278 GEOLOGY OF OHIO 



bodies with reference to future mining enterprises. Qne or two mines for ' 

 the general market have been added to tnose named in Volume V, which 

 are still extensively worked. 



None of the coal seams thus far named have been included in the 

 maps of Volume VII. But the map of Jackson and Vinton counties, ac- 

 companying Volume V, gives the main boundary and also the outliers of 

 the Ferriferous limestone. This map would answer almost equally 

 well for the "limestone coal." 



The Kittanning Group. 



3. The Lower Kittanning Coal. This is a fairly wide-spread seam and 

 is accordingly known by many local names. It is Coal No. 5 of New- 

 berry, from the Tuscarawas Valley, westward and southward. It is Coal 

 No. 3 of the same author in the Ohio Valley, where it is also known as 

 the Clay Vein coal. It is the Lower Zanesville and the Lower New Lex- 

 ington coal of Andrews, and the Newcastle coal of Lawrence county. It 

 is also the Washingtonville or Letonia coking coal. ■ 



The Lower Kittanning coal may be said to be included in the first 

 main boundary of the maps that accompany this volume. The boundary 

 is referred to the Middle Kittanning seam only, in the legend of the maps; 

 but as the two seams are only twenty to thirty feet apart in the region 

 of their best development, their outcrops, where both seams are present, 

 are practically identical. There are a few localities, in which outliers of 

 the Lower Kittanning coal maintain themselves beyond the margin of the 

 Middle Kittanning coal seam for a mile or two. But even in such cases 

 nothing is really sacrificed of economic value in counting the boundaries of 

 the two seams identical, because the coal of the outliers is generally under 

 so thin cover as to be worthless. The frequent absence of the lower coal 

 forbids us to introduce its name in the description upon the map. 



The practical developement of the Lower Kittanning coal remain? 

 about the same as the date of the issue of Volume V. There is less 

 rather than more mining done in this seam at present than there was 

 ten years ago. 



4. The Middle Kittanning Coal. The seam now reached is, on 

 every account, one of the three most valuable seams of our entire coal 

 measures. The only two with which it can be fairly compared in econ- 

 omic importance are the Upper Freeport and the Pittsburgh coals. So 

 far as Ohio is concerned, the seam now to be considered is, in reality, the 

 Upper Kittanning seam ; but in the Pennsylvania scale the present seam 

 is identified as the first seam above the Lower Kittanning coal, while a 

 distinct seam is found in some counties at a somewhat higher place in 

 the scale. It must thus be known, therefore, as the Middle Kittanning 

 coal, though at Kittanning itself, the. locality from which the name is 

 derived, it is the upper of the two seams that are found there. The case 

 is the same in Ohio. 



Of its numerous synonyms no list need be made at this point. By 



