woodworth: geological expedition to brazil and chile. 127^ 



able to detect anything like Pleistocene beaches or the work of waves 

 at elevations above that of the plain of Concepcion and this plain is 

 practically the only evidence of a former stand of the land lower than 

 the present sea-level since the time of the Tertiary and older deposits 

 which contain marine fossils. 



Darwin was familiar with the fact that the natives carry large 

 quantities of shell-fish inland, but in commenting on the fragments of 

 shell-bearing forms such as sea-urchins found several miles inland from 

 the coast he doubted the human origin of many deposits on the ground 

 that it was improbable that the natives would transport such materials 

 to any distance from the coast. On the contrary, it is well known that 

 sea-urchins are an article of food in Chile. I saw in the market at 

 Tamuca baskets of a large sea-urchin with the spines attached. The 

 natives use for food many shell-fish which the unnaturalized European 

 does not think of utilizing and if one objects that in the Pre-Columbian 

 days such stores of food would decay in the course of a distant inland 

 journey due allowance must be made for savage tastes. The "hung" 

 meats and festering cheeses of civilized countries show how much 

 latitude must be allowed for aberrant tastes. In the semi-arid and 

 arid climatic zones of the Coastal Cordillera many Mollusca would 

 become dessicated rather than putrid because of a belated consump- 

 tion. In fact the unusual distance to Avhich shell accumulations are 

 found back from the coast of Chile appears to me quite compatible 

 with the physical environment of an aboriginal people whose hinter- 

 land in the Longitudinal Valley was in primitive times less fruitful 

 than the adjoining sea. Kitchen-middens occur here in every degree 

 of accumulation from the now sparsely scattered shells in the sod 

 marking a temporary abode to the thick shell-heap on the site of 

 permanent habitations. Shells on the surface or buried in the super- 

 ficial subaerial deposits along this coast are no more a criterion of 

 submergence beneath the sea than elsewhere and cannot be relied 

 upon as proving anything other than the agency of man. 



The Red Soil. — Along the Avestern slopes of the Coastal Cordillera 

 there are large tracts with a red soil, the characteristic effect of the 

 subaerial decomposition of rocks. The situation of these residual 

 deposits, the nature of the topography without beaches or marks of 

 wave action, and the abundant traces of the secular leaching by rains 

 and moisture, together with the gullying of the> ancient surface on 

 which these deposits occur, alike bespeak ordinary atmospheric 

 processes as conditioning the formation of this red earth. The 

 occurrence of shells and other exuviae in this deposit is but an indica- 



