EVIDENCE OF STREAM MIGRATION AND PIRACY NEAR TUPELO, MISSISSIPPI (Invited Presentation)

Surface geologic mapping along the Natchez Trace Parkway and National Scenic Trail resulted in identification of evidence of stream migration and stream piracy in the Tupelo 7.5 minute quadrangle. The mapping was conducted as part of the National Park Service’s delineation of geologic resources.

Surficial units mapped on the Tupelo quadrangle were Cretaceous sediments with Quaternary alluvium and terrace deposits. There were different levels of terrace deposits identified. The location and orientation of some of those terrace deposits provide evidence of migration of several creeks within the quadrangle. Streams with notable terrace deposits are those of King, Mud, Sand, Town, Tulip, and Yonaba Creeks. Three levels of terrace deposits were mapped of King and Yonaba Creeks, both indicating that those streams courses have migrated toward the southwest.

Stream terrace deposit mapping also provided evidence of stream piracy. The mapped terrace deposits provide evidence that Brock Creek has been captured by Sand Creek with Little Sand Creek now occupying the lower portion of the original course of Brock Creek. Mapped terrace deposits also provide evidence that Mud Creek had been captured by a stream to the east from where its terrace deposits were located.

Mapping of the stream terrace deposits and differentiating between the different levels of terraces allowed for the determination of stream migration and the direction of migration as well as streams that had been pirated. Had the different levels of terraces not been determined, migration would have been more difficult to determine and therefore stream piracy may have not been determined.