346 Tlie Aiiicrican Geologist. Juue, isos 
.bm/ysis of Arizona Aftthracite. 
No. Sp. Itr. Ash. Combustible 
and water. 
1 1.49 13.20 86.80 Selected fra.tjments. 
2 1.73-1.80 30.45 69.55 
3 1.76 27.40 72.60 Slaty. 
4 1.85 30.00 70.00 " 
5 22.04 77-96 Black powder. 
No. I, had red ashes; No. 2, white ash; No. 3, white ash, 
tinged with red; No. 5, red ash. All the beds afford glossy 
black htstrous and shining masses, but generally in curved 
layers, and having a graphitic luster, except Nos. i and 5. 
No. 5 is taken out of the mine in a fine black powder. 
It cannot be claimed that any of this material has much 
value as a fuel. It may be foimd useful in some metallurgical 
operations as a deoxidizing agent, or for lining (brasqueing) 
crucibles and furnaces. 
The presence of such large beds of carbonaceous material is 
significant of a great area of Palaeozoic vegetation and of shal- 
low seas and coal-forming basis analogous to those of the Coal 
Measures. If, as I confidently expect, further investigation 
shall show that these graphitic anthracites are metamorphised 
coal-beds of Carboniferous age, our present ideas of the west- 
ward extension of the flora of that period will require great 
modification. 
There are many evidences in southern Arizona of shallow 
seas in Paleozoic time, and of great tidal currents, and of ex- 
tensive shore-lines. Coarse conglomerates of well-rounded 
pebbles of Palaeozoic age abound in the Santa Ritas, in the 
Santa Catalinas, in the Babioquirari and other moimtain 
ranges, and in the low hills of Arivaca, south of Tucson and 
near the boundary of Mexico. 
Quartzytes — probably Cambrian — are a striking feature 
of sonle of the mountain ranges between Tucson and the gulf 
coast of Sonora. 
CARBONIFEROUS FORMATIONS OF 
SOUTHWESTERN IOWA. 
By Charles R. Keyes, De.s Moines, Iowa. 
For nearly half a century it has been known that the south- 
western part of Iowa is occupied by "upper coal measures." 
