Koolau Dike Complex, Oahu: Intensity and origin of a sheeted-dike complex high in a Hawaiian volcanic edifice

摘要: The dike complex in the eroded Koolau tholeiitic shield volcano is unique among: described swarms for its coherence, high dike-injection intensity, relatively uniform and non-Gaussian 50% to 65% intensity level, lack of divergence. Parts are like a sheeted-dike complex, though an intraplate volcanic edifice. A model proposed which highly mobile magma, having considerable freedom move through strongly disjointed volcano, seeks zones it gravitationally most stable. These marginal parts separating lavas lower-than-magmatic bulk density from >50% higher-than-magmatic density. This also explains strong propensity magma Kilauea remain underground (in stable zone). Magma erupts only when vesiculates sufficiently; often, has degassed, some promptly plunges back toward zone again.