142 BIBLIOGRAPHY OF NORTH AMERICAN GEOLOGY, 1906-1907. 
Obalski, J. — Continued. 
1812. New discoveries in northern Quebec. — Eng. and Min. Jour., vol. 83, 
p. 559, March 23, 1907; Canadian Min. Jour., vol. 28, no. 4 (new ser., vol. 1, 
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Calls attention to discoveries of mineral deposits. Includes notes on the geology. 
1813. Rare earths in pegmatite veins. — Can. Min. Inst., Jour., vol. 9, pp. 
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Offret, A. 
1814. El X congreso geologico internacional en Mexico. — Mexico, Secretaria 
de Fomento, Bol., 2 a epoca, alio 7, no. 1, VI, pp. 1-48, August, 1907. 
Gives an account of the Tenth International Geological Congress, held in Mexico, 1906. 
O'Harra, C. C. 
Description of the Devils Tower quadrangle, Wyoming. — See Darton and 
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Ogilvie, Ida H. 
1815. A contribution to the geology of southern Maine.— New York Acad. 
Sci., Annals, vol. 17, pt. 2, pp. 519-558, 2 pis., 2 figs., 1907. 
Describes the physiographic features of Boothbay quadrangle, and the character, 
occurrence, and composition of the igneous rocks and their metamorphism. 
Ohern, D. W. 
1816. Contributions to the paleontology of the Paleodevonian of Maryland. — 
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Omori, Fusakichi. 
1817. Note on the San Francisco earthquake of April 18, 1906. — Publications 
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21, Appendix II, 3 pp., 1 pi., Tokyo, 1906. 
1818. On the great earthquake of April 18th, 1906, of San Francisco. — 
Jour. Geog. (published by the Tokyo Geog. Soc), vol. 18, no. 215, pp. 764-777, 
November, 1906. [In Japanese.] 
1819. On the estimation of the time of occurrence at the origin of a dis- 
tant earthquake from the duration of the first preliminary tremor observed at 
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Includes lime data regarding the San Francisco earthquake of April 18, 190G. 
1820. Preliminary note on the cause of the San Francisco earthquake of 
April IS, 1906. — Imperial Earthquake Investigation Committee, Tokyo, Japan, 
Bull., vol. 1, no. 1, pp. 7-25, 6 pis., 9 figs., January, 1907. See also Jordan, 
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1821. Preliminary note on the seismographic observations of the San Fran- 
cisco earthquake of April 18, 1906. — Imperial Earthquake Investigation Commit- 
tee, Tokyo, Japan, Bull., vol. 1, no. 1, pp. 26-43, 6 pis., January, 1907. 
Tabulates seismographic records of the San Francisco earthquake made at various 
earthquake observation stations and discusses the rate of transmission. 
1822. Note on the transit velocities of the Guatemala earthquake of April 
19, 1902. — Imperial Earthquake Investigation Committee, Tokyo, Japan, Bull., 
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1823. Comparison of the faults in the three earthquakes of Mino-Owari, 
Formosa, and San Francisco. — Imperial Earthquake Investigation Committee, 
Tokyo, Japan, Bull., vol. 1, no. 2, pp. 70-72, 1 fig., March, 1907. 
