Title

The Geologic Progression of the Eastern Snake River Plain

Presentation Type

Poster

Abstract

The Snake River Plain is a complex mega geological structure in the western United States. The Plain is considered to be the result of rifting processes, the lowering of the extinct Yellowstone caldera due to heat loss and gravity effect, or a combination of both processes. Our purpose is to determine which of the process is most strongly supported by previously published studies and first hand observation. Our review of literature focused on two primary methods that have been used to investigate the area. First, we looked into the GPS geodesy method, which tracts the geologic plates movement. GPS velocity measurements indicate that the rate at which the size and shape of the Eastern Snake River Plain is changing is much lower than the adjoining Centennial Tectonic Belt and Great Basin areas. These contrasts in movement indicate rifting and as a result rift basin development. Second, we examined studies performed using mineral analysis of geologic formations in the area. Testing of detrital zircons can indicate the presence of water at the time of their formation. Studies conducted along the Plain show that during the Neogene age (from 23 million to 2.5 million years ago) water drainages flowed away from the current position of the East Snake River Plain to the north and east. The drainages then reversed their flow to the west following the Snake River system to the Pacific coast. Thus, the theory of a Yellowstone Hotspot uplift and its corresponding subsidence, along the path of the Plain is supported as well. Field observations provided evidence of both hotspot activity and lowering due to rifting processes. By super-imposing research methods with field observations, our conclusion is that the East Snake River Plain is a rift basin formation altered significantly by hotspot activity.

Category

Physical Sciences

This document is currently not available here.

Share

COinS
 
Apr 17th, 11:00 AM Apr 17th, 12:00 PM

The Geologic Progression of the Eastern Snake River Plain

South UC Ballroom

The Snake River Plain is a complex mega geological structure in the western United States. The Plain is considered to be the result of rifting processes, the lowering of the extinct Yellowstone caldera due to heat loss and gravity effect, or a combination of both processes. Our purpose is to determine which of the process is most strongly supported by previously published studies and first hand observation. Our review of literature focused on two primary methods that have been used to investigate the area. First, we looked into the GPS geodesy method, which tracts the geologic plates movement. GPS velocity measurements indicate that the rate at which the size and shape of the Eastern Snake River Plain is changing is much lower than the adjoining Centennial Tectonic Belt and Great Basin areas. These contrasts in movement indicate rifting and as a result rift basin development. Second, we examined studies performed using mineral analysis of geologic formations in the area. Testing of detrital zircons can indicate the presence of water at the time of their formation. Studies conducted along the Plain show that during the Neogene age (from 23 million to 2.5 million years ago) water drainages flowed away from the current position of the East Snake River Plain to the north and east. The drainages then reversed their flow to the west following the Snake River system to the Pacific coast. Thus, the theory of a Yellowstone Hotspot uplift and its corresponding subsidence, along the path of the Plain is supported as well. Field observations provided evidence of both hotspot activity and lowering due to rifting processes. By super-imposing research methods with field observations, our conclusion is that the East Snake River Plain is a rift basin formation altered significantly by hotspot activity.