:kel. j 
INDIANA. 
139 
KNOBSTONE GROUP. 
The lowest member of the Mississippian is the Knobstone group, 
his is about 400 feet in thickness, and is made up of shales arid shaly 
ndstones. The Knobstone series is of interest in the presenl connec- 
on because the shale used at one of the Portland-cement plants of 
te State is derived from it. 
COMPOSITION. 
The composition of the Mississippian limestones of Indiana is shown 
r the following analyses: 
Analyses of Mississippian limestones from Indiana, a 
No. 
Silica (SiO.,). 
0.50 
.70 
1.74 
1.60 
.65 
.90 
1. 13 
.31 
.48 
.84 
.86 
.64 
.76 
1.26 
1. 69 
.63 
.15 
.50 
Alumina 
(A1 2 3 ), 
iron oxide 
(Fe 2 3 ). 
0.98 
.91 
.29 
. is 
1.00 
3.00 
1.06 
.32 
.15 
.13 
.16 
.15 
.15 
.18 
.49 
.39 
.64 
.71 
Lime carbon- 
ate i CaC0 3 ). 
96. 60 
96. 7!) 
95. 62 
95. 55 
95. 54 
95. 00 
96. 04 
US. (Ml 
98.91 
97. 39 
98.11 
98.27 
98. 16 
97. W 
97.26 
98.20 
93. 80 
113.07 
Magnesium 
carbonate 
(MgCOs). 
0.27 
.23 
.89 
.93 
.40 
.22 
.63 
.78 
.92 
.84 
.97 
.65 
. 77 
.81 
4.01 
4.22 
I. Chicago and Bedford Stone Company, Bedford, Lawrence County. Indiana Geol. Surv., LSTs, 
95. 
Simpson and Archer quarry, near Spencer. Ibid., p. 94. 
4, "). Dunn & Co., Blooming"ton. Twenty-first Rept. Indiana Dept. Geo 1 .., p. 320. 
Monroe Marble Company, Stinesyille. Indiana Geol. Rep., 1862, p. 137. 
Salem. Idem, 1886, p. 144. 
Stockslager quarry, Harrison County. Idem, 1878, p. 96. 
Milltown. W. A. Noyes, analyst. Twenty-seventh Rept. Indiana Dept. Geol., p. 98. 
10. Acme Bedford Stone Company, Clear Creek, Monroe County. Twentieth Ann. Rept. T T . S. < leol. 
irvey, pt. 6, p. 381. 
II. Hunter Brothers' quarry, Hunter Valley. W. A. Noves, analyst. Twenty-first Rept. Indiana 
l>t. Geol., p. 320. 
12. Indiana Stone Company, Bedford, Lawrence County. W. A. Noyes, analyst. Ibid. 
13. Twin Creek Stone Company, Salem, Washington County. W. A. Noyes, analyst. Ibid. 
14. Romona Oolitic stone Company, Etomona, ( Iwen County. W. A. Noyes, analyst, [bid. 
15-16. Hoosier Stone Company, Bedford, Lawrence County." F. W. Clarke, analyst. Bull. U. S.Geol. 
irvey No. 42, p. 140. 
17-18. Indiana Steam Stone Works, Big Creek. L. H. Streaker, analyst. Tuentv liist Rept. Indiana 
?pt. Geol., p. 320. 
"These analyses are mostly of the Bedford limestone. 
