414 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1908. 



a sketch (fig. ^ of the relation of these two 

 formations, and upon sailing southward made 

 a similar sketch (fig. 6) showing the relations 

 of the bed as seen after rounding the point. 

 The presence of the bubonic plague at Paita 

 during the writer's visit, and especially the 

 establishing of the hospital to the west of the 

 town, prevented a thorough examination of the 

 locality. Grzybowski, in his article, mentions 

 some shales cut by minute quartz veins which 

 he found outcropping to the west of Paita near 

 Paita Point. These shales, which were not well 

 seen by the writer, were included by him in 

 his sketch as a part of the Amotape formation. 

 The division between the Amotape and upper 

 formation shown in the sketch corresponds ap- 

 proximately with the dividing line betw^een the 

 shales and sandstones of Grzybowski's section 

 at Paita ° (fig. 7). Grzybowski has described 

 what he calls the " Paita stage " from the 

 locality at Paita, and if it had not been for 

 this the writer would apply the name Paita 

 formation to the upper one, which he has 

 differentiated. 



The age of the beds at Paita was not well 

 determined by the fossils which Gabb received. 

 He states that some of the fossils were extinct 

 forms, and that the remainder appeared to be 

 Pliocene. Grzybowski assigned the Pliocene 

 age to his Paita stage. The writer thinks that 

 the unconformity which he has shown in his 

 section is unmistakable, and that accordingly 

 he would call the upper beds Pliocene. The 

 extent of this formation has not been deter- 

 mined with certainty, but it apparently occu- 

 pies the upper portion of the table-land of 

 Paita. To the north, in the plains around la 

 Brea hills, it is not to be found in extensive 

 areas, since the good exposures which were 

 seen all belong to the Amotape formation. 

 The Brea hills w^ere perhaps above the level 

 of the sea during the time it was deposited. 

 It may be more appropriately expected south- 

 ward, underlying the desert of Sechura. 



^ Original figure in Neues Jalirbucli fiir Mineralogie, Beilagcbaud XII, PI. 

 XVI, fig. 1. 



