The Saccharoidal Sandstone. — Broadhead. 105 
THE SACCHAROIDAL SANDSTONE. 
By G. C. Bkoadhkad, Columbia, Mo. 
In the Missouri geological report published in 1855 profes- 
sor G. C. Swallow divides the Lower Palaeozoic strata into a 
series of three sandstones and four limestones to which he ap- 
plies the term Magnesian limestone series, as follows, begin- 
ning at the top : 
First Magnesian limestone, 8b to 19c feet. 
First, or Saccharoidal, Sandstone, 80 to 125 feet. 
Second Magnesian limestone, 150 to 230 feet. 
Second Sandstone, 70 feet. 
Third Magnesian limestone, 350 feet. 
Third Sandstone, 50 feet. 
Fourth Magnesian limestone, 300 feet. 
With slight changes these divisions are still recognized, 
and to certain beds, local names have beeen applied. 
The Third Sandstone and Fourth Magnesian limestone 
were recognized by Swallow on the Niaugua and Osage rivers 
in Camden and Miller counties. Their equivalents may in- 
clude the lower lead-bearing limestones of Madison and St. 
Francois counties. Everywhere else they are covered with 
later sediments. The Third Magnesian limestone is well ex- 
posed on the Gasconade river in Maries and Pulaski and on 
the Osage in Cole, Miller and Morgan. It is the lead-bearing 
rock of Morgan, Miller and Washington counties. The Sec- 
ond Magnesian is the principal rock in the Missouri bluffs 
from the western part of St. Charles county to jMoniteau, and 
forms the entire hill at Jefterson city. Certain lead mines in 
Cole, Maries, Franklin and Jefferson occur in it. 
The Saccharoidal sandstone is well exposed for two miles 
along the Alississippi at and near Crystal city, 35 miles south 
of St. Louis, where a thickness of 50 feet of pure white sand- 
stone is seen. Forty miles north of St. Louis it is next seen at 
Westpoint, Illinois, and at Pacific, 35 miles west of St. Louis, 
it is well exposed. 
This sandstone wherever seen is composed of minute round 
grains of silica sometimes resembling an oolite and cemented 
by silica paste and rarely by calcite. Analysis of specimens 
from several places shows it to be over' 99 per cent of silica. 
