Abstract
The western flank of the Haughton impact crater was imaged with a 10.25‐km‐long multifold reflection profile. The seismic waves mapped 10 acoustic discontinuities in the stratified sedimentary target rocks. The impact disturbed the entire 1900 m of the highly competent Paleozoic strata. The average seismic velocity of over 6000 m/s exhibited by these rock units is a clear indication of the undisturbed impact area's unusually high elastic strength. The dynamic and destructive forces of the cratering process are manifested on the seismic profile by a dense and complex system of faults. These steeply dipping faults penetrated the sedimentary rocks but showed no recognizable extension into the crystalline basement. The recognition of normal faults 3 km west of the faulted annulus suggests a structural diameter of 24 km, some 4 km larger than postulated from earlier geological data. It has been found that the surface morphologically distinct ring zones do not have seismically recognizable subsurface signatures. In the central interior region of the crater, coherent reflection signals are lacking. However, some weak local acoustic discontinuities are recognized. The underlying crystalline basement rocks did not exhibit any seismically mappable impact related zones of alteration.
Published Version
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