Reserves and Resources: The term resources refers to the total resource and includes both renewable and non-renewable and discovered and undiscovered resources.  The term reserve refers to the portion of non-renewable resources that have been discovered and are exploitable using current technology under current economic and legal conditions.

Renewable energy resources include solar, wind, wood, and agricultural products (e.g. ethanol). Renewable energy sources generally have minimal environmental consequences.

Nonrenewable energy resources include fossil fuels (coal, oil, and gas), nuclear, and geothermal energy. For non-renewable resources we have to consider both the magnitude of the resource (reserves) and the environmental costs of exploitation.

Fossil fuels include coal, oil, and natural gas, but also include unconventional sources such as oil shale and tar sands. All of these sources are natural organic matter derived from ancient plant and animal life forms. Oil and gas are fluids and can migrate through permeable rock formations. Because of their low densities, oil and gas migrate upwards and can be trapped beneath impermeable barriers. Coal is the heavier and more complex hydrocarbon residue that does not migrate from the original source.

Nuclear fission energy comes from the splitting of uranium atoms.  The economic reserves of uranium on the earth are roughly equivalent to all of the exploitable energy from fossil fuels. Nuclear fission reactors produce energy in the form of electricity from the nuclear fission of 235U. Uranium as mined yields about 3 million times as much energy as an equivalent mass of coal. Natural uranium is about 0.7% 235U and 99.3% 238U. In the U.S., the percentage of the 235 isotope is increased or enriched to about 3.3% which is sufficient to sustain the nuclear chain reaction with ordinary water as the moderator. There are other types of reactors that use different moderators. It is also possible to convert the unused 238 isotope to plutonium which would increase the energy by a factor of 100 or so, but doing this is thought to have military consequences that are deemed unacceptable. About 30% of our electricity comes from nuclear power. In France they percentage is closer to 90%.

Nuclear fusion energy comes from the fusion of light elements like H and He and is the primary energy source of the sun. Although it does not produce tons radioactive waste products and the fuel is abundant and not radioactive initially, the reactor vessels would become radioactive and some radioactive tritium is produced. Experimental fusion reactors are nearly at the break-even point (produce more energy than they consume). It will be decades before they can compete with other sources economically.

Fossil fuels are not minerals; they have their name because they are derived from the remains of once-living organisms, and thus can be considered "chemical fossils." Two major groups of fossil fuels exist: coal and petroleum.

1. Coal - forms from the remains of plants. Great quantities of plants existed millions of years ago on Earth in "coal swamps." These plants lived and died, and their remains accumulated in the swamps. Instead of decaying or decomposing by the action of aerobic bacteria (bacteria which require oxygen to live), the plant debris accumulated due to anoxic (no oxygen) conditions in the swamp water. Over millions of years, the vegetable material was compressed by sediments deposited later and on top of the plant debris. Water was gradually squeezed out and the plant material progressively changed from organic debris-->peat-->lignite-->bituminous coal-->anthracite coal. At each step, the carbon content increased and the water content decreased. Bituminous coal is the common black coal with which everyone is familiar. Coal forms from the accumulation of plant material in great coastal swamps many millions of years ago. The plant debris did not decay due to the anoxic conditions of the swamp water. As other sediments were deposited on top of the plant material, its water was squeezed out and its carbon content was concentrated. The sequence of development is this: plant debris-->peat-->lignite coal-->bituminous coal-->anthracite coal. As the coal changes, it becomes richer in carbon and higher in energy content. Coal is also extremely abundant in the world; the U.S. has the world's largest accessible reserves of coal; they have enough to last about 200 years at current rates of use.

2. Petroleum - the word means "rock oil." There are two major forms of petroleum, crude oil and natural gas. (There are two minor types of petroleum, oil shale and tar sands.) Petroleum is the primary fuel of the industrialized world and, along with coal--the second most important fuel--constitute the main energy sources of human societies on Earth. Petroleum companies are among the largest corporations on the planet, and their geologists have the important responsibility of finding sufficient petroleum resources to keep human civilization going. Petroleum is derived from the cells of marine plankton, single-celled protozoa and protophyta (zooplankton and phytoplankton) that lived in ancient oceans millions of years ago. Their microscopic bodies existed in uncountable numbers; when they died, these bodies sank to the bottom and accumulated in the muds on the sea floor. As with coal, the plankton did not decay because there was not enough oxygen in the ocean water due to unusual anoxic conditions. The muds became enriched in organic compounds (molecules of carbon and hydrogen); when these muds lithified, they then became organic shales. At the same time, the shales were buried and the plankton-derived organic compounds were heated and pressurized, turning them into petroleum. Organic shales are known as source rocks, because they are the ultimate source of petroleum. The petroleum is squeezed out and travels by migration to porous and permeable sandstones and limestones known as reservoir rocks. The petroleum is held in the reservoir rocks by petroleum traps, and this is where it is found today by geologists.

Origin: Petroleum is produced when marine plankton die and their microscopic bodies accumulate in oceanic muds at the bottom of seas, oceans, and lakes many millions of years ago. Normally dead plankton decay, but if the waters are anoxic, the organic compounds will be preserved, since the decomposing bacteria are aerobic (require oxygen). The organic-rich muds become organic-rich shales during lithification; these shales are known as source rocks because they are the source of petroleum. As the shales are buried by other sediments and rocks, the organic compounds are altered by temperature and pressure and petroleum is produced. The petroleum migrates from the source rock to reservoir rocks, usually sandstone and limestone. Reservoir rocks have the porosity and permeability necessary to hold and transmit petroleum.

The petroleum accumulates in traps; know the different types: structural and stratigraphic.

Energy resources are measured in quad units which are based on the archaic BTU unit (British thermal unit). The US consumes about 84 quads per year. World oil reserves are about 10,000 quads. World natural gas reserves are about 7500 quads. Oil shale and tar sand estimated resources are about 13,500 quads.  Estimated coal reserves are about 135,000 quads.

Environmental problems exist for all fossil fuel resources. At the production and transportation stage, oil spills can cause extensive damage to plant and animal life. Coal is produced most economically from large strip mines. On burning all fossil fuels release CO2 and H2O to the atmosphere along with lesser amounts of SO2 and NOx. Sulfur and nitrogen oxides cause acid rain, and CO2 is a greenhouse gas. Coal also contains sulfur which when burned to SO2, causes acid rain.

The amount of CO2 in the atmosphere has been rising over the past 40 years. In 1958 it was about 315ppm, and today it is about 360ppm. Thus it has increased about 15% in 40 years. CO2 is a colorless, odorless, tasteless, poisonous gas.Animal life cannot exist in an atmosphere of >1% CO2 (10,000ppm).

CO2 is also a greenhouse gas, meaning that it absorbs energy in the infra-red wavelengths, and passes energy in the visible. The sun emits in the visible, and the earth emits in the infra-red because it is much cooler than the sun. Greenhouse gases in the atmosphere pass energy that comes in from the sun and block emission of energy from the earth's surface. If greenhouse gases accumulate in the atmosphere then the earth's surface temperature will increase. Other greenhouse gases include methane, nitrogen oxides and CFCs (chloro-fluoro-carbon).

But CO2 is the main greenhouse gas, and the increase is due primarily to the burning of fossil fuels. Photosynthesis by plants removes CO2 from the atmosphere and burning of that plant material releases it. In addition to atmospheric CO2 the earth has huge reservoirs of CO2 in carbonate rocks, and dissolved in sea water. The atmospheric buildup of CO2 may eventually limit our ability to utilize energy from fossil fuels.

Although no greenhouse gases are generated by nuclear power, there are other environmental problems that are potentially as serious. Mining U creates radioactive mine and mill wastes. Enriching the 235 isotope leaves tons of depleted 238 which is radioactive. Also, accidents at nuclear power plants can do massive environmental damage as we saw at Chernobyl in the Ukraine. The reactors also create tons of very highly radioactive fission products.   In the U.S., nearly all of the spent fuel from commercial power reactors is still at the reactor sites stored in huge water tanks.  Is there a better place to store it?

Petroleum is abundant in the world; we will not run out for over 100 years. However, we can experience disruptions in supply due to political and economic conditions--these are called energy crises. The U.S. is running out of oil, so they must import more from other countries; they currently import about 50% of their oil, and this greatly adds to their foreign trade deficit and balance of payments problem. We still have abundant natural gas, however, enough to last over 100 years at current rates of use.

Understand primary, secondary, and tertiary (enhanced) recovery.

Problems using fossil fuels: (1) burning fossil fuels causes air pollution; (2) fossil fuels are expensive; (3) fossil fuels are a nonrenewable resource; (4) crude oil is the most important fossil fuel, and the U.S. is running out of this and must import greater amounts. We will NOT run out for over 100 years and probably longer, since as fossil fuels become scarcer, their price will rise and this will automatically discourage consumption, decrease demand, and promote conservation. Artificial conservation is currently practiced by almost all industrialized countries except the U.S. by high taxes on gasoline. The U.S. and other countries are addicted to fossil fuels, since they are necessary to keep our civilization going.

We are not able to manufacture the chemical elements of the Periodic Table, so we have to go out and find them if we need them. Many of them have already been found, so we can also recycle stuff we've used previously.

Why do mineral deposits occur on Earth at all? If the Earth accreted from meteorites and the meteorites condensed from a gas phase with all of the elements mixed up together, what are the processes that concentrate similar elements to form economic deposits? For example, only one atom out of 500 million atoms in the crust is an atom of gold (Au). How, then, can nuggets of gold form that contain 1021 or 1022 (a few grams) atoms of gold?

The answer is that the igneous processes that operate on the planet set up huge distillation columns that concentrate similar elements. And the source of heat in the Earth is? . . . .  Also the weathering and transportation (erosion) processes at the surface can further concentrate some elements. And if we understand these processes pretty well, we will know where to look for the minerals we need. Assuming we've already checked available resources from recycling.

Mineral resources are commonly divided into metals and non-metals.

Non-metals include stone, sand and gravel, cement (a major source of CO2), salt, clays, phosphate rock (fertilizer) as well as others.  Demand for non-metals is increasing.

Metals include iron (steel), aluminum, copper, zinc, manganese, lead and others. Demand for new metals derived from ore deposits is decreasing, largely due to recycling.

Economic geology -- the study of valuable mineral deposits and the geologic conditions that form them

Exploration geology -- the science of searching for and discovering valuable mineral deposits

Mineral deposit -- rock or sediment that contains enrichment of one or more minerals

Mineral ore deposit -- rock or sediment that contains enrichment of one or more economically-valuable minerals

Mineral resource -- any actually or potentially valuable ore mineral resource

Mineral reserve -- identified ore mineral resource whose quantity and quality (grade) have been measured and which can be profitably mined under current economic, technological, and political conditions; a mineral resource becomes a reserve when (1) it has been geologically studied, mapped, and analyzed so that it grade and abundance are known, (2) it becomes technologically feasible to extract the ore minerals, and (3) the mineral's price on the world market is such that it becomes profitable to mine it

Ore minerals -- economically-valuable minerals in an ore deposit

Gangue minerals -- waste or left-over minerals remaining after an ore deposit is mined and processed and the ore minerals extracted

Mine tailings -- piles of gangue minerals that accumulate near a mining operation

Minerals can be divided into two main groups, metallic and nonmetallic:

Metallic minerals:

* iron

* gold

* silver

* copper

* aluminum

* tin

* zinc

* lead

* etc.

* building materials: sand (quartz), limestone (calcite), gravel, clay

* evaporite minerals: salt (halite), gypsum, borax, etc.

* gemstones: diamond, ruby, emerald, topaz, etc.

* lubricants: graphite, talc, etc.

* abrasives: garnet, diamond, quartz, etc.

* misc. rare earth minerals: lithium, beryllium, cesium, iridium, etc.

1. Hydrothermal Mineral Deposits -- Two types: (1) volcanogenic massive sulfides form at rift valleys along the axis of oceanic ridges: sea water seeps into the subsurface and is superheated by the magma body of the ridge; the superheated water dissolves metals (iron, copper, zinc, lead, gold, silver, magnesium, tin) and sulfur from the mafic igneous rocks, then this ion-rich solution issues forth from "black smokers" in the rifts, cools, and precipitates the metal and sulfur as metallic sulfides on the sea floor: pyrite, FeS; chalcopyrite, CuFeS; sphalerite, ZnS; galena, PbS, etc. (2) Any cooling igneous pluton can superheat the local groundwater and become a source of hydrothermal solutions. Most of the world's copper, lead, zinc, and tin deposits are hydrothermal in origin; examples include the Upper Pennisula of Michigan with many copper and silver mines, the lead and zinc mines of Joplin, Missouri, and the famous copper mines of the Rocky Mountains in Montana and Utah.

2. Metamorphic Mineral Deposits -- Regional metamorphism in mountain belts at convergent plate boundaries creates many economically-valuable minerals; these include graphite, garnet, talc, and marble. Any mountain belt or shield area has mines containing metamorphic minerals; e.g. the Canadian Shield, the Appalachian Mountains, the Llano Uplift of Texas.

3. Magmatic Mineral Deposits -- Crystallization of magmatic bodies (plutons) leads to the concentration of many valuable minerals. There are three types:

* Pegmatites -- extremely-coarse crystals of any mineral, some quite rare and valuable; e.g. King's Mountain, North Carolina (lithium), Tanco Pegmatite, Canada (cesium)

* Layered Igneous Intrusions -- crystal settling during magmatic cooling can sometimes concentrate a valuable mineral in layers in igneous rocks; the best examples are the chromite ore layered intrusions of the Bushveld Igneous Complex of South Africa and the Great Dike of Zimbabwe--most of the world's chromium comes from here. Another example is the Sudbury Complex of Ontario, source of most of the world's nickel.

* Kimberlites -- These are funnel-shaped, pipelike bodies of igneous rock that originate deep within the mantle, more than 150 km in depth. The magma rises upward in an explosion and carries with it broken fragments of mantle rock called xenoliths (Greek, xeno=foreign, lith=rock). The most important mineral constituent of kimberlites is diamond; diamonds only form in the mantle at depth greater than 150 km. The best kimberlite pipes are at Kimberley, South Africa, and are mined for diamonds. Other kimberlites are found in Arkansas, Russia, Canada, etc.

4. Sedimentary Mineral Deposits -- Sedimentary Rocks, Natural Resources, and Fossil Fuels

Sedimentary rocks are the source of many natural resources. These include building materials (sand, gravel, and lime for cement and concrete), iron ores, phosphates, many metals (copper, gold, silver, tin, aluminum, etc.), and the fossil fuels. An important iron ore, the banded iron formation, is sedimentary in origin. It is a layered rock, with alternating bands of gray hematite and red jasper. Hematite is an iron oxide, an excellent iron ore. The bands were formed by layered bacterial mats of cyanobacteria; these organisms were photosynthetic; they produced oxygen which oxidized the free iron cations in the ocean during Earth's early history more than 2 billion years ago. The mats trapped mud in layers and slowly grew with the oxidized iron trapped in the layers. An enormous variety of econcomically-valuable minerals are formed by simple sedimentary processes. These include the following:

*Evaporites -- Lake-water evaporites include sodium carbonate, sodium sulfate, and borax, e.g. the Green River Basin lakes in Wyoming and Death Valley, California. Marine evaporites include halite (ordinary salt) and gypsum (used to make sheetrock); great salt deposits are found in Michigan and Texas.

*Chemical Precipitates -- Marine phosphates contain the element phosphorus, a primary component of fertilizer. Most of the world's great iron deposits are found in banded iron formation, a layered formation of iron ore, formed by precipitation of hematite (iron oxide), jasper (iron silicate), and goethite (iron carbonate) through the action of photosynthesizing cyanobacteria living in flat bacterial mats on the sea floor 2-3 billions of years ago. The best example of banded iron formation are the Lake Supior-type iron ores of northern Minnesota, the Upper Pennisula of Michigan, and Western Australia.

*Stratabound Deposits -- Some of the world's most important ores of lead, zinc, and copper are found as metallic sulfides formed by hydrothermal action but enclosed by sedimentary strata. Vast deposits of pure sandstone serve as a supply of quartz for glass making; limestone serves as a souce of calcite for cement; stream gravels serve as a source of gravel for concrete; and clay deposits serve as a source of clay for ceramics. The Miami River is a source of sand and gravel; the St. Peters Sandstone of Illinois is a source of pure quartz for glass making.

5. Placer Mineral Deposits -- A lag-deposit of heavy minerals that have been concentrated by mechanical processes is called a placer. The concentration usually happens as a result of the winnowing action of stream currents or ocean waves. Stream placers are famous as a source of gold, such as the streams of the Rocky Mountains and Sierra Nevada. Beach placers in Namibia (southwest Africa) are famous for the wave-concentration of diamonds weathered from kimberlite deposits in the interior to the east. Most of the world's gold comes from ancient "fossil" placers around the edge of the Witwatersrand Basin in South Africa.

6. Residual Mineral Deposits -- These are mineral deposits concentrated by chemical weathering. Certainly the best example is the weathering of tropical laterite soils to form bauxite, the ore of aluminum. Tropical weathering concentrates limonite (iron oxide) and gibbsite (aluminum oxide) in laterites; aluminous laterites are called bauxites and are the source of the world's aluminum.

7. Marine Mineral Deposits -- Metal-rich concretions called manganese nodules are found on the sea floor in some places; these could serve as a source of manganese, iron, cobalt, nickel, and copper if economic conditions permit their recovery at a profit.

Depletion of Mineral Resources -- Ore minerals are finite, nonrenewable resources; all are currently being exploited at nonsustainable rates. Minerals are distributed unevenly on Earth; only six countries have the majority of valuable ore minerals: United States, Canada, Russia, Australia, South Africa, and Brazil. These six countries are large and have the unique geological conditions which lead to mineral enrichment and the formation of metallogenic provinces.

Extraction and processing of minerals creates waste materials in the form of waste rock, mine tailings, and waste chemicals. These must be disposed of in a safe manner, but often are not. Spoil piles are waste rock removed and discarded to expose ore minerals; tailings piles are gangue minerals discarded after the ore rock has been crushed and the ore minerals concentrated; chemical waste is left over after the ore minerals are processed and purified. The cheapest thing to do is dump these on the surface and then ignore them. Rain water, however, enters these spoil piles, tailings piles, and chemical waste dumps and leaches toxic and hazardous elements; these harmful elements are carried away and can do their damage somewhere else. For example, sulfur is often leached from spoil and tailings piles; sulfur plus water creates sulfuric acid, and these acidic waters cause acid mine drainage, a severe problem that causes acidification of streams and lakes throughout the American West. Acidic runoff can be devastating to natural ecosystems. Heavy metals--such as lead, cadmium, selenium, and mercury--leached from mine waste can cause contamination of the groundwater and poisioning of humans.

To prevent such environmental disasters, mines must be regulated so that their waste deposits are kept isolated from the groundwater and surface water. After a mine is shut down, the site should be cleaned up and rehabilitated, a process called mine site decommissioning. Part of this process is to prevent mine spoil, tailings, and waste from coming into contact with water. Modern countries today require mine site decommissioning as a regulatory matter, but thousands of old, polluted mines still exist that were abandoned before decommissioning laws went into effect. Colorado alone has hundreds of these abandoned mines, all emitting some form of toxic waste or acid mine drainage; these must be cleaned up with tax dollars.