Scanning electron microscopy (SEM) analysis of microtextures on quartz grains has long been used to assess depositional environment. Recent advances in this field of study indicates that wet-based glaciers produce a unique suite of microtextures on the surface of quartz grains, as a result of extraordinary stress imparted to grains during glacial transport. Glacially induced microtextures are indicated by grooves, gouges and microstriae exhibited on grain surfaces and reflect grain-to-grain contact under high-stress. In contrast, fluvial transport of quartz grains has been found to produce microtextures indicative of grain-to-grain contact as grains bounce along the river bed. These fluvially induced microtextures are indicated by v-shaped cracks and rounding of edges. The goal of this pilot study is to test the survivability of glacially induced microtextures in a fluvial system by progressively sampling modern river sands from glacial front to a distance downstream. This study utilizes the Bear River in British Columbia, Canada as an initial test because the river is easily accessible, emanates from a glacial front, long reach with minimal tributaries and minimal chance of inheritance of inherited microtextures. The results from this pilot study should provide data that demonstrates a progressive overprinting of glacially induced microtextures by fluvially induced microtextures. Yet, the natural variability of rivers is vast and numerous rivers need to be tested to develop meaningful overprinting trends. Thus, this pilot study represents the initial foray of a much larger research project that will attempt to assess progressive, downstream fluvial overprinting of glacially induced microtextures from a variety of proglacial rivers. Successful completion of the larger project will provide proxies for ancient systems that: 1) provide constraints on distance of fluvial transport from glacial front and thus, extent of ancient glacial systems; and 2) estimate paleohydraulic parameters. Thus, the overarching goals of the project will be valuable to a variety of communities, including glacial and fluvial sedimentologists, micromorphologists and geomorphologists. This pilot study provides research opportunities for at least 2 undergraduate students, likely first exposure to a scientific project. These students will be brought on early in the project and involved with field research, laboratory analysis and ultimate showcasing of findings at appropriate scientific venues. Enabling students with scientific research skills early on in the academic path makes better career geoscientists.

Agency
National Science Foundation (NSF)
Institute
Division of Earth Sciences (EAR)
Application #
1324818
Program Officer
Judith Skog
Project Start
Project End
Budget Start
2013-08-01
Budget End
2016-07-31
Support Year
Fiscal Year
2013
Total Cost
$49,943
Indirect Cost
Name
Texas Tech University
Department
Type
DUNS #
City
Lubbock
State
TX
Country
United States
Zip Code
79409