166 APPENDIX D. GEOLOGY. 



ured fifteen feet in diameter. At 9 o'clock we came to a small creek, 

 with high banks composed of gray calcareous loam, from which latter 

 I obtained a number of shells, characteristic of the loess formation ; 

 Helix plebeium, Succinea elongata, &c. Soil barren and sandy; subsoil 

 in some places argillaceous, in others arenaceous. 



June 9. — Passed to-day a number of small ravines, the sides of which 

 were composed of red clay, overlaid by sandstone and drift. The surface 

 was in many places covered with sand-hills, varying from ten to fifty 

 feet in height. About 8 o'clock we came to an outcrop of finely lam- 

 inated red ferruginous sandstone, presenting an irregular dip to the 

 northeast of about thirty degrees, (see section No. 4.) Soil arena- 

 ceous ; subsoil in many places argillaceous. 



June 10. — Formation the same as on yesterday. "We frequently 

 found the sandstone exposed and exhibiting evidences of violent disturb- 

 ance, the strata being variously fractured, and in some places upheaved 

 in such a manner as to stand almost perpendicular. With the exception 

 of the creek bottoms, the soil was sandy and barren ; subsoil the same 

 as before. 



June 11. — The surface to-day presented nothing but a succession of 

 hills composed of blown sand, varying in height from ten to one hun- 

 dred feet. No sandstone or drift was anywhere observed. 



June 12. — To-day I observed large quantities of drift, of the same 

 composition as before ; through it were scattered small boulders, com- 

 posed of quartz and mica-schist. The surface was in many places 

 covered with loose fragments of carbonate of lime. The particles com- 

 posing the drift were frequently thickly coated with the same substance. 

 Soil and subsoil arenaceous. 



June 13. — Did not leave camp. 



June 14. — Drift and limestone the same as before. About V o'clock 

 we came to a small ravine, the sides of which exposed a horizontal 

 stratum of coarse-grained sandstone twenty feet thick. From the drift 

 I obtained specimens of agates, chalcedony, and fossil-wood. Soil and 

 subsoil the same as before. 



June 15. — The country travelled over to-day was everywhere divided 

 by ridges and ravines ; the former sometimes sloping gradually on either 

 side — at others presenting abrupt precipitous terminations. Besides 

 these, a large number of sand-hills, varying in height from twenty to 

 one hundred feet, were observed. The sandstone was frequently exposed. 

 In a few places I found it interstratified with course conglomerate ; saw 

 a number of small boulders, composed mostly of greenstone, greenstone 

 porphyry, and trachyte. In the bed of the river I found a large mass 



