Chapter 27 Minerals and the Environment

What is a Mineral? A substance formed by geological processes Nonrenewable Availability determines standard of living (Rock – aggregate of one or more minerals)

How Mineral Deposits Are Formed Ore Deposits – formed when metals are concentrated in unusually high amounts by geological processes Mineral resources are usually extracted from ore deposits Plate Boundaries – metals are precipitated and carried to the surface –Hg

How Mineral Deposits Are Formed Igneous Process – magma cools and then crystallizes –Diamonds Sedimentary Process – wind, water, and glaciers; sorting process –Sand and gravel Steam process sort heavy metals –Gold

How Mineral Deposits Are Formed Evaporation – minerals fall out as a precipitate –Salts Biological – can form minerals Weathering – concentrate minerals in the soil

Resources and Reserves Minerals are classified as: – Mineral Resources Elements, chemical compounds, minerals or rocks that can be extracted to obtain a usable commodity –Mineral Reserves The portion of the resource that is identified and from which usable materials can be legally and economically extracted at the time of evaluation

Availability of Mineral Resources When the availability of a mineral becomes limited, there are 4 possible solutions: 1. Find more sources 2. Recycle and reuse what has already been obtained 3. Reduce consumption 4. Find a substitute

Impacts of Mineral Development Environmental Impacts –Mining procedures Surface vs. Deep-mining –Waste Pollution

Impacts of Mineral Development Social Impacts –Increased demand for housing and services in mining areas –Economic stress of mining shutdown

Minimizing Environmental Impact of Mineral Development Environmental regulations at the federal, state and local levels On-site and off-site treatment of waste Practicing the 3 R’s of waste management

Minerals and Sustainability R-to-C Ratio –A measure of the time available for finding the solutions to depletion of nonrenewable resources –R = known reserves –C = rate of consumption High Fluctuation