Loess origin, transport, and deposition over the past 10,000 years, Wrangell-St. Elias National Park, Alaska

Aeolian Research
By: , and 

Links

Abstract

Contemporary glaciogenic dust has not received much attention, because most research has been on glaciogenic dust of the last glacial period or non-glaciogenic dust of the present interglacial period. Nevertheless, dust from modern glaciogenic sources may be important for Fe inputs to primary producers in the ocean. Adjacent to the subarctic Pacific Ocean, we studied a loess section near Chitina, Alaska along the Copper River in Wrangell-St. Elias National Park, where dust has been accumulating over the past ∼10,000 years. Mass accumulation rates for the fine-grained (<20 μm) fraction of this loess section are among the highest reported for the Holocene of high-latitude regions of the Northern Hemisphere. Based on mineralogy and geochemistry, loess at Chitina is derived from glacial sources in the Wrangell Mountains, the Chugach Mountains, and probably the Alaska Range. Concentrations of Fe in the silt-plus-clay fraction of the loess at Chitina are much higher than in all other loess bodies in North America and higher than most loess bodies on other continents. The very fine-grained (<2 μm) portion of this sediment, capable of long-range transport, is dominated by Fe-rich chlorite, which can yield Fe readily to primary producers in the ocean. Examination of satellite imagery shows that dust from the Copper River is transported by wind on a regular basis to the North Pacific Ocean. This Alaskan example shows that high-latitude glaciogenic dust needs to be considered as a significant Fe source to primary producers in the open ocean.

Study Area

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Loess origin, transport, and deposition over the past 10,000 years, Wrangell-St. Elias National Park, Alaska
Series title Aeolian Research
DOI 10.1016/j.aeolia.2013.06.001
Volume 11
Year Published 2013
Language English
Publisher Elsevier
Contributing office(s) Geosciences and Environmental Change Science Center
Description 15 p.
First page 85
Last page 99
Country United States
State Alaska
Other Geospatial Wrangell-St. Elias National Park
Google Analytic Metrics Metrics page
Additional metadata about this publication, not found in other parts of the page is in this table