Characterization of Magnetic & Micromorphologic Signatures in Seismically Disturbed Sediment & Sedimentary Rocks
Mentor 1
John Isbell
Location
Union Wisconsin Room
Start Date
28-4-2017 1:30 PM
End Date
28-4-2017 4:00 PM
Description
Deformation and deposition of sedimentary materials resulting from earthquakes remain poorly understood despite their importance in identifying areas and times of intense tectonically activity in and adjacent to sedimentary basins. These strata are occasionally misidentified as glacial or the result of rapid deposition. Therefore, their identification is essential in making accurate determinations of seismic events. Direct objectives of this study are to continue determining magnetic characteristics and microscopic deformation features resulting from earthquake induced liquefaction of sedimentary deposits, furthering our understanding of when and where seismic activity occurred in deep time. A suite of sedimentary rocks and paleomagnetic cores were collected from Mississippian age strata exposed near Garrison, Kentucky. These strata were previously interpreted to be a result of earthquakes. The strata were logged for vertical and lateral changes in sedimentary structures, facies, and textures. Samples were processed by hand into petrographic thin sections for micromorphological analysis to determine deformation processes during liquefaction, and spatially oriented rock cores were processed for magnetic susceptibility and examined to determine their magnetic fabrics. Small-scale simulation experiments recreating similar earthquake deformation were run and the resultant deposits were examined for similarities and differences with features observed in the rock samples. Further analysis is required to fully understand the seismic events these sediments have undergone.
Characterization of Magnetic & Micromorphologic Signatures in Seismically Disturbed Sediment & Sedimentary Rocks
Union Wisconsin Room
Deformation and deposition of sedimentary materials resulting from earthquakes remain poorly understood despite their importance in identifying areas and times of intense tectonically activity in and adjacent to sedimentary basins. These strata are occasionally misidentified as glacial or the result of rapid deposition. Therefore, their identification is essential in making accurate determinations of seismic events. Direct objectives of this study are to continue determining magnetic characteristics and microscopic deformation features resulting from earthquake induced liquefaction of sedimentary deposits, furthering our understanding of when and where seismic activity occurred in deep time. A suite of sedimentary rocks and paleomagnetic cores were collected from Mississippian age strata exposed near Garrison, Kentucky. These strata were previously interpreted to be a result of earthquakes. The strata were logged for vertical and lateral changes in sedimentary structures, facies, and textures. Samples were processed by hand into petrographic thin sections for micromorphological analysis to determine deformation processes during liquefaction, and spatially oriented rock cores were processed for magnetic susceptibility and examined to determine their magnetic fabrics. Small-scale simulation experiments recreating similar earthquake deformation were run and the resultant deposits were examined for similarities and differences with features observed in the rock samples. Further analysis is required to fully understand the seismic events these sediments have undergone.
