THE REELFOOT RIFT - PAST, PRESENT, AND FUTURE

The Reelfoot rift extends from southern Arkansas into southwestern Kentucky and is the southern portion of the Reelfoot rift-Rough Creek graben-Rome trough fault system that experienced faulting during three periods between 760 Ma and 530 Ma as the southeastern portion of the United States attempted to rip from North America. The NE-trending Reelfoot rift cut across pre-existing NW-trending faults, which resulted in the formation of sub-basins within the rift that may have affected late Proterozoic and Cambrian deposition. Most, if not all, of these faults have been reactivated through time. End of Paleozoic Appalachian-Ouachita compression resulted in the uplift of the Axial fault system down the middle of the Reelfoot rift and the entire rift was part of a larger late Cretaceous thermal uplift caused by the passage of the United States over the Bermuda hotspot. Erosion of the uplift and subsequent thermal subsidence upon passing of the Reelfoot rift region off the hotspot resulted in the formation of the Mississippi embayment. Cenozoic compression has reactivated Reelfoot rift faults that continues into the Holocene. The great New Madrid earthquakes of 1811-1812 occurred on a small portion of the Reelfoot rift and this fault reactivation appears to be related to major Pleistocene erosion within the Mississippi River valley above three Reelfoot rift faults. The question remains as to the possible repeat of these great earthquakes and or the possibility of renewed activity on the remaining Reelfoot rift faults.