11/23/2009
METAL MINING AND MERCURY
W. Charles Kerfoot & Noel Urban (Michigan Tech University), Ron Rossmann (EPA-Grosse Isle), John Robbins (NOAA-GLERL)
Lab Setting-Water View
1 11/23/2009
Funding Sources
¾ NOAA/NSF KITES Project (NSF OCE) ¾ U.S. EPA Region V Grant to Baraga Tribal Council ¾ Michigan Department of Environmental Quality (MDEQ) ¾ U.S . ACE Vicksburg ERDC-EL (LiDAR CHARTS)
Changing Beliefs
¾ Mining is a serious source of atmospheric mercury discharge in the world & U.S. (historic legacy, current practice) ¾ The mineral cinnabar (HgS) is present in the Lake Superior watershed ¾ Mercury is associated with metal mining (Copper, Iron) in the Upper Peninsula
2 11/23/2009
Solid Solution Substitution Of Hg For Zn In Sphalerite (Schwartz 1997)
Exhalative deposits SEDEX VOLCEX
3 11/23/2009
Sources For Atmospheric Hg Discharges (2000 Environment Canada vs 1997 U.S. EPA Report To Congress)
On Site Mercury Releases (atmospheric):
2001 EPA Region #9
4 11/23/2009
Mercury In Gold Ore Samples: Geographic Comparisons
Mercury In Lake Sediment (Can. Geol. Survey)
5 11/23/2009
Lake Superior Watershed: Precious And Base Metal Mining
Lake Superior Watershed: Cinnabar And Mercurian Sphalerite
¾ Hemlo Gold Deposit near Marathon:Williams, Golden Giant, David Bell Mines (Michibayashi 1995; Powell and Pattison 1997; Tomkins et al. 2004): Hg 6% in ore samples, 6.7% in concentrates ¾ Massive Sulfide Deposits (12 locations), includes Flambeau Mine, Ladysmith, Ws (Motti et al. 1999): 0.11% Hg in Cu, 1.13% in Ag
6 11/23/2009
Lake Superior Basin-Estimated Atmospheric Mercury Releases (kg/yr)
7 11/23/2009
Quincy Shafthouse
¾ Keweenaw National Park (Native Copper Mining) ¾ 140 Mines, 40 Stamp Mills ¾ 5 Smelters ¾ Torch Lake Superfund Site
8 11/23/2009
Keweenaw Peninsula: Smelter, Mine, Mill Sites
Stamp Mills
Keweenaw Peninsula Coring Sites
9 11/23/2009
Copper/mercury profiles (NSF/NOAA KITES Project) From Deep Water (LSDH) to L’Anse Bay
10 11/23/2009
Anthropogenic Copper Inventories: Spatial Pattern
Anthropogenic Mercury Inventories: Spatial Pattern
11 11/23/2009
Mercury Concentrations In Ore Samples
¾ A) Keweenaw native copper and silver ores
¾ B) World (Cu, Au, Ag) ores and Sphalerite (ZnS)
¾ C) Solid solution substitution (native metal-natural amalgamation) or for Zn in Sphalerite
12 11/23/2009
Torch Lake Superfund Project
13 11/23/2009
Radioisotope Profiles: Keweenaw Waterway (Portage Lake)
¾ A) 137Cs dating
¾ B) 210Pb dating
¾ C) Varves (X-ray bdbands, Cu-rih)ich)- Insert
Copper And Mercury Flux Profiles: Keweenaw Waterway (CG: Near Dollar Bay Smelter)
14 11/23/2009
Portage Lake Sediment Profile
Torch Lake 210Pb Model
¾ Unsupported 210Pb profile (20m site) ¾ CIC-CRS model ¾ Modified CRS model
15 11/23/2009
Torch Lake Sediment Profile
Stamp Sands Discharged By Stamp Mills Along Keweenaw Coastline
16 11/23/2009
Historical Erosion Of Tailings Cone
¾ 1938 air photo of the original stamp sand discharge pile (white) superimposed upon a 1999 air photo (red line, natural shoreline; inner pink line, 1999 shoreline of pile and reworked sands ; outer pink, estimated underwater 1999 dispersal of eroded stamp sands)
Gay Stamp Sand Site
¾ The above-water and underwater extent of the Gay Stamp Sand tailings in Grand Traverse Bay, MI. Note the natural white sand beach to the south of the Traverse River (diagram after Army Corps 2001)
17 11/23/2009
Stamp Sands Threaten Buffalo Reef
¾ Bathymetry and substrate characterization around Buffalo Reef off Gay coastline, Keweenaw Bay. Studies conducted jointly by NWRI (National Research Institute Environment Canada) and GLIFWC (Great Lakes Indian Fish & Wildlife Commission).
US Army Corps of Engineers (Detroit) Remediation
¾ Positions of proposed revetment, groin ¾ And dredging zone
18 11/23/2009
MSS Traverse River Jetty
Tailings Are Washing Across Traverse & Tobacco Rivers
19 11/23/2009
Summary
¾ Historic mining is the dominant source of mercury to Lake Superior; voluntary industrial reppgjorting is just not workin g ¾ $15M Torch Lake Superfund Program covered interior stamp mill sites with soil layer; benthos not remediated (800+years); Hg methylation ¾ Mine tailings & smelter sites continue to contaminate many Lake Superior watersheds (U.S. & Canadian sides) ¾ Gay Site was not included in Torch Lake Project; tailings piles are currently contaminating miles of the Keweenaw Peninsula shoreline
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