Analysis of drainage-basin symmetry as a rapid technique to identify areas of possible Quaternary tilt-block tectonics: an example from the Mississippi Embayment


There is a coincidence of seismicity and major river valleys in the southwestern Mississippi Embayment that suggests control of the drainage patterns by northwest-trending faults. Pleistocene river terraces reveal a strong southwestward preferred river migration in this region that may be result of fault-block tilting. A rapid new technique of drainage-basin analysis is herein presented that quantifies transverse topographic basin symmetry. These data permit discrimination of random stream migrations and regionally preferred stream migrations and identify the direction of maximum migration. Although this technique does not provide direct evidence of ground tilting, it provides a quick-look method of identifying possible tilting elements in neotectonic regions using only topographic maps. This technique is of greatest utility where active faults are concealed or poorly exposed, such as in the Mississippi Embayment. -from Author

Publication Title

Geological Society of America Bulletin