MARYLAKD GEOLOGICAL SURVEY 197 



river at Port Deposit by the Port Deposit Bridge Company. During 

 the process of construction the abutments for the eastern approach 

 were made from stone quarried at the eastern end of the bridge, 

 which is within the present corporate limits of the town of Port 

 Deposit and not far from the site of the McClenahan quarries. For 

 about ten years the opening so made was worked in a small way by 

 Mr. Simon Freeze, who had supplied the materials used in the con- 

 struction of the bridge. In 1829 the owners of the Maryland canal 

 became interested in the quarry, and increased its workings. In 

 1830 the business passed into the hands of Messrs. Samuel Megredy 

 and Cornelius Smith, who still further increased the scope and opera- 

 tions, and developed a considerable trade with Baltimore and other 

 coastwise towns. Two years later Mr. Ebenezer D. McClenahan 

 became interested in the granite quarrying industry through his 

 brother-in-law Mr. Daniel Megredy, who was then a successful opera- 

 tor. McClenahan became the dominant factor in the local devel- 

 opment and gradually increased the business until in 1837, from 

 data furnished by Anthony Smith, Ducatel 1 estimated the annual 

 output at from 12,000 to 15,000 perches. On the retirement of Mr. 

 E. D. McClenahan the business was transferred to his sons, who are 

 at present the principal owners in the Port Deposit company. 



The quarries at Port Deposit are in rocks of igneous origin, which 

 have been variously modified by severe dynamic action. This has 

 produced a certain degree of schistosity which causes the Port Deposit 

 granites to be taken at times for gneiss rather than granite. This 

 foliation which is produced by the parallel arrangement of the black 

 mica flakes has a northeasterly trend nearly at right angles to the 

 course of the river and a dip that is almost vertical. There is no 

 marked banding in the rock, but the whole face of the quarry, which 

 shows thousands of feet of surface, appears perfectly homogeneous, 

 as though made up of a single rock. Through this mass there now 

 pass several series of intersecting joints of which the most prominent 

 approximately coincides with the northeast trend of the foliation, but 

 which inclines somewhat to the dip of the foliation. A second set 



1 Ann. Rept. of the State Geologist of Maryland, 1837, p. 15. 



