Deep Cores of Oahu, Hawaii and Their Bearing on the Geologic History of the Central Pacific Basin

Abstract

In the Central Pacific Basin few studies of the earth's crust have been made, and those studies that have been undertaken have been mainly geophysical in nature: seismic, magnetic, heat flow, and gravity surveys. These geophysical data usually require for their correct interpretation some knowledge of the geologic properties of the crust, especially the upper crust; consequently, in order to supplement these geophysical data and for other more direct reasons, e.g., stratigraphic, palaeontologic, petrologic, etc., there has been for a long time a desire to take actual samples of the Central Pacific Basin crust. To realize this goal H.S. Ladd, J.I. Tracey, K.O. Emery, and others in the last twenty years have drilled several deep holes on Central Pacific islands. Unfortunately, the drilling techniques used did not allow the recovery of a core sample, so that actual lithologic sections of the upper crust were not obtained.