18 | GEOLOGICAL REPORT—THIRTY-FIFTH PARALLEL. 
A group of these remnants of a higher plain, forming a colonnade of sandstone so regular 
that it seemed a work of art, was sketched by Mr. Móllhausen, and I present it as a fine example 
of the effects of degradation of horizontal strata. 
COLUMNS OF SANDSTONE, SOUTH BANK OF THE CANADIAN RIVER. 
The geologist does not need to be informed of the origin of these singular mounds and 
columns of rock, but as they are objects of wonder to many travellers and excite many fanciful 
speculations, the following explanation is presented: These mounds were originally connected 
together by a continuation of their horizontal strata so as to form a plain or table-land. By 
the action of streams and drainage water, deep ravines have been excavated in various direc- 
tions, and a large part of the plain has been washed away, leaving a remnant of the strata, 
the flat-topped mounds or columns here and there. 
Gypsum.—At Camp No. 30 a bed of white gypsum, twenty-five feet thick, was found in the 
bank of the creek. It rested on sandstone and shales, and above it a bed of dolomite was seen. 
The-following is the succession of the beds, with the thickness of the exposures : 
TE doludié — .—  .. 1 7 I 6 feet 
White gypsum A 
Sandstone and argillaceous shales and red clay. .... dios 
Beyond this point, beds of gypsum 25 to 30 feet thick were found interstratified with sand- 
stone. The bed exposed in the section dips to the north at an angle of 15? near Camp 31. 
This region in the vicinity of Camps 30 and 31 appears to have been exceedingly rich in 
gypsum. The majority of the specimens in the collection are from this vicinity—from Gypsum ` 
and Comet creeks. These specimens are both red and white. See catalogue and descriptions 
Nos. 71 and 74 to 81. 
Gypsum was again found in quantity between Camps 33 and 34. It is white and rose- 
