56 THE CAMBRIAN AND ORDOVICIAN DEPOSITS OF MARYLAND 



making formation of the Blue Eidge province. Elk Eidge, South Moun- 

 tain, and Catoctin Mountain are the principal elevations in Maryland 

 due to the resistant Weverton sandstone and it is along their crests that 

 the formation is exposed. Sugar Loaf Mountain is the easternmost eleva- 

 tion due to this formation. 



This sandstone is composed almost entirely of siliceous fragments, 

 mainly quartz and feldspar, firmly cemented together and often changed 

 into quartzite. The color of the finer sandstone is white, and the coarser 

 gray to purple. Streaks of bluish black and black sometimes occur in the 

 white sandstone on South Mountain. Feldspathic material is present in 

 greatest abundance at the northern end of Catoctin Mountain, but its 

 occurrence does not change the general aspect of the formation. As a 

 rule, however, the Weverton is usually composed of well-worn quartz 

 grains washed clear of argillaceous material. Cross bedding is not an 

 uncommon occurrence. 



As the quartz particles forming the main mass of the Weverton sand- 

 stones do not admit of much alteration, this formation has been subjected 

 to comparatively little metamorphism, even when it has been greatly 

 folded. Slight schistosity has been noted in the southern part of Catoctin 

 Mountain, but the development of quartzite is the usual occurrence. 



The Weverton sandstone varies little in composition from place to place, 

 but the thickness is subject to much variation. Along Elk Ridge its thick- 

 ness is about 500 feet. At the type locality near Weverton, the thickness 

 is also about 500 feet, but northward along South Mountain this increases 

 to 800 feet. A similar increase in thickness is seen in the Catoctin 

 Mountain area. 



This formation is not only of no value agriculturally, but the debris 

 from it lessens the value of neighboring areas. It decays very slowly into 

 quartz sand and its heavy blocks cover the mountain sides and the con- 

 tiguous lowlands. The mountain streams carry great quantities of 

 boulders of Weverton sandstone out on the surrounding areas where they 

 are deposited as a drift formation not unlike glacial deposits. South 

 Mountain has furnished boulders of white quartzite and sandstone, which 



