Mountain Building Processes: Insights from Analog Models
Department
Geosciences and Geological and Petroleum Engineering
Major
Geophysics
Research Advisor
Hogan, John Patrick
Advisor's Department
Geosciences and Geological and Petroleum Engineering
Funding Source
Geo 401 Adv. Structural Geology
Abstract
Strain distribution within the crust during continental collision can be visualized using "sandbox experiments". We investigated the affect of a weak ductile layer and variation in lithostatic load on crustal deformation during compression. The control experiment consisted of dry sand with horizontal marker layers subjected to compression by shortening the sandbox length. Thrust faults and folds developed beneath a thickening sand wedge. Successive experiments included weak ductile layers (all purpose-flour) and varied the lithostatic load to mimic conditions found in the Himalayas. Results suggest that faults in the rigid strata initially are steeper and more numerous than those in the ductile strata. As shortening increases dip angles become similar. Antithetic faulting occurs in experiments where a ductile layering was present. We suggest that mechanical strength properties and thickness of strata (e.g., weak/strong) has a significant impact on the number and dip angle of thrust faults formed during compressional "mountain-building" events.
Biography
Jeff Bender is currently an undergraduate student in Geophysics. His primary emphasis area is exploration geophysics/seismology. Anticipated graduation is May 2010.
Research Category
Sciences
Presentation Type
Poster Presentation
Document Type
Poster
Location
Upper Atrium/Hallway
Presentation Date
08 Apr 2009, 9:00 am - 11:45 am
Mountain Building Processes: Insights from Analog Models
Upper Atrium/Hallway
Strain distribution within the crust during continental collision can be visualized using "sandbox experiments". We investigated the affect of a weak ductile layer and variation in lithostatic load on crustal deformation during compression. The control experiment consisted of dry sand with horizontal marker layers subjected to compression by shortening the sandbox length. Thrust faults and folds developed beneath a thickening sand wedge. Successive experiments included weak ductile layers (all purpose-flour) and varied the lithostatic load to mimic conditions found in the Himalayas. Results suggest that faults in the rigid strata initially are steeper and more numerous than those in the ductile strata. As shortening increases dip angles become similar. Antithetic faulting occurs in experiments where a ductile layering was present. We suggest that mechanical strength properties and thickness of strata (e.g., weak/strong) has a significant impact on the number and dip angle of thrust faults formed during compressional "mountain-building" events.
Comments
Joint project with Melinda Rushing