BIBLIOGRAPHY. 
A. 
A.bbe (Cleveland, jr.). 
L Die Fall-Linie der siidostlichen Vereinigten Staaten. 
Vierteljahrsheften fur den geographischen Unterricht. Herausgegeben von 
Prof. Dr. Heiderich, Wien, Jahrg. 2, pp. 204-210, 2 pis., 1903. 
Describes the position, and discusses the geologic, topographic, geographic, 
and historic significance of the fall line in the Atlantic coastal plain. 
ftJbercrombie (W. R.). 
L The Copper River country, Alaska. 
Franklin Inst., Jour., vol. 158, pp. 353-366, 1904. 
Includes observations on the general geology, and the occurrence of copper and 
gold ores in Alaska. 
&dams (George I.). 
L Geologj T , technology, and statistics of gypsum. 
U. S. Geol. Surv., Bull. no. 223, pp. 12-32, 6 pis., 1 fig., 1904. 
Includes a short discussion of the origin and geologic age of gypsum deposits 
in general. 
Zinc and lead deposits of northern Arkansas. 
U. S. Geol. Surv., Professional Paper no. 24, pp. 1-89, 27 pis., 6 figs., 1904. 
Describes physiographic features briefly, the occurrence and character of 
Ordovician, Devonian, and Carboniferous formations, the geological history 
and structure, and the occurrence and origin of the zinc and lead ore 
deposits of this region. 
>. Zinc and lead deposits of northern Arkansas. 
Am. Inst. Mg. Engrs., Trans., vol. 34, pp. 163-174, 1904. 
See no. 8 of the Bibliography for 1903, U. S. Geol. Surv., Bull. no. 240. 
. The Rabbit Hole sulphur mines near Humboldt House, Nev. 
U. S. Geol. Surv., Bull. no. 225, pp. 497-500, 1904. 
General geology and occurrence and origin of the sulphur. 
kdams (George I.), Haworth (Erasmus), and Crane (W. R.). 
. Economic geology of the lola quadrangle, Kansas. 
U. S. Geol. Surv., Bull. no. 238, 83 pp., 11 pis. and 13 figs., 1904. 
Describes the general character and areal geology of the area, the character, 
occurrence, and relations of the Carboniferous formations, the geologic 
structure of the field, and in detail the occurrence, character, and origin of 
the natural gas and petroleum, and their utilization in the manufacture of 
cement, brick, and zinc spelter. 
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