26 Report on the projected Survey of the State of Maryland. 



the spot, than it is known to have ah-eady received. But even here, 

 the occurrence of coal is a bare possibility, predicated solely npon 

 the presence of a deposite oi shale containing vegetable matter, and 

 overlaid by a conformable deposite of grey sandstone, (psammite of 

 Brongniart; gres houiller of the French,) in horizontal strata* 

 These are doubdess usual accompaniments of coal, but it does not 

 necessarily follow that where they occur, coal will always be found. 



Anthracite has certainly been discovered on the Monocacy, not 

 far from Pipe creek, in a vein running through the red sandstone. 

 The vein is represented, however, as not exceeding one or two inch- 

 es in thickness. In the sandstones at the mouth of the Seneca, the 

 undersigned detected, also very slender veins of the same mineral, 

 together with a ievi vegetable impressions. But these indications 

 only prove that the formations in which they are observed, are not 

 uncongenial to the existence of that variety of coal. 



The only part of the third geological division of Maryland that re- 

 mains to be mentioned, is the valley of Middletown, in the fork of the 

 Catoctin and South mountains. In the beauty of its position and the 

 value of its agricultural resources, it rivals the valley of Frederick- 

 town. In its geological constitution, is is found to consist of the slaty 

 and arenaceous rocks. The undersigned regret that they have as 

 yet had no opportunity of examining its mineral resources. Pyri- 

 tous copper is said to occur near Middletown ; but under what cir- 

 cumstances, and to what extent, there has been no means of ascer- 

 taining. 



The fourth geological division of Maryland falls now to be consid- 

 ered. It will be made to embrace the whole of Washington county, 

 and a part of Allegany county, as far as Cumberland. In its geolo- 

 gical structure, it consists chiefly of the slaty and arenaceous rocks of 

 the transition series, and of the limestone so well characterized by 

 the occurrence of caverns, and hence called cavernous limestone. 

 There are however found occasionally, other rocks containing the 

 impressions of shells, which afford evidence of a more recent origin. 

 The whole system of formation in a word, gradually, but more evi- 

 dently than in the preceding division, approximates to the carbonife- 

 rous groupe. The soil which covers these formations, is remarked 

 to be not so deep as in the neighboring vallies, but is very productive; 

 and the basin of which Hagerstown is the centre, between the South 

 and North mountains, together with the smaller vallies beyond, as 

 far as Hancock, are decidedly among the most fertile portions of the 

 state. But to return to its mineralogical constitution. 



