The Philipsburg mail., 1899-07-28

MT. III. A. Lee. state commissioner /
of mines for Colorado, has submitted
to the Denver Chamber of Commerce
the following facts relative to the gyp-
sum deposits of the state:
Office of the State Bureau of Mines,
Denver, Colo, June S.-Hon. John f..
Campion, President Chamber OF Com
merce, Denver. Colo: Dear Sir-ln
keeping with other resources Colorado
possesses large deposits of gypsum or
great commercial importance. At pres
ent time. nearly. if not all. the gyp-
sum products consumed in the state
are of home manufacture. Annual
production. however, is largely con-
trolled by home consumption; present
tariff rates prohibit exporting to other
states.
Preliminary to a description of a re
cent visit TO one of the gypsum quar-
ries of Larimer county, Il terse state
ment relative to the mineral itself, its
uses, etc, may prove convenient Tor
ready reference.
Gypsum is hydrous sulphate OF
lime containing when pure, sulphur
trioXide 4G.6 per cent. lime 30 and
water 900. The color, according to
purity. varies from white to gray red,
yellow, blue, brown and even black.
When calcined the water is driven off.
and in this condition it is known as
plaster of paris. Gypsum occurs trans
parent and crystallized as selenite.
tibrous as satin spar, massive and fine
ly grained as alabaster, but generally
as Il massive. dull-colored rock.
Geologically, Colorado gypsum is
characteristic Of the Juratrlas period.
and occurs in large beds in various
places, both on the east and west side
of the mountain ranges.
The chief use of gypsum is in making
plaster Of paris. which is employed for
producing a hard finish on walls,
making molds, casts of statues, med
ais, embossed ware and various 9th
er things. "Stucco plaster" is mix
ture of glue, water and calcined gyp-
sum. "PariSian cement plaster is
made of calcined gypsum and water
containing 10 per cent. bOraX. "keen's
cement" is made by mixing calcined
gypsum with One part of alum and
twelve parts of hot water. Nearly all
plaster mills make a plaster using va
riOuS compounds with the calcined
gypsum so as to retard it from 'quck
! setting" when mixed with water. and
form Il very hard plaster. The use of
this character of wall plaster has
| shown a marked increase among Colo
RADIO consumers during the past five
years. Gypsum is great fertilizer,
but as yet has been little used for this
purpose within the state.
Colorado gypsum has in the main
been formed by chemical precipitation
A 1n Of "a :
areas now containing gypsum beds
We're covered by the ocean. Following
the oscillation or elevation of the shore
line the waters retreated leaving saline
lakes of greater or less extent cut of
more or less completely from the ocean
These landlocked bodies Of salt water
would by evaporation become densely
saline and finally precipitate the va
rious salts, one after another. EXperl
ments by standard authorities go t.
show that when 80 to 40 per cent. o
ordinary sea water has been evap0l
ated, gypsum is formed, and when q
to 80 per cent. of ordinary sea watel
has been evapOrated common rock sal
begins to crystalize out. With the dep
osition of gypsum and common salt 81
closely associated. the absence of TIT
latter in connection with many of th'
Colorado gypsum beds is due to one o
two conditions, viz: Either the in
land sea waters never became cOncen
trated enough by evaporation to throw
down rock salt, or, if rock salt wa
deposited, being more soluble in waite
than gypsum, it has been removed b,
later percolating waters
Larimer county Is at present tn
largest producer of gypsum products
and Justly claims the major porto
of the output of the state for the yea
1893. The gypsum bed and mill max
ing this yield, and the only one opel
ating in the country Is located on
branch of the Colorado & SoutherI
railroad operating between Lovelan
and Atkins, at point five miles ives
Of Loveland. generally known a
Wild's Spur. Taken as a whole, Wild
Spur and surroundings are very pictur
esque. Lying to the west are the gray
colored, snow-capped mountains o
the front range, having a north an
south trend. Flanking the mountain
base are two parallel ridges or hog
backs with narrow valleys interver
ing. The ridges are made up of tn
rock-the Juratrias. Near the base @
the second ridge from the mountain
flows the Big Thompson creek. Then
level, very fertile valley. in high stat
of cultivation, threefourths Of mil
wide to point where the Dakota sane
stones rise in fold the axis of whic
IS northwest and southeast. Thes
sandstones, standing on edge or vert
cal, have better withstood erosion tina
the adjoining softer shales and clay
and are left standing alone like hug
wall twenty-five to fifty feet thick, ri'
ing in places to over 100 feet In heigf
and for a mile or more in length. Eas
of this fold is a valley or basin, ont
half mile wide, containing the gypsul
deposit.
Farther east two more ridges of tn
stratified beds of the Jura- -Cretaceor
occur, lying parallel to ridges alon
the base of mountains. With vert
? cal wall thrown diagOnally across
valley northwest and sOutheasD b
. tween two parallel ridges north an