The dispersion of fibrous amphiboles by glacial processes in the area surrounding Libby, Montana, USA

Environmental Earth Sciences
By: , and 

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Abstract

Mining operations began at a world-class vermiculite deposit at Vermiculite Mountain near Libby, Montana, circa 1920 and ended in 1990. Fibrous and asbestiform amphiboles intergrown with vermiculite ore are suspected to be a causative factor in an abnormally high number of cases of respiratory diseases in former mine and mill workers, and in residents of Libby. The question addressed in this report is whether some of the amphibole from Vermiculite Mountain could have been dispersed by Pleistocene glacial processes rather than by human activity after vermiculite mining began. The history of Pinedale glaciation in the Libby area provides a framework for estimating the presence and distribution of asbestiform amphiboles derived from Vermiculite Mountain and found in naturally occurring sediments of Glacial Lake Kootenai that underlie the Libby Valley area. There were two situations where sediments derived from Vermiculite Mountain were deposited into Glacial Lake Kootenai: (1) as lake-bottom sediments derived from meltwater flowing down Rainy Creek when the valley south of Vermiculite Mountain was free of ice but active ice still covered Vermiculite Mountain; and (2) as lake-bottom sediments eroded from the Rainy Creek outwash and re-deposited during a re-advance of the Purcell Trench Glacier lobe near Moyie Springs, Idaho.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The dispersion of fibrous amphiboles by glacial processes in the area surrounding Libby, Montana, USA
Series title Environmental Earth Sciences
DOI 10.1007/s12665-010-0832-8
Volume 64
Issue 1
Year Published 2011
Language English
Publisher Springer
Contributing office(s) Central Mineral and Environmental Resources Science Center
Description 12 p.
First page 157
Last page 168
Country United States
State Montana
City Libby
Other Geospatial Vermiculite Mountain