Environmental Geology

Mineral and Rock Resources


I. Mineral or rock resources are any material of value that is derived from rocks or minerals

Can separate these resources into three groups:

Overhead 1 - Per Capita use of mineral and rock resources

Point: Use of vast mineral resources is built into US economy. Our lifestyles are both energy- and resource-intensive.

Interesting statistics:

II. Formation of Ore Deposits

Terms to know:

Concentration of ore in rock determines whether it can be mined profitably.

Concentration = mass of ore / mass of rock body containing ore

Concentration factor = concentration of ore in a given ore deposit divided by the average concentration of that ore in continental crust. Concentration factor is a useful way to think about the enrichment of an ore body.


How do minerals become enriched above average crustal concentrations?

Processes can be grouped into four categories (study Table 14.4 and Pages 374-380 in Pipkin).

III. Extracting Mineral Resources: Environmental Consequences

Mineral extraction - the single most damaging environmental process undertaken by mankind.

Mineral resources typically extracted via

Minerals are separted from rocks using a variety of techniques (see text for details)

Crushed leftovers ( tailings) constitute about 90% of mine waste. Typically dumped into huge piles onto the landscape and are left there after the mine closes.

Environmental consequences of mineral extraction include

IV. Political Issues: In Wisconsin and Overseas

Flambeau and proposed Exxon/Rio Algom mines

Renewed interest in exploiting mineral resources in northern Wisconsin and upper Peninsula, both with long histories of mining copper, gold, silver, and now zinc. Controversy surrounds each proposed mine, with environmental, local, tribal, governmental, and industry groups all debating the issues and facts.

Open-pit mine near Ladysmith, Wisconsin - developed close to Flambeau river. Began shipping ore in 1993; will close in 1997 after four years of operation. No contamination of surface water or groundwater thus far. Under Wisconsin law, mining companies are liable in perpetuity for any environmental damage arising from their mining activities.

Exxon/Rio Algom have proposed new underground mine at the headwaters of the Wolf River. 55 million tons of zinc/gold/silver/copper in one-mile long volcanic intrusion. Requires pumping one million+ gallons per day of treated waste water 38 miles to the Wisconsin River. Forty million tons of tailings would be stored on the landscape above a plastic/clay liner and beneath a four-foot clay and soil layer.

Issues: Wisconsin DNR unable to identify one example of a sulfide mine freefrom adverse environmental consequences (out of more than 10,000 in this country. DNR maintains that the proposed mine will not affect the Wolf River watershed.

State of Wisconsin and Exxon/Rio Algom have been treating the question of whether a mine should be permitted as an engineering problem, i.e., can the appropriate engineering be done to ensure an environmentally-clean mine?

Citizen groups view the mine differently - ask whether mining is an appropriate use of this land and whether the inherent value of some natural sites exceeds their financial value.

Thus far, federal agencies (EPA and Dept. of Interior) have shown more awareness and concern for viewpoints of tribal and local citizens than have state and local government entities. Does state government respond to citizen's concerns or cater to business?

Web sites for Crandon mine:

Question: Does one risk a pristine resource even if assorted groups and models (all of which have proven imperfect in the past) suggest that the risk is minimal?

Conflict: If one doesn't accept mines, where will the resources that we demand to maintain our standard of living come from?

The Panguna Copper Mine of Bougainville, Papua New Guinea

Location - small island north of Papua New Guinea in the southwest Pacific. One of world's largest copper mines - provided 17% of PNG government's export income. Home to 14,000 Nasioi, indigenous tribe.

Environmental Record - horrendous - huge open-pit mine - 1.5 miles across, quarter-mile deep. Mine forcibly installed in midst of native's homeland, seriously disrupting their agriculture. In 1970, company began daily dumping of 130,000 tons of waste rock, silt, and chemicals into the nearby rivers (totaling some 600 million tons), leading to a social and ecological disaster. All aquatic life in the rivers was killed and seven years after the mine has been closed, the river is still biologically dead. A similar mine in Papua New Guinea has destroyed the nearby river, and the nearby tribe has filed a $4 billion claim against the mine for environmental damages.

Compensation to original landowners. $120 US per household for their land and to make transition to modern life! Only 8% of mine jobs went to natives - outside labor that was imported caused further social disruption.

Rebellion - In 1988, group of Nasioi marched on mine to demand more jobs, compensation, better basic services, and decrease in environmental impact of mine. Mine operators declared that the mine was not responsible for environmental problems. Several days later, Nasioi stole explosives from mine, blew up mine installations, and organized a rebel group that demanded $10 billion in compensation for the mine's devastation. They attacked and closed the mine in 1989, which has never been re-opened. Armed conflict between the government of Papua New Guinea and the Nasioi continues to this day.