22 Geology of the MusMngum Valley. 



very heavy ; composition similar to that species called "fire clay," 

 and resembles the variety used in the manufacture of stone ware, 

 and in making bricks for furnace hearths ; breaking into irregular, 

 but generally rhombic fragments, with no disposition to a slaty struc- 

 ture, and destitute of any traces of fossil plants. A similar clay is 

 often found resting on the roofs of coal beds. The lower portion, 

 for sixteen or eighteen inches, is of a fine, smooth, argillaceous mate- 

 rial and of a slaty structure, and is filled with impressions of plants, be- 

 tween the contiguous lamina. The leaves and stems are replaced by 

 a yellow ochery matter, in some instances looking like the faded plant 

 on a dark red ground. The figures of plants described above are from 

 this bed. Many more species are found here, similar to those that 

 will be described from another deposit a few miles from this. — 2 feet. 



7. Hard, and fine grained, argillaceous rock ; bluish color; break- 

 ing into irregular fragments ; when fresh broken, imparting a sul- 

 phureous odor. It was probably formed from marsh mud. — 10 feet. 



8. Ash colored, slaty sandstone, in thin layers, containing a large 

 share of mica. Texture loose and friable. — 20 feet. 



9. Dark brown, slaty marl, alternating with thin beds of ash col- 

 ored marl ; the lines of separation, plainly shewing its deposition 

 from water. It is very friable and crumbles on exposure to the air 

 and frosts into a dark red, or brown argillaceous soil, producing fine 

 crops of wheat and small grain. The brown portions of this deposit 

 are filled with impressions of the sphenopterous class of plants, the 

 foliage of which is more coarse, and larger than in the bed described 

 above. It also contains a vast many impressions of the thick leaved 

 plant like NeLumbium luteum. — 10 feet. 



10. Hard slaty sandstone, very fissile, color inclined to brown, 

 splitting into folia of from one eighth of an inch to an inch in thick- 

 ness, contains a large proportion of mica, especially on the surface 

 between the layers. It has the appearance of having been subject- 

 ed to considerable heat. — 10 feet. 



11. Bed of the Ohio river. 



Many of these deposits are very extensive and cover a great many 

 square leagues — apparently dipping towards the Ohio river, both on 

 its right and left banks, so that, this river, although wending its way 

 amidst a wilderness of hills, yet flows in the most depending portion 

 of the valley. The red shale, or brown marl deposits appear, so 

 far as I have observed, to be confined chiefly to within forty or fifty 

 miles of the Ohio, on either side, from the mouth of the Guyandott 

 to the mouth of Walhouding, or Big Beaver river, and probably 



