Title

Mountain Building Processes: Insights from Analog Models

Presenter Information

Jeffrey Bender

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

Comments

Joint project with Melinda Rushing

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Apr 8th, 9:00 AM Apr 8th, 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.