Integrated Potential-Field and Seismic Reflection Studies of the Midcontinent Rift in Eastern Lake Superior

Abstract

Potential-field studies have historically played a major role in delineating the 2000 km extent of the Midcontinent Rift (MCR) that occurs beneath the overlying Phanerozoic strata of the craton. Recently, the acquisition of high resolution aeromagnetic data in addition to deep crustal seismic reflection surveys has provided investigators the opportunity to perform integrated geophysical studies that result in more quantitative, less ambiguous interpretations. Magnetic modeling algorithms have been developed to take advantage of the magnetic data in an attempt to gain a more detailed perspective of the structural and stratigraphic aspects of the Keweenawan volcanic rocks associated with the MCR in eastern lake Superior. In addition, gravity data modeled in conjunction with seismic reflection and refraction constraints provide further information on the distribution of rift-filling sedimentary rocks as well as rift-related lower crustal modification.