Fluvial Overprinting of Glacially Induced Microtectures on Quartz Grains Derived from the Chitina Glacier, Alaska
Brannan D. Fluvial Overprinting of Glacially Induced Microtectures on Quartz Grains Derived from the Chitina Glacier, Alaska. Texas Tech University
Microtextures revealed through scanning electron microscopy (SEM) of quartz grain surfaces can be useful for interpreting sedimentary transport mechanisms, especially in eolian, fluvial, and glacial depositional environments. Few studies have applied SEM microtextural analysis with systematic sampling to assess the degree of surface modification when grains experience multiple episodes of transport style. Transport-induced microtextures can be grouped based on the process of fracturing into: (1) sustained high shear stress fractures created through grain-to-grain stylus contact (i.e. troughs, grooves and gouges), (2) percussion fractures created through grain-to-grain impacts during saltation or traction flow, and (3) polygenetic fractures that reflect fracturing under a wide variety of transport processes. This study attempts to ascertain the degree of fluvial modification of glacially derived grains within the Chitina River of SE Alaska. In total, 41 samples were collected in ~5km increments over the entire 188 km length of the river beginning at the Chitina Glacier terminus for a total analysis of 1,000 quartz grains.
- Type
- Academic
- Authors
- Brannan, David
- Publisher
- Texas Tech University
- Units
- CAKN , WRST
- Keywords
- Barnard Glacier, Chitina Glacier, Hawkins Glacier, Kennicott Glacier, thesis
- Subjects
- Ecological Framework: Geology and Soils | Geomorphology | Glacial Features and Processes