310 Bowman — Geologic Relations of the Guzco Remains. 



We must now consider the possibility of landslip. A block 

 of gravel ma} 7 slide by slow degrees from the top of a bluff 

 and come to rest at the foot with stratification intact and with 

 a dip in conformity with that of the beds in the undisturbed 

 parent mass. In such a case it is evident that (1) between the 

 disturbed and the undisturbed masses a break will occur and 

 (2) both the material and the thickness and alternation of the 

 beds will show marked contrasts on the two sides of the break. 

 Now the bluff in which the Cuzco man was found is to some 

 extent ravined and broken by landslips. East of the locality a 

 series of small slips extend down valley for several hundred feet 

 with characteristics quite unlike the undisturbed condition of 

 the lense containing the bones. The line of separation between 

 them and the parent mass is everywhere ragged with both 

 horizontal and vertical variations. Material has been dragged 

 down from an upper surface and is exposed to view near the 

 bottom of the ravine. Such material exhibits recent unfos- 

 silized shells, even human bones and pieces of broken pottery, 

 carbonized wood and corn, and the ashes of old and long-aban- 

 doned hearths or camp fires. 



No one who sees these clear evidences of the displacement 

 of material by landslips can fail to see the necessity for giving 

 the mass containing the human remains the most rigid exami- 

 nation. At first sight the immediate surroundings indeed sug- 

 gest a landslip. Immediately above the stratum containing 

 the bones was a break in the face of the bluff about four feet 

 long (fig. 5). It rose in a curved line about two feet above the 

 layer in which the bones were disposed and suggested the 

 upper part of a grave, especially as the break exhibited a mould 

 of organic material. After the excavation work was done, as 

 much care was exercised in the examination of this break as in 

 the gathering of the bones. Upon excavation of the gravel 

 along the line of the break and forward from it two facts were 

 discovered : (1) the break extended downward but a few inches 

 and merged into hard undisturbed material in which the bed- 

 ding planes ran apparently without interruption from within 

 the main gravel mass to the outer edge of the bluff ; (2) the 

 mould consisted principally of a fungous growth mixed with 

 a few species of lichens. 



At first the mould-covered material seemed quite out of 

 harmony with the undisturbed structure of the gravel beneath 

 it, but when a larger area of bluff face had been examined a 

 clear explanation was afforded quite apart from the idea of a 

 grave. Anywhere along the faces of these gravel bluffs one 

 may find the same material disposed in the same way. The 

 break afforded an opportunity for the display of the mould but 

 was in no way related to it. Upon the outermost surface of 



