The herald., 1894-01-11
THE SCIENCE ASSOCIATION
A Paper on the Geology of tho Sierra
Madre Mountains.


A Paper on the Geology of the Sierra
Madre Mountains.
On Tuesday evening DR.. II. A. Reid
read an exceedingly interesting paper on
the geological features of the Sierra
Madre mountains at the chamber OF
commerce hall. He gave the result Of
his personal explorations extending over
several months OF the past year. He
spoke first of the kinds of rocks. They
present nearly every variety of the gran
itic series. They consist principally of
gneiss and are composed of quartz. field
spar. horneblende and mica, the numer-
GUS quartz veins giving them a marked
striated appearance.
AS to the time and manner of uplift,
all accredited authorities agree that
they belong to the tertiary age, which
means that in geological sense they
are of comparatively recent origin.
1t was the age of mammals evolved out
of the age OF reptiles next below. In
ten years of search, however, the
lecturer had never found any fossils in
that section of the range which he
designates the Pasadena mountains ly-
ing smmediately north of the city OF
Pasadena, and up the center of which
the line OF the Mount Lowe railway ex
tends to the summit of the eliminating
peak.
Our Pasadena mountains were formed
partly by a great cataclysmal fracture
whereby the rocks on one side are tilted
up and on the other side are depressed,
and partly by the crushing together of
the rocks from contraction OF the earth's
crust in process of cooling. The crush
ing process is finely illustrated by the
fact that the rock layers all through
these mountains are not soliI, but are
all checked and cracked and scanned and
fractured at every possible angle and in
every size OF blocks from the fine breccia
to the gigantic boulder. This condition
is also partly due to earthquake vibra-
tions in connection with enormous COM
preston, and it also explains in part
why these mountains form such won
derful absorbent and etorehouee for the
water of the winter rains and SHOWS.
1t is probable that the Sierra Madres
were formed in layers beneath the
ocean from the diHintegration of older
rocks when the ocean extended to the
Sierra Nevada mountains, and had the
Majave desert for the sandy floor. They
were formed by the joint action of heat
and water. thus giving them sometimes
the appearance of aqueous and some
times of igneous rocks.
On the eastern slope OF Mt. Lowe,
near the bride road, the lecturer found
imbeded in granitic gneiss, water-worn
stone, ovoid in shape, measuring 1916
inches, and imbedded within the latter
a round interviewer pebble two inches
in diameter. He named it the geo
logical egg," for it had been hstched
into cobblestone by the mothering
waters OF UNREASONABLE time. 1t was a
part OF the Theological story of the ages.
There is a vein of auriferous quartz
extending along the south wall of these
mountains with a dip northward at an
angle of 45 degrees. There is an out
crop OF this vein in Pine cafion. the
next east Of Rubio cafion, and the Car
rie mine is being developed by E. V.
Carson and Jesse Dickey. The tunnel
starts into the face of the mountain go
feet below the outcrop and penetrates
through gnessic rotten granite. The
mine is about 5000 feet above sea level.
The same gold-bearing quartz vein crops
cut also ON Echo mountain near the
reservoir and claims have been staked.
of which one-the North Star--has
been worked to some extent. A ebaft
has been sunk following the dip of the
vein 100 feet, and tunnel has been run
at some distance below that point. Vim.
Twaddell and J. I. Best are the princi-
pal owners, but it is said that Walter
Blaine, son OF the iats Senator Blaine,
is interested in the venture. The value
of the property is as yet purely specu-
lative, but the owners seem confident OF
ultimate success.