GEOLOGY OF PERU ADAMS. 411 



can have taken place during three hundred and Mtj years as is 

 shown by the position of Indian tumuli. He called attention to how 

 shells may be transported inland by human agencies, by birds, winds, 

 and drifting sands, and advises caution in accepting the mere pres- 

 ence of shells as a proof of elevation. 



Obsekvations in Northern Chile by Alexander Agassiz and L. F. Pourtales. 



In line with the statements by Lieutenant Freyer it may be noted 

 that in northern Chile, in a ravine 20 miles inland from Pisagua at 

 Beringuela (at Tilibiche), at an elevation of 2,900-3,000 feet, " recent 

 corals " were found by Agassiz, who says that they indicate an 

 inland sea connected with the Pacific Ocean, and that there is ac- 

 cordingly reason to believe that the continent has been raised " within 

 a comparative!}^ recent period." 



The corals were described by Pourtales. It is stated that they 

 w^ere fossilized into a compact limestone and consisted of two new 

 species. One was referred to a genus not represented in any lower 

 strata than the Tertiary, and is not now living on the Pacific coast 

 of America. The other species was referred to a genus which had 

 up to that time been described only from Jurassic and Triassic 

 formations. 



The writer wishes to call attention to the fact that the fossils do 

 not date the " comparatively recent period " and do not furnish evi- 

 dence which is more convincing than the relations of the Tertiary 

 sediments, which are widely distributed in the coast region. 



RAPm Reconnaissance of the Tertiary and Quaternary of the 



Coast. 



The writer in traveling through the coast of Peru studying the 

 geology in relation to the underground w^aters, observed the occur- 

 rence and distribution of the Tertiary formations in so far as was 

 possible in the time allotted to his work, and has outlined the occur- 

 rence of the formations in the bvdletins by him published by the Corps 

 of Engineers of Mines of Peru. From what he has written the 

 following summary, which includes a few modifications, is presented 

 with the hope that future observers maj?^ use it to correct and amplify 

 a knowledge of the subject. 



tertiary of the northern coastal plain. 

 The Amotape formation. 



This name was given to the formations which are exposed near 

 the village of Amotape, which is situated in the valley of the Chira 

 River and is particularly well seen in the western end of the Brea 



