MARYLAND GEOLOGICAL SURVEY -65 



utilized for lime and ballast is at Cavetown, where good location and 

 transportation facilities are at hand. 



The marbles of the Tomstown were formerly quarried to a considerable 

 extent, especially in the southern part of the area, but at present the only 

 development is near Eakles Mills. White marbles which occur at several 

 horizons in the formation, have been most frequently quarried. With 

 these is a bed of a cream-white color with a very fine texture, but the 

 associated beds are impure and have the more usual grayish banded 

 appearance. The pinkish shaly marbles likewise include some pure white 

 beds which might be profitably quarried if transportation facilities were 

 available. An abandoned quarry, situated on the bank of Beaver Creek, 

 one mile northeast of Harmony Hill school, gives a good exposure of these 

 light colored marbles. 



AREAL DISTRIBUTION. The outcrops of the Tomstown limestone are 

 confined to the eastern part of the Hagerstown Valley just west of the 

 Blue Eidge in a belt of low land at the foot of South Mountain about two 

 miles wide in the northernmost portion, increasing to a width of three 

 miles or more southward. Along the entire eastern border of the forma- 

 tion the Harpers shale is faulted against this limestone with the inter- 

 vening formation, the Antietam sandstone, either wanting or outcropping 

 some little distance east of the Tomstown as an infold in the shale. The 

 western border of the Tomstown limestone in northern Maryland as far 

 south as the Western Maryland Eailway is the normally overlying 

 Waynesboro formation. South of this, the Tomstown is faulted first 

 against the Elbrook formation, then against the Conococheague limestone 

 as at Chewsville, then against the Elbrook again for some miles, and 

 finally at Benevola on the National pike, the succession becomes normal 

 again. A fault passing north and south just east of Boonsboro parallels 

 South Mountain and along its western side several small areas of Waynes- 

 boro are exposed. West of this fault in the middle of the Tomstown 

 valley the line of hills starting a mile north of Smithsburg and ending 

 near Beaver Creek are formed by an infolded area of the Waynesboro 

 formation. With these exceptions and several small areas where the 



