26 PP. KEPORT OF PEOGRESS. FONTAIlSrE & WHITE. 



often mottled with green, buff, or yellow spots, and streaks. 

 Towards tlie south, the red and variegated shales increase 

 in thickness, and descend lower in the series, sometimes 

 even nearly to the horizon of the Waynesburg Coal. The 

 red shales are quite conspicuous in Marshall Co., and in 

 the 600 feet of strata shown at Bellton we find about 400 

 feet of red shales, not in a single bed, but in several beds, 

 from 40 to 60 feet thick, alternating with brown sandstones 

 or drab-colored shales. 



The Waynesburg Sandstone, the rock which forms the 

 base of the series, is an imj)ortant stratum, since its phys- 

 ical character denotes plainly a great change in the condi- 

 tions which had prevailed for a long period previous to the 

 time of its formation. As has been previously stated, these 

 conditions were quiet subsidence, and deposition of fine 

 shales, with much limestone. But in the sandstone now de- 

 scribed, we find many evidences of strong currents, which 

 tore up the previously formed coal, and brought in a vast 

 amount of coarse material. The approach of this unquiet 

 condition of things is indicated in the structure of the 

 Waynesburg Coal itself. 



The Waynesburg Coal bed usually contains a parting of 

 blue shale, near the middle, which shows extraordinary 

 fluctuations in thickness. It sometimes disappears entire- 

 ly, but rarely falls below 4 inches in thickness. The most 

 common mode of occurrence is with fluctuations from a 

 few inches up to several feet. It is not uncommon to find 

 in a few yards distance, a sudden thickening from 5 or 6 

 inches up to six feet, and even more. The peculiarity of 

 this shale is made more striking by the fact, that it pos- 

 sesses this character over an area of many thousand square 

 miles ; and while the changes are thus sudden the material 

 is always of fine texture. It is to be observed that the 

 plants yielded by this coal bed are found in the roof-shales, 

 some distance above this variable parting. 



The Waynesburg Sandstone, well characterized, forms a 

 marked feature in the geology of the district where it oc- 

 curs. Its usual thickness is from 50 to 75 feet, and its ordi- 

 nary character that of a coarse conglomeratic rock, in which 



