The logs
necessarily were entombed under very thick loads of hot ashes and the
heat, coupled with the rapidity in which the volcanic ejecta fell,
resulted in the oxygen of the air being excluded which is essential to
prevent combustion of entombed wood. As a result the wood material was
changed to carbonized wood or natural charcoal. Such material is
capable of preservation indefinitely and its presence can be discovered
even thousands or even millions of years later.
The presence of charcoal buried in the midden heaps where
prehistoric man abided is one of the most certain means to prove the
existence of early human habitation. This is mentioned in order to
illustrate the degree to which charcoal is indestructible under normal
conditions and that it is such a splendid time marker by which the
record of the past may be read.
The carbonized wood being buried under volcanic ejecta, ashes and
pumice necessarily forces the conclusion that a very terrific volcanic
explosion occurred to bury and carbonize the logs. The fact that the
logs were changed to natural charcoal forces the conclusion that the ash
and pumice was still exceedingly hot when it came to rest. The volcanic
tuff was found in several places to be interbedded with water laid sand
and gravels of a heterogeneous nature, suggesting a lake deposit in
which glacial material was deposited and also the very definitely
cross-bedded strata suggest off-shore conditions.
A complete assortment of the material is being preserved and a
record being made of the essential facts concerning the find, so that we
may correlate this find with subsequent discoveries of fossil wood,
carbonized vegetation or any other material which may be subsequently
found. This will enable the scientific investigators to piece together
a coherent story concerning the origin of Crater Lake and possibly lend
more data to prove or disprove the several theories which are prevalent
concerning the destruction of old Mount Mazama. Did the cone of Mount
Mazama collapse and then subsequent eruption build up the three volcanic
cones now found within the caldera? Did a terrific explosion blow of
the top of Mount Mazama, leaving the gigantic caldera which Crater Lake
occupies and subsequent eruption build up the volcanic cone of Wizard
Island and the two smaller cones which are of insufficient height to
protrude above the water level of the lake?
Did the volcanic ejecta, ash and pumice, which buried the logs and
changed these to charcoal, come from the eruption of Mount Mazama prior
to its final collapse or explosion? Did the ejecta come forth at the
time of Mount Mazama's final destruction? Is the ejecta in question the
explosive material of some adnate volcanic cone rather than material
erupted from Mount Mazama? All of these questions are easier to ask
than to answer. In our small way it is our hope to accumulate the
evidences of the past as we are able to discover them and thus be able
to piece together the correct story by eliminating the less probable
hypothesis.
Beavers In The Park
By D. S. Libbey
This season we are delighted to learn that within the area of Crater
Lake National Park we have living colonies of the American Beaver
(Castor Canadensis Pacificus), the national emblem of our sister
nation to the north. It is the largest rodent on the continent and a
member of the squirrel family which as adapted itself to life in the
water.
Mr. Fred Patton, one of the oldest employees of Crater Lake National
Park, called our attention to numerous beaver dams and fresh beaver
cutting along the west margin of the park in the vicinity of Copeland
Creek. Mr. Patton discovered the beaver activity while engaged in his
work of opening a motor way.
Specimens of the fresh beaver cuttings have been placed on exhibit
in the Community House and it is the plan to have guided motor caravans
conducted to the scene of the activity by the ranger force. Also very
careful efforts will be made to have the area adequately patrolled to
preserve the colony of beavers and to prevent their extermination by
poachers in the subsequent trapping season.
The pelt of the beaver is connected with the earliest exploration of
North America, and fur trading in the days of the Old West was carried
on extensively. Vast areas were discovered and developed because of the
powerful incentive to seek out the beaver and obtain his pelt.
It is our goal to preserve our beaver friends. Their works have
never ceased to be of perennial interest to man. So extensive the dam,
so large the trees felled by no other tools than their chisel-like
incisors, and so great the tracts of land flooded by the dams that the
beavers have become known as the emblem of industry.
A beaver dam is never complete. The busy colony is constantly
repairing it, adding fresh cuttings and shifting driftwood, stones and
earth so that they are inextricably piled together. The obstructions
create the pools of still water so desired by the beaver, and the
cuttings from last winter show clearly the snow levels at which the
animals were able to work.
The series of dams has materially changed the erosional activity of
the creek and has resulted in basins which are splendid reservoirs for
catching and preserving vegetable life which slowly decomposes and
yields the necessary humus material. This results in offering favorable
food supply for a more vigorous growth of flowers and trees which find
their ideal habitat in a swamp.
The series of beaver colonies was found about the 5,250 foot
elevation in the park.
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