1893.] NATURAL SCIENCES OF PHILADELPHIA. 339 



arroyo type of the arid regions. I am puzzled to know the reasons 

 for these peculiarities. 



(c) JEolian Deposits in the Pecos Valley. — At the western base of 

 the Staked Plains, along the escarpment of the Pecos Valley there 

 is an extensive ieolian deposit about fifteen miles in width. Profes- 

 sor Hill 29 states that this strip of sand is fully one hundred miles in 

 length, extending up into Eddy County, New Mexico. It is plainly 

 due to the prevailing west winds (as suggested by Hill) which have 

 heaped the sands here at the base of the escarpment. It is the most 

 absolute desert waste I ever chanced to see. Crater-like pits and 

 cones of the sand dune type are here most perfectly developed, and 

 the sparse sand-plant growth serves only partially to keep the sand 

 in place. 



It was my ill-fortune to be obliged to study this deposit quite 

 carefully, for my team was unable to carry the loaded wagon over 

 the sandy trail into which the wheels sunk, often to the hub. The 

 difficulties of the trip were increased manifold by the sharp grades 

 caused by the pits and cones, and by the shifting sands. Abandoned 

 wagons proved that I was not the first to find the difficulties of the 

 sandy strip. Being informed of the existence of a ranch a dozen or 

 fifteen miles to the north I started on horseback in search of aid. 

 Mile after mile I travelled in the hot sun with the drifting sand 

 blowing in my face. Everywhere the same scene was before my 

 eyes, the escarpment to the east being my only topographic guide. 

 At last I turned back unsuccessful in my search. My tent was 

 banked up with sand, sand was on everything and in everything. 

 At night the eddies of wind would start whirls of sand within the 

 tent, and cooking was quite out of the question. With four horses 

 I was barely able to get my wagon, not a very heavy one, across this 

 strip of sand. 



So far as I know this deposit is unique in this country in point of 

 size. Blown as it is quite constantly at the face of the escarp- 

 ment it must be a powerful agent of erosion, and it is not impossi- 

 ble that this escarpment owes its present position in large measure 

 to seolian action. The Pecos River is twenty-five or thirty miles 

 away and though this was undoubtedly the originator of the escarp- 

 ment, its present position is due to recession, and, I believe, recession 

 brought about in part by the continual blowing of sand at its base. 



29 1 Hll, Am. Geol., Vol. VII, 1891, p. 3G9. 



