Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1882-06-17
An INTERESTING FIELD OF STUDY.


Henry Sleight, of Yuba county, writes
to the RECORD. UNION concerning an inter
es.ing field OF study. He says:
Many interesting pages in natural his
tory are revealed by the development of
mining enterprises and in washing aurifer-
GUS deposits for the precious metal. The
hydraulic brings to light fossil remains of
the fauna and fora that fiourished in the
post. pllocene times. New York Flat,
beautiful little valley near Brownville,
Yuba county, is yielding its alluvium to
the continuous pressure of the hydraulic
pipe for width of nearly 600 feet.
A superficial deposit of foot or two of
sand and gravel, from washings of tributary
ravines, overlies about three feet of black
loan; then from fifteen to twenty feet of
clay, of greenish- gray color, rests on an
evenly. strewn bed of gravel, varying in
thickness. however, from a few inches to
two or three feet. By examining the
formation YOU will find fossil rerains of
plants through the entire deposit, of the
same growth and varieties as those of to-
day found in the vicinity. As the valley
has a gentle fall of about an inch to the
rod, it has Of course always been
wet, and much of it formerly
swampy. Hence lherbage of the juncus
genus has predominated. Here the in
evitable willow found suitable soil, and
vast quantities may be seen well pre-
served; also cedar, madrone, pine, to-
gether with cones and foliage, etc. There
are no petrifactions in this section. Cedar
has undergone the least change, and occa-
sionally a section of tree is seen on or near
the bedrock that ia nearly as hard and tough
as when growing. The writer examined
cedar stump twenty-five feet below the
present surface of the valley, and found the
roots penetrated in the disintegrated granite
bedrock Just as it had grown. 1t had
been burned off quite close to the firm rock
in which it grew, ere it had been superin.
numbered with alluyium. Charcoal, and
the charred remains of trees, are seen in the
gravel and on the bedrock right where the
gold is found. In certain places regular
jam of drift-wood is unearthed, such as a
freshet might deposit now. Again, we
come to mass of rounded Jumps of clay,
indicating the action of water in making
gullies and causing the banks to cave after
the deposit had been formed. Fossil re-
mains of the mammoth the mastodon-
and other pachyderms are occasionally dis
covered in the gravel, or resting i'm
mediately thereon, which would seem to
prove conclusively that these extinct nam.
malta existed coeval with the formation of
the gold fields of the Pacific, or that the
period of time that marked their subse-
quent advent was geologically brief, and
that it was in the pliocene times when the
superficial earth was blessed with its great
WeaItn IN the precious nie1ai. Dus uurihg
TINS period there Is no evidence 10 De lound
of the presence OF man, Tor all the stone
mortars, arrowpoints, ETC., are discovered
from the surface to depth not exceeding
ten feet. My observation OF many years
in the mines in this vicinity Justiiies me IN
saying that none were found Embedded IN
the original gravel strewn on the bedrock,
where the remains OF the aforementioned
extinct quadrupeds have been unearthed,
and careful inquiry OF other miners con-
firms this. These facts are interesting to
the miner, and they are worthy OF the con-
sideratlon OF the geoioglst and paieontolo-
gist. The dIluvlal deposit OF this valley
Is composed OF greensboro, trachyte and
quartz Lodges, all OF which are to be seen on
the adjacent hills In tact they are OF
trappean origin. bikes OF greensboro from
few inches to two or three feet wide
traverse the valley obllquely, sometimes
showing half dozen faults in the distance OF
hundredfeet. Oneinterestlng phaseo OF this
little valley is the gas that bubblesup through
the bedrock in so many places, and con.
tinuously. Ihe alkah that forms on the
rocks in dry weather has nauseous, bitter
taste, The good water issues from the