200 ANALYSES OF ROCKS AND MINERALS, 1880-1908. 
T. Ferruginous dolomite, Hamburg Hill, Menominee district, Michigan. De- 
scribed by Bayley in Mon. XLVI, p. 480. Analysis by George Steiger, record No. 
2033. 
27. 05 | 72.51 | 100.11 
The three following analyses, by E. C. Sullivan, record No. 2160, are of material 
collected in Michigan by I. C. Russell. 
U. Marl, Ore Lake. 
V. Dolomite, Maybee, tenth layer from top. 
W. Like V, fifth layer from top. 
U Vv. Ww. 
BiQes cece seceniekdee te eionnecanness yosauyewesre tea eure snntke asin eeerednremeains ae 0. 53 1.77 1.30 
AlOs.- 14 -01 16 
Fe203¢ 96 41 
MgO 1.10 | 20.84 19.79 
CaO 51.87 | 29.65 31.14 
Na2O0 ee “AO esemepedsemaieces 
Teg Oicpme ase See tite ee Bae wick: wibhioemeatnre ace dO, sen aes eam ses 
Eg Qv at WG ica; ois cievse aici: uetes ress sects silenced aes arcs 97 -12 «18 
H20 above 105°... .....- ares piss sigs apse raison sins 1,22 - 48 .57 
CO diss, ssjeysisisie sia cis s eperereretaiete etal us Ftsisseia come raceestasi is ntsinisvaveretaoeaes -.-| 42.30] 46. 40 45. 18 
@ Total iron. 
SOUTH DAKOTA AND WYOMING. 
A. Purple limestone, east of Cascade, Black Hills, South Dakota. Collected by 
G. B. Richardson. Analysis by George Steiger, record No. 1854. 
B. Dolomite from the Tornado mine, Black Hills. Received from 8S. F. Emmons. 
Analysis by W. F. Hillebrand, record No. 1866. 
