BIBLIOGRAPHY OF NORTH AMERICAN GEOLOGY, L906-1907. 193 
Warren, Charles H. 
2478. The minera logical examination of sands.— Tech. Quart., vol. 19, no. 4, 
pp. 317-338, 1906. 
Gives an account of the methods employed to examine sands for minerals and of the 
characters of the minerals found. 
On yttrocrasite, a new yttriuni-thorium-nranium titanate. — See Hidden and 
Warren, no. 1143. 
Warwick, A. W. 
2479. Notes on mining conditions in and a section across the Sierra Madre 
Mountains in Mexico. — Colorado Sci. Soc, Proc, vol. 8, pp. 123-156, 5 pis., 1906. 
Includes data upon the geologic structure of the Sierra Madre and the occurrence and 
character of the rocks, mainly of volcanic origin. 
2480. Topographical and other notes on the Choix-Guadalupe y Calvo mining 
districts [Mexico]. — Min. and Sci. Press, vol. 95, pp. 686-688, 2 figs., November 
30, 1907. 
Includes notes on the geology. 
Washburne, Chester W. 
2481. Thomas Condon.— Jour. Geology, vol. 15, no. 3, pp. 280-282, 1907. 
Gives a brief account of his life (1822-1907) and a list of his writings. 
Washington, Henry S. 
2482. The formation of leucite in igneous rocks. — Jour. Geology, vol. 15, 
pp. 257-279, 357-395, 3 pis., 1 fig., 1907. 
The texture of igneous rocks. — See Cross, Iddings, Pirsson, Washington, 
no. 608. 
Contributions to the geology of New Hampshire : no. II, Petrography of the 
Belknap Mountains. — See Pirsson and Washington, no. 1934. 
Occurrence of diamonds in Arkansas. — See Kunz and Washington, no. 1444. 
Note on the forms of Arkansas diamonds. — See Kunz and Washington, no. 
1445. 
Washington, University of. 
The School of Mines series of rock specimens from the State of Washington. — 
See Roberts, Milnor, and others, no. 2071. 
Watson, Thomas Leonard. 
2483. A preliminary report on the ocher deposits of Georgia. — Georgia Geol. 
Survey, Bull. no. 13, 81 pp., 11 pis., 2 figs., 5 maps, 1906. 
Describes the stratigraphy and geologic structure of the Cartersville district, the geo- 
graphic distribution, geologic position, and genesis of the ocher deposits, the composition 
and physical properties of the ocher, and the economic developments. 
2484. Bead and zinc deposits of the Virginia-Tennessee region. — Am. Inst. 
Min. Bug., Trans., vol. 36, pp. 681-737, 29 figs., 1906 (Bi-Mo. Bull., no. 8, pp. 
139-195, 29 figs., March, 1906). Abstract: Mines and Minerals, vol. 27, pp. 
17-19, 63-65, 3 figs.. 1906. 
Describes the general geology of the region, the distribution of the ore deposits, and the 
alteration, mode of occurrence, and origin of the ores. Adds a bibliography. 
2485. Lithological characters of the Virginia granites. — Geol. Soc. America,. 
Bull., vol. 17, pi.. 52:5-540. 4 pis., 7 tigs.. 1906. 
Describes the distribution and lithologic characters of various typos of granite occurring 
in the Piedmont region of Virginia. 
2486. Occurrence of unakite in a new locality in Virginia. — Am. Jour. Sci., 
4th ser., vol. 22, i>. 248, September, 1906. 
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