This paper continues the discussion of the seismicity of the Middle Mississippi Basin. Seismographic and macroseismic data are presented on three Missouri earthquakes: (1) the Little Saline Creek earthquake, January 15, 1945; (2) the Doniphan, Missouri, earthquake, May 15, 1946; and (3) the Little Black River earthquake, December 1, 1947.
Many geological studies have established the existence of three major fault zones in the basement; the Mississippi embayment zone, the Shawneetown-Rough Creek zone, and the Ste. Genevieve zone.
The earthquake of January 15, 1945, is additional evidence that the Ste. Genevieve fault zone is seismically active. The other two shocks are not directly associated with the major fault zones. They, together with previous similar minor activity, may be associated with a deep-seated fault system near the physiographic margin of the Ozarks or with deep-seated fractures on the southeastern flank of the uplift.