LOBECK, NEW YORK CITY, A PHYSIOGRAPHIC CEXTER 43 



VII. — Older Appalachians Province 



147. Barrell, J. 1913. Terraces of northern Appalachians. Bull. Geol. Soc. 



Am.. XXIV, p. 688. 



148. Bascom, F. 1893. South mountain structure. Jour. Geol., I, p. 813. 



149. Bascom, F. 1896. Volcanic rocks of South mountain, Pa. Bull. U. S. 



G. S., No. 136. 



150. Bascom, F. 1905. Piedmont of Pennsylvania. Bull. Geol. Soc. Am.. 



XVI, p. 289. 



151. Darton, X. H. Economic geology of Richmond. Bull. U. S. G. S., No. 483. 



152. Eaton, H. X. 1912. Geology of South mountain, Pa. Jour. Geol., XX, 



p. 331. 



153. Geiger, H. R., and Keith, A. 1891. Structure of Blue Ridge near 



Harpers Ferry. Bull. Geol. Soc. Am., II, p. 155. 

 *154. Keith, A. 1893. Catoctin belt. 14th Ann. Rept. U. S. G. S., Part 2, p. 

 285. 

 155. Mathews, E. B. 1905. Maryland and Pennsylvania Piedmont. Bull. 

 Geol. Soc. Am., XVI, p. 329. 

 *156. McGee, W J. 1896. Geographic history of Piedmont plateau. Xat. Geog. 



Mag., VII, pp. 96, 261. 

 157. McGee, W J. 1898. Geographic development of District of Columbia. 



Xat. Geog. Mag., IX, p. 317. 

 *158. Shaler, X. S., and Woodworth, J. B. 1898. The Richmond (triassic) 



basin. 19th Ann. Rept. U. S. G. S., Part 2, p. 385. 

 159. Shaler, X. S. 1899. Spacing of rivers with reference to hypothesis of 



baseleveling. Bull. Geol. Soc. Am., X, p. 263. 

 *160. Surface, G. T. 1906. Physiography of Virginia. Bull. Am. Geog. Soc, 



XXXVIII, p. 741. 

 *161. Tower. W. S. 1906. Regional and economic geography of Pennsylvania. 



Bull. Geog. Soc. Phila., IV, pp. 9, 113, 193, 271 ; V, p. 21. 

 162. Williams, G. H., and Keyes, C. R. 1891. Piedmont of Maryland. Bull. 

 Geol. Soc. Am., II, p. 301. 

 *163. Harpers Ferry Folio, U. S. G. S., Xo. 10. 

 164. Fredericksburg Folio, U. S. G. S., Xo. 13. 

 *165. Washington Folio, U. S. G. S., Xo. 70. 

 *166. Philadelphia Folio, IT. S. G. S., 162. 

 *167. Trenton Folio, U. S. G. S., Xo. 167. 



VIII. — Coastal Plain Province 



*168. Abbe, C, Jr. 1899. Physiography of Maryland. Md. Weather Service. 



I, p. 41. 

 169. Clark, W. B. 1897. Upper cretaceous of Xew Jersey, Delaware, and 



Maryland. Bull. Geol. Soc. Am., VIII, p. 315. 

 *170. Clark and Mathews. 1906. Physical features of Maryland. Md. Geol. 



Surv., Spec. Pub., Vol. VI (with geol. map). 



171. Darton, X. H. 1896. Artesian well prospects in Atlantic coastal plain. 



Bull. II. S. G. S., No. 138. 



172. Darton, N. H. 1911. Economic geology of Richmond. Bull. U. S. G. S., 



No. 483. 



