U.S. Geological Survey Open-File Report 03-353
Online Only
Version 1.0
2003
1U.S. Geological Survey, 2280 Woodale Drive, Mounds View, MN 55112
2Wisconsin Geological and Natural History Survey, Madison, WI 53711
3U.S. Geological Survey, MS 954, Reston, VA 20192
|
In 1998 the U.S. Geological Survey (USGS) initiated a study to examine the natural regional environmental impact of sulfide mineralization exposed to episodic weathering and glaciation. The study focused on the Bend copper-gold massive sulfide deposit located in the Medford District of the Chequamegon National Forest in north central Wisconsin. The Bend massive sulfide deposit is a small, metal-rich sulfide body hosted by Paleoproterozoic metavolcanics. The mineralized horizon subcrops beneath 100-120 feet of glacial cover, and consists of massive pyrite and other sulfides. Bedrock and ore geochemistry are well characterized by analyses of diamond drill core provided to the USGS by Sharpe Energy and Resources. In July 1999, five rotasonic drillholes were completed through the unconsolidated Quaternary sediment, averaging about 100 feet thick, on a transect across the Bend deposit. Nearly continuous core was recovered from the surficial material along with several feet of the underlying bedrock. Samples representing the entire section were analyzed by the USGS to give a two-dimensional representation of element dispersal from the unmineralized bedrock. In addition, one hundred regional till samples were subsampled from the archives of the Quaternary Sediment Laboratory in the University of Wisconsin-Madison Department of Geology and Geophysics. These regional samples were collected mainly from Taylor County, where the Bend deposit is located, as well as contiguous parts of Clark and Marathon Counties. This open file report presents all of the geochemical data collected for this study. Additional publications describing the data in more detail are being completed. |
 |
Map showing the location of study area and the bedrock and glacial geology of Northern Wisconsin. |
 |
Map showing the location of rotasonic boreholes and trace of mineralization at the Bend massive sulfide deposit. |
|
FILES
|
DESCRIPTION
|
|
Word document format of open file report.
|
|
|
Portable Document Format (PDF) of open file report.
|
|
FILES
|
DESCRIPTION
|
|
Analyses of rock samples taken from diamond drill core.
|
|
|
Analyses of mineralized and altered rock associated with massive sulfide mineralization at the Bend deposit.
|
|
|
Analyses of massive sulfide from the Bend deposit.
|
|
|
Analyses of till samples collected in the region around the Bend massive sulfide deposit, including samples from Taylor, Marathon and Clark counties.
|
|
|
Analyses of unconsolidated glacial material and regolith collected from five rotasonic boreholes drilled in the immediate vicinity of the Bend massive sulfide deposit.
|
|
FILES
|
DESCRIPTION
|
|
Adobe Illustrator (ai) map showing the location of study area and bedrock and glacial geology of Northern Wisconsin.
|
|
|
Portable Document Format (PDF) map showing the location of study area and bedrock and glacial geology of Northern Wisconsin.
|
|
|
Adobe Illustrator (ai) map showing the location of rotasonic boreholes and trace of mineralization at the Bend massive sulfide deposit.
|
|
|
Portable Document Format (PDF) map showing the location of rotasonic boreholes and trace of mineralization at the Bend massive sulfide deposit.
|
|
Adobe Reader is required to view Portable Document Files (PDF).
|
For questions, please contact Laurel G. Woodruff or William F. Cannon.
[an error occurred while processing this directive]