Character and distribution of borehole breakouts and their relationship to in situ stresses in deep Columbia River Basalts ( Washington State, USA).

The character and distribution of borehole breakouts in deeply buried basalts at the Hanford Site in S central Washington State are examined in light of stress indicator data and hydraulic- fracturing stress data by means of acoustic televiewer and acoustic waveform logging systems. A series of boreholes penetrating the Grande Ronde Basalt of the Columbia River Basalt Group were logged to examine the extent of breakouts at depths near 1000 m. -from Authors