STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 65 



near Tappahannock, Virginia, where a bed of massive hard peat is 

 exposed for half a mile. This is covered with plastic clay, i to 4 

 feet, underlying 10 to 15 feet of coarse sand. One sees many 

 cypress stumps in place, with their " knees " projecting into the sand. 

 Where the subsidence was accompanied or followed by disturbance, 

 the evidence appears in the more or less planed or eroded surface 

 on which gravel or sands rest, as is shown in a photograph of peat 

 with embedded cypress stumps, which is unconformable by erosion 

 to the overlying sands. 



Greater interest attaches to the interglacial buried peats, which 

 have been covered with material transported during the Ice Age. 

 These, underlying clays, sands or gravels, exhibit many features 

 which are important here. Such deposits have been observed in 

 many lands. 



The deeply buried peat of Montgomery county, Ohio, originally 

 studied by E. Orton, Sr., has been restudied by Dachnowski.'*^ The 

 exposure is in the bank of a tributary to the ]Miami River and under- 

 lies 80 to 100 feet of stratified clay and gravel. There are indica- 

 tions that the deposit is part of a large area and that it marks the 

 deeper portion of an extensive water-basin. The thickness, as now 

 exposed, is from i to 4 feet, but, 45 years ago when Orton's descrip- 

 tion was written, it was from 12 to 20 feet. The uppermost layers 

 contain undecomposed sphagnum-mosses and underlie fine silty blue 

 clay. The lower portions grade into a well-decomposed, very com- 

 pact peat which holds fragments of wood. This peat rests on several 

 feet of fine sand underlain by clay and gravel. Near the southern 

 margin, according to Orton, a large quantity of timber was found, 

 roots, branches and twigs, much of which had been flattened by 

 pressure. The wood is largely but not exclusively coniferous. New- 

 berry^^ recalled Collett's discovery in much of southern Indiana of 

 a buried deposit, 2 to 20 feet thick, containing rooted stumps. In 

 later years, W J McGee, F. Leverett, F. B. Taylor and J. W. Gold- 

 thwait have described interglacial deposits, some of which are very 

 extensive. 



"s A. Dachnowski, " Peat Deposits of Ohio," Geol. Surv. Ohio, Bull. 16, 

 1912, pp. 102, 103. 



''^J. S. Newberry, "Geological Survey of Ohio," Vol. II., 1874, pp. 30-32. 



