Part I. Report of progress in 1869, by J. S. Newberry, chief geologist. Part II. Report of progress in the second district, by E. B. Andrews, assist. geologist. Part III. Report on geology of Montgomery County, by Edward Orton, assist. geologist.

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B. Clinton Limestones.
1. From Brown's Quarry,* New Carlisle, Clarke county.
Carbonate of lime........................................................ 95.60
Carbonate of magnesia............................... 3.93
Alumina and iron........................................................ 0.40
99.93
2. From Centerville, Montgomery county.
Carbonate of lime.......................................... 86.30
Carbonate of magnesia.................. 11.34
Silica.............................................................. 0.86
Alumina and iron....................................................... 0.40
98.89
3. From Halderman's Quarry, t Eaton, Preble county.
Carbonate of lime.................................................. 85.21
Carbonate of magnesia..................................... 13.56
Silica.................................................................. 0.35
Alumina and iron, chiefly iron................................ 0.80
99.92
4. From Lick Fork, Adams county, "Flinty Limestone," of Locke.
Carbonate of lime................ 93.00
Carbonate of magnesia.............................. 3.04
Silica and sand......................................................... 2.00
Alumina and iron........................................................ 1.60
99.64
C. Niagara Group.
1. From Dayton Quarries. (Dr. Locke, 1835.)
Carbonate of lime.................................... 92.40
Carbonate of magnesia................................... 1.10
Matter insoluble in muriatic acid.................................. 1.70
Protoxide of iron......................................................... 0.53
Silex from solution.............................................. 0.90
Water expelled by red heat.............................. 1.08
97.71
II. MAGNESIAN LIMESTONES- CONTAINING 40 PER CENT. OR MORE OF
CARBONATE OF MAGNESIA.
1. From Yellow Springs-Sroufe's Quarries.
Carbonate of lime....................................... 54.75
Carbonate of magnesia................................................... 42.23
Silica.................................................................... 0.40
Alumina and iron................................................. 2.00
99.38
* This is the purest lime found in south-western Ohio.
t This is one of the divisions of the Clinton which has a local reputation as a fire
stone.