The silver state. [volume] (Unionville, Nev.) 1870-1903, 1879-04-25

What a scientist says About Them.

considerable poiltencSS Oh Judge Allllam
s. Bonnifeld of Winnemucca, Hum
boldt county Nevada, have been pre-
sented with fine collection of curious
fossil molusks (genus n,stelus eduiis),
which have recently been discovered in
enormous beds in the second bank, or
alluvial terrace, of the Humboldt river,
at the town of Winnemucca. Although
these fossils are considerably metamor-
phosed by the elements, still the pearly
Nominations of the inner surfaces of the
shells are pretty well preserved, and
when properly cleansed from incrusta-
tions are extremely bright and beauti-
full. That these shells belong to the
tamellibru1chs is quite apparent, but
their decayed condition renders it diff
ficult to determine the precise species.
They are probably, however, congeners
of existing species which are found IN
great numbers in the Ohio and other
Western rivers. As no species of hmet-
Ebranch now survives in the Great
American Basin, these fossil beds are
interesting objects to geological stu
dents. In the Humboldt and Carson
rivers there is living species of mo,
bat it has no resemblance to the nytili9
of the yVinnemucca beds. In fact the
existing species have an exact congener
i'll the myocene sandstones at the Ne
vada State Prison, in Carson valley; but
those in size, form and internal struct-
ure are obviously different from the
Winnemucca fossils. Many of the
specimens sent to me will measure four
inches in length, while none of the hv-
ing bivalves, nor Of the tertiary Unios,
will exceed two inches in longitude.
The truth is evident that the Winnie
mucca fossils belong to remote period
in the Typographical structure of the
Great Basin.
az Viz N4OoS Va OaittO iS1hai httoiO XIV
logical period denominated the Second
Quarternary, were left innumera1e
visible evidences in the topography of
Europe and America to prove that the
northern hemisphere of our planet was
subjected to the process of gradual
elevation, and that by this means, the
great inland seas were slowly drained;
the rivers cut for themselves new chan
nels and pcrpetually diminished in vol
ume, thus forming those notable topo-
graphical markings known as terraces.
Prior to this tremendous drainage PEE
riod in cenozUic time, vast portion of
the northern continents were submerged,
either under the bordering oceans or by
broad inland seas Of fresh water. As
the continents arose the oceans retreated
toward their present limits; the wide
inland seas dwindled to comparatively
insignificant lakes; the sweeping glacial
rivers shrank to the volume of shallow
brooks, and ultimately it became pos
sible for man to dwell upon the re-
claimed and hospitable lands. Without
attempting to enumerate the marvellous
vestiges of the post-placial period in
other portions of the globe, our imme-
date surroundings in the Great Basin
contain abundant proofs of land eleva-
ton and of inter-continental drainage.
In abiding to this notable period, Pro-
fessor Dana remarks that: ''The Great
Salt Lake, which is now not over sixty
feet deep, lost nine hundred feet in
depth at this time, and contracted pro-
portionally in area; and other large
lakes in the Great Basin, and at the
eastern foot of the Sierra Nevada, lost
equally in their dimensions. The rivers
are dwindled to one tenth of their for
mcr magnitude, and become narrow
threads of water, with contracted food
grounds between wide terraced alluvial
plains, whose hmits-once their flood
limits afford ready means to the eye
of marking off the contrast" Thus it
will be seen that, during the wonderful
Champlain era, the Great American
Basin was literally tipped over, and that
its ancient aqueous treasures We're
emptiod into the neighboring Pacific