Model for the tectonic evolution of the Mississippi embayment and its contemporary seismicity

Abstract

Research Article| December 01, 1981 Model for the tectonic evolution of the Mississippi embayment and its contemporary seismicity M. F. Kane; M. F. Kane 1U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar T. G. Hildenbrand; T. G. Hildenbrand 1U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar J. D. Hendricks J. D. Hendricks 1U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Geology (1981) 9 (12): 563–568. https://doi.org/10.1130/0091-7613(1981)9<563:MFTTEO>2.0.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation M. F. Kane, T. G. Hildenbrand, J. D. Hendricks; Model for the tectonic evolution of the Mississippi embayment and its contemporary seismicity. Geology 1981;; 9 (12): 563–568. doi: https://doi.org/10.1130/0091-7613(1981)9<563:MFTTEO>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Aeromagnetic and gravity surveys of the northern Mississippi embayment have delineated a northeast-trending basement depression about 70 km wide and more than 300 km long. The feature, the Mississippi Valley graben, is remarkably linear over its known length, has nearly parallel sides, and has estimated depths relative to surrounding basement of more than 2 km. Both gravity and magnetic anomalies show an alignment of dense magnetic plutons along the boundaries of the graben. Estimated magnetization directions for the plutons indicate a Mesozoic age. The graben, of probable earliest Paleozoic age, underlies the northwest side of the embayment and contains the area of major seismicity. In particular, much of the instrumentally located contemporary seismicity and the estimated locations of the large-magnitude 1811–1812 earthquakes are in the central part of the graben. We interpret the early Paleozoic graben, the Mesozoic plutonism, and the sedimentation cycles as evidence of stretching events. Seismicity is attributed to strain in and below the central graben area, which would appear to be a focal point of deformation in the stretching model. We suggest that the sequence of events can be explained by the action of a rotating horizontal stress field on a crustal flaw that persisted well back in Pre-cambrian time. The postulated rotating stress field is presumably controlled by the system that drives the global plates. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.