1. Abandoned Mines: Effects on stream water geochemistry Fall, 2003 Serena NW Hollmeyer

2. Questions... What effects to abandoned mines have on pH and conductivity? What effects will abandoned mines have on dissolved metal species downstream? Where are the metals seen downstream coming from? What impact does pH have on metal dissolution?

3. Sample site locations: Belvidere Asbestos Mine, Eden Mills, VT. Ely Copper Mine, Vershire, VT. MacIntyre Titanium Mine, Tahawus, NY.

4. Belvidere Asbestos Mine Eden Mills, VT. Asbestos mine 1960-1993 Serpentine, amphibolite, muscovite schist. Drains into Dark Branch and Gihon River

5. Ely Copper Mine Vershire, VT. 1821-1950 Weakly calcareous mica schist with amphibolite and acicular amphibolite. Pyrite occurrences. Drains into Schoolhouse Brook (Upstream and downstream samples)

6. MacIntyre Titanium Mine Tahawus, N.Y. 1941-1982 Ilmenite and magnetite Drains into Opalescent River.

7. Methods Samples collected, filtered and acidified. pH and conductivity measured using digital meters. Samples analyzed using inductively coupled plasma optical emission spectrometer (ICPOES). Looked for 24 different metals.

8. Belvidere Data

9. Belvidere Metals

10. Ely data

11. Ely metals

12. MacIntyre data

13. MacIntyre Metals

14. Analysis: pH was lowest at Ely (expected due to sulfidic mineral exposures increasing acidity) Metals were most mobile at Ely, due to low pH? Na, Ca, and Mg levels elevated at each site, related to bedrock weathering?

15. Belvidere samples and possible sources of metals: Amphibole Serpentine Calcic filling of fractures? Road salt runoff?

16. Ely samples and possible sources of metals. Calcareous bedrock Copper ore Road salt? Amphibole Feldspar Associated iron ore Mica

17. MacIntyre samples and possible sources. Feldspar weathering (no road salt input) Ilmenite

18. Conclusions pH was lower at sulfidic site. Conductivity was highest in pit lakes or drainages Lower pH created conditions condusive to metals leaching Bedrock geology ultimately determined metals available for leaching. Bedrock geology also determined pH, the controlling factor in leaching of metals.

19. Questions?