:kel.1 
MISSOURI. 
221 
TRENTON LIMESTONE. 
DISTRIBUTION. 
The Trenton limestone occurs in two separate areas in eastern Mis- 
souri, both of which are well located with regard to railroad and 
water transportation. 
The smaller of these areas lies in Ralls, Pike, and Lincoln counties, 
the limestone outcropping as a belt 1 to 3 miles wide, commencing 
near Spalding, Ralls County, and running southeastward to Missis- 
sippi River, which it reaches at a point near Busch, about 10 miles 
south of Hannibal. From this point southward the Trenton lime- 
stone belt follows the river to near Cap au Gris, Lincoln County, 
where it turns sharply back in a northwesterly direction to within a 
few miles west of Edgewood, Pike County. 
The second and much larger belt commences in southern Callaway 
County, and runs eastward parallel to and a few miles north of Mis- 
souri River, through Montgomery, Warren, and St. Charles counties. 
This belt reaches the Missouri River at Hamburg, St. Charles County, 
and turns southeastward through St. Louis and Jefferson counties, 
reaching the Mississippi River at Kimmswick. From this point south 
to Cape Girardeau the limestone follows the river closely, appearing 
either in the bluffs or only a few miles west of them. 
COMPOSITION. 
The Trenton limestones are usually bluish to gray colored in the 
lower part, and light colored — sometimes almost white — in the upper 
part, with occasional thin beds of shale or earthy limestone between 
these two parts. As shown by the analyses in the following table, 
they are usually low in magnesia, and though occasional beds may 
show 5 to 10 per cent of magnesium carbonate the mass of the forma- 
tion may be regarded as being suitable for use as a Portland-cement 
material. 
Analyses of Trenton limestone from Missouri. a t 
Silica (SiO a ) 
Alumina ( A1 2 3 ) 
Iron oxide (Fe 2 3 ) 
Lime carbonate (CaC0 3 ) 
Magnesium carbonate 
(MgCO,) 
1 
2 
3 
4 
5 
0.35 
12.15 
2.25 
0.45 
6.00 
X .35 
.45 
.30 
.65 
1.05 
97. 75 
86.00 
89.40 
97. 20 
82. 55 
.45 
.46 
6.96 
.46 
9.27 
6 
7 
8 
9 
1.00 
0.46 
0.70 
0.35 
.55 
.40 
.25 
.30 
96.40 
98.60 
97.40 
97.75 
.42 
.34 
.42 
.27 
10 
0.55 
.60 
96. 75 
.27 
1. Dorenheiru quarry, St. Paul, St. Louis County. 
2. Thorn & Hunkin quarry, Minck station, St. Louis County. 
3. Glencoe Company, south quarry, Glencoe, St. Louis County. 
4. Glencoe Company, middle quarry, Glencoe, St. Louis County. 
5-10. Glencoe Company, north quarry, Glencoe, St. Louis County. 
a These analyses are from Bulletin No. 3, Missouri Geol. Survey, pp. 77-79, 1890. The quarries an 
named according to their owners at that date. The analyses were all made by A. E. Woodward. 
