60 C. H. HITCHOCW K — GEOLOGY OF OAHU 



Near the middle of the section is a bed of oysters, fossilized where 

 they grew and belonging to a species not represented in the recent fauna 

 of the islands or in the kitchen-middens. The beds of which the above 

 section is composed are newer than and situated above the coral-reef 

 rock, which for the purposes of designation may be termed the Pearl 

 Harbor formation. No mollusks or other fossils except the oyster and 

 a few fragments of barnacles were found in this locality. The limy cla} r 

 or marl above the layer with oysters showed unmistakable evidence of 

 wave action in its structure, while the decomposed lava earth above 

 was evidently an alluvial deposit. 



To sum up, it is concluded that" the reef rock of Pearl Harbor and 

 Diamond Plead limestones are of late Tertiary age, which may corre- 

 spond to the Pliocene of west American shores, or even be somewhat 

 earlier, and in the localities studied there was no evidence of any Pleis- 

 tocene elevated reefs whatever. It is probable that Oahu was land, 

 inhabited by animals, as early as the Eocene. 



