110 GEOLOGY. 



4. AMERICA. 



Allen, J. A. Metamorphism produced by the burning of Lignite 

 Beds in Dakota and Montana. Boston. 



Andrews, E. B. On the parallelism of Coal-seams. Amer. Journ. 

 sor. 3, vol. viii. pp. 56-59. 



A rejoinder to Dr. Newberry's critique [see p. 125], in which the 

 writer adheres to his belief in general and well-marked parallelism of 

 coal-seams, *' such as makes the stratigraphy of our coal-fields a system 

 of symmetry and beauty." He does not believe in the theory of un- 

 equal subsidences &c. Gr. A. L. 



Anon. Corundum. Popular- Science Monthly, Feb., New York. 



Account of Col. Jenks's researches respecting the Corundum veins of 

 North Carolina. 



. Cave at Kutztown, Berks Co., Pa. Amer. Journ. ser. 3, 



vol. vii. p. 77. 



Note announcing the discovery of this stalactitic cave. 



. Note on the Geology of Costa Rica [letter]. Amer. Journ. 



ser. 3, vol. vii. pp. 438, 439. 



The sedimentary rocks of the Atlantic slope of Costa Rica, usually 

 highly metamorphosed, are certainly Tertiary; the writer is further 

 convinced that they are Eocene. Wherever dykes cut up the meta- 

 morphic shale and sandstones, auriferous quartz-veins occur, and placer 

 deposits exist in most of the streams that run from the margins of the 

 volcanic belt. G. A. L. 



. Lake-Superior Iron Mines. Coll. Guard, vol. xxviii. p. 532. 



Note from the U.S. Railroad and Mining Register. This great iron- 

 region lies 12 to 30 miles back from Marquette, and reaching into Wis- 

 consin, a distance of 150 miles. The ores are chiefly specular, brown 

 haematites, and magnetic. G. A. L. 



. Coal and Iron in California. Coll. Guard, vol. xxviii. p. 533. 



Note from the Journal of Commerce (U.S. ?) announcing the discovery 

 of vast coal-deposits on the line of the lone railroad, and of the exis- 

 tence of iron-deposits in the same direction. G. A. L. 



Ansted, Prof. D. T. Account of a recent visit to the Coal and Iron 



Fields of Virginia. Journ. Soc. Arts, vol. xxii. pp. 182-188 ; see 



also no. 1107, p. 230, and Coll. Guard, vol. xxvii. pp. 180, 181. 



The iron-ores are of two kinds and in two geological positions. East 



of the Blue Ridge there are bands of magnetite ranging N.E. and S.W., 



and ridges with cores of compact rich ore (chiefly peroxide) ; west of 



the Blue Ridge, in the valley that extends towards the Appalachians, 



there are contorted Silurian and Devonian rocks with, at intervals, a 



band of brown haematite and a thinner bed of rich peroxide. In many 



cases limestone-bands alternate with the ironstone. The coal-seams 



