228 Geology of the Country between 



along the road, we find limestone quarried as a flux for some iron 

 works close at hand. The mountain itself is a coarse quartzose grit, 

 almost a conglomerate, overlaid with finer sandstone and lastly a soft 

 slate or shale. The limerock near the furnace lies on the slate and 

 is covered by similar slate that continues in sight along the road to- 

 wards Laudisburg. The slate is very soft, rapidly disintegrates and 

 as usual of various colors, grey, blue, green and red. In the vicinity 

 of Harrisburg, Pa. the same order of superposition may be observed, 

 although not within so small a compass. This view of the position 

 of our limestone strata, agrees with observations made at other points 

 on our continent, where similar deposits exist, and also with the views 

 of many foreign geologists. By reference to the section prefixed to 

 Prof. Eaton's canal survey, I find between Williams College and the 

 top of Peterboro' mountain, the following alternations; limerock, ar~ 

 gillite, limerock, argillite, calc sandrock, limerock, graywacke*- 

 Three distinct alternations of transition limerock, with what I consider 

 different members of the transition graywacke formation, occur with- 

 in a very short distance. The author also observes, that " the spar- 

 ry limerock is found, geologically lower as well as higher, than the ar- 

 gillite of Williamstown mountain range. 55 * Prof. Hitchcock in speak- 

 ing of the same region, says that the Berkshire limestone, after being 

 traced eastward through West Stockbridge, Mass. and Chatham, 

 N. Y. "is probably interstratified with graywacke slate, in Rensse- 

 laer and Columbia counties, N. Y. 55 f Dr. Hayden of Baltimore,! 

 noticed the same alternation a few miles south of Bedford, Pa. al- 

 though he does not appear to have considered the superimposed sand- 

 stone as being in place. It seems to me rather probable, that it was 

 in place, as I have myself observed alternations of sandstone and 

 limerock, along the road a few miles east of Bedford. Dr. H. al- 

 so observes "the whole region, however may, I believe, be consider- 

 ed as secondary. 55 But if my observations are correct, that imme- 

 diate vicinity, cannot be considered as secondary, according to those 

 observations. Transition graywacke occurs directly east of Bed- 

 ford, the town itself stands on a dark blue transition limestone, and 

 the secondary country does not begin until several miles west of 

 Bedford. I am unable to say how many miles exactly, as a matter 

 of opinion I would say, less than twenty. Bakewell remarks, that 

 " transition limestone occurs in beds alternating with slate, graywacke, 



* Canal survey, p. 59. t Report on Geology, & c . of Massachusetts, p. 304. 



t See American Journal of Science, Vol. xix, p. 97. 



