40 THE CAMBRIAN AND ORDOVICIAN DEPOSITS OF MARYLAND 



WALCOTT, C. D. Correlation Papers Cambrian. 

 Bull. U. S. Geol. Surv., No. 81, 1891. 

 House Misc. Doc., 52d Cong., 1st sess., vol. xx, No! 25. 



Based chiefly on Tyson's Repqrt, pp. 133, 287, 290. For problems unsolved see 

 pp. 328-383. 



1892 



KEITH, ARTHUR. The Geologic Structure of the Blue Ridge in Mary- 

 land and Virginia. 



Amer. Geol., vol. x, 1892, pp. 362-368. 



Broadly considered, the region is an anticline, where an arch is crumpled into 

 several synclines and broken by faults till the resultant structure is quite complicated. 



LESLEY, J. P. A Summary description of the Geology of Pennsylvania. 

 3 vols. Harrisburg, 1892. 



Numerous references to formations passing southwards into Maryland. 



WALCOTT, C. D. The Geologist at Blue Mountain, Maryland. 



Nat. Geog. Mag., vol. 5, 1892, pp. 84-88. 



Sci. Amer. Supp., vol. 37, 1892, pp. 14753-14754. 



. Notes on the Cambrian Rocks of Pennsylvania and Mary- 

 land from the Susquehanna to the Potomac. 



Amer. Jour. Sci., 3d ser., vol. xliv, 1892, pp. 469-482. 



The portion of Maryland studied lies in the Blue Ridge and Catoctin mountains from 

 Mechanicstown (Thurmont) to Monterey, Pa., along the W. M. R. R. and southward to 

 Harper's Ferry, W. Va. 



1893 



WILLIAMS, G. H. (The Appalachian Region and the Itinerary from 

 Washington, D. C., to Cumberland, Maryland.) 



Geological Guidebook of the Rocky Mt. Excursion, Compte Rendu de la 5me 

 Ses. Congres Geolog. Internat. Washington, 1893, pp. 268-279. 



House Misc. Doc., 53d Cong., 2d sess., vol. xiii, No. 107, pp. 268-279. 



Summary of the local geology along the route. 



WILLIAMS, G. H., and CLARK, W. B. Geology of Maryland. 



Maryland, its Resources, Industries and Institutions, Baltimore, 1893, 

 pp. 55-89. 



A general summary of the geology of Maryland with many illustrations and local 

 references. 



WILLIS, BAILEY. The Mechanics of Appalachian Structure. 



13th Ann. Rept. U. S. Geol. Surv., 1891-92, pt. 2, Washington, 1893, pp. 211-281, 

 plates and maps. 



The discussion includes illustrations from Maryland, and its conclusions are appli- 

 cable to the western portion of the state. 



