Paleomagnetism of the Grande Ronde (Lower Yakima) Basalt Exposed at Sentinel Gap:Potential Use for Stratigraphic Correlation

摘要

Directions of natural remanent magnetization were measured in each of the twelve superposed Grande Ronde (lower Yakima) Basalt flows exposed at Sentinel Gap, Washington. The sequence of changes in the natural remanent magnetism direction in these flows is sufficiently distinct that identification and correlation at other surface - and subsurface -sampling sites should be possible. Preliminary tests made on the feasibility of measuring variations in the ancient field intensity in these flows indicate they are not suitable for intensity measurements.