GEOLOGICAL PAPERS II7 



Carboniferous system known as the Pennsylvanian, inasmuch as 

 it was first studied and best exemplified in Pennsylvania. The 

 drill passed through the top series (the Upper Productive), the 

 middle series (the Lower Productive) and sank about 25 feet 

 into the bottom series (the Mansfield). To differentiate between 

 these series is difficult, since they merge into each other insensibly. 

 But somewhere the line of demarkation is passed. 



Eight beds of coal (ten different layers) were encountered. 

 The top one (9 inches thick), Xo. 8 of the old geological survey, 

 is only 151 feet from the surface. The bottom one, Xo. i (4 feet 

 5 inches thick), is 555 feet from the surface. All of the beds 

 together aggregate 2;^ feet and 3 inches. 



I examined every foot of the core for limestone and found 

 eighteen dift'erent layers, varying from 6 inches to 5 feet in thick- 

 ness and giving a total of only 46 feet of limestone in the 600 feet 

 of strata penetrated. This is a small amount. 



At eighteen places the cores showed limestones by effervescence 

 in cold dilute hydrochloric acid. These sections were numbered, 

 beginning at the top. and samples taken. The beds vary from 6 

 inches to 5 feet in thickness. There is great disparity between 

 the amount of interv^ening strata. In some cases a stratum of 

 limestone of one character follows immediately below one of 

 another character. Aggin, these are far apart. For example, 

 between beds X'o. 7 and Xo. 8 are no feet of shales with no 

 intervening limestone and between Xo. 17 and Xo. 18 even a 

 greater amount. 117 feet, of shale and sandstones, totally devoid 

 of limestone. Below X'o. 7 the Upper Productive may be said 

 to end, and below X'o. 18 the Lower Productive ends. The 

 Mansfield sandstones and conglomerates begin about 40 feet 

 below the lowest coal. The distance between the beds are as 

 follows: o, 10, 9. 3. 71, 10. no. 21, 3. o. 12, 2y, 23, 40. 5. 9. 

 24. 117 feet. 



The colors are usually grey with light bluish spots, rusty, 

 brown, and black. The streak varies from white through dark 

 buff to black. All are of light specific gravity and in hardness 

 vary from 3 to 3.5. Beds Xos. i to 4, Xo. 9. and Xos. 13 and 14 

 are tough. The others are friable or fissile, like soft shale. 



One hundred milligrams of each of the eighteen were dissolved 

 in cold hydrochloric acid and after 12 hours the residues were 

 weighed. X'o. i was the most completely dissolved. The residue 

 weighed but yi of a milligram. X'o. 15 proved to be the least 

 soluble, 64 per cent remaining in the test tube. Beginning with 



