278 CEMENT MATERIALS AND INDUSTRY. [bull. 24 
: 
the present bulletin. It is probable that workable limestone deposits, 
other than those described below, exist in various parts of the State. 
So far as known, however, the more important limestone deposits oi( 
Oregon occur in two widely separated distiicts— in the southwestern * 
and the northeastern portions of the State. 
MATERIALS AND CONDITIONS IN SOUTHWESTERN OREGON. 
The limestones of southwestern Oregon are well developed at at 
number of points in Jackson and Josephine counties, and have been ^ 
used to a considerable extent for lime burning and flux. These lime 
stones are generally of uncertain age — some are Devonian, others most f 
likely Carboniferous, and a few certainly Cretaceous. They occur asH 
a series of lenses of greater or lesser size in the partially altered rocks J 
of the district. 
Several of these lenticular bodies of limestone outcrop in the neigh- .; 
borhood of Rock Point, on Rogue River, in Jackson County, and have! 
been extensively exploited for various purposes. A small quantity i 
has been burned locally into lime, some has been shipped to the Port-! 
land lead smelters as flux, while a larger amount has been shipped | 
to Portland and burned there into lime. Stone for building purposes 'I 
has also been derived from this series of limestone beds. 
An analysis of the Rock Point limestone, made by Mr. J. S. Phillips, •! 
follows: 
Analysis of limestone from Rock Point, Oreg. 
Silica (Si0 2 ) _ 3.1 I 
Iron oxide (Fe 2 3 ) ' 2.2 j 
Lime carbonate (CaC0 3 ) 89. 4 j 
Magnesium carbonate ( Mg00 3 ) 5. 3 j 
The belt of limestone lenses extends southwest from Rock Point, 
with several prominent outcrops on the tributaries of Applegate, 
especially on Steamboat, and on Williams Creek, where the massive 
limestone has celebrated caverns. Similar bodies occur on Sucker 
Creek, southeast of Waldo, near the California line. Their distribution 
is extremely irregular, owing to the predominance of igneous rocks. 
Very large deposits are said to occur near the California line, on Wil- 
liams Creek, in the extreme southeastern corner of Josephine County. 
MATERIALS IN NORTHEASTERN OREGON. 
Of the limestone deposits of northeastern Oregon the largest anc 
most accessible seems to be on Burnt River, about 3 miles above Hutch 
inson, Baker County. The limestone beds at this point are associatec 
with shales, and the entire series is upturned to give a steep dip. The 
river has cut through the beds, exposing a thickness of about 100 feel 
of limestone. This stone is remarkably pure, carrying usually lest 
