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Glossary

Macerals
Equivalent to minerals in rocks, macerals form from the coalification of the various parts of plants. There are three major groups of macerals: Vitrinite – the most abundant maceral is the result of the decomposition of the cell walls of plant material (essentially decomposed cellulose and lignin). Exinite – composed of spores, cuticles (the outer surfaces of leaves), resins, and waxes. Inertinite – mostly charcoal, which usually forms in layers resulting from fires that periodically sweep through wetlands.

Macrophytes
A member of the macroscopic plant life, especially of a body of water.

Magma
Any molten silicate(rock) material, whether below the surface or on top. Magma may be completely liquid or a mixture of liquid rock, dissolved gases and crystals. Igneous rocks are derived from magma through solidification and related processes or through eruption of the magma at the surface. Molten rock that flows out onto the Earth’s surface is called lava (see).

Magnetic basement
Magnetic basement is usually equated to crystalline (felsic and mafic) or sometimes, metamorphic basement. It is the unconformity upon which an essentially non-magnetic sedimentary section has been deposited. Large exposures of basement (e.g., the Canadian Shield) show it to be lithologically and magnetically heterogeneous. Very thick sequences of highly magnetic volcanics may sometimes be considered equivalent to a magnetic basement.

Magnetic field
Region around a body in which a magnetic force is detected. Fairly weak magnetic fields are generated by dynamo effects inside planets and moons. Magnetic fields more than one billion times stronger may be generated in stars and galaxies. These are capable of controlling the motion of ionised gas and even the shape of objects. (source: European Space Agency)

Magnetic force
One of the fundamental forces of Nature. It is a physical phenomenon which arises as a result of moving electric charge and which results in attractive and repulsive forces between objects.

Magnetometer
An instrument for measuring the magnitudo and the direction of a magnetic field.

Major historical resource
Remarkable element for its historical and artistic attributes within a landscape evaluation.

Major natural resource
Remarkable element for its natural attributes within a landscape evaluation.

Majors
Multinational oil companies, which by virtue of size, age and/or degree of integration, are among the pre-eminent firms in the international petroleum industry (source: Reuter Financial Glossary).

Malleability
Capable of being hammered or rolled into a shape without breaking.

Manure
Excreta of animals, with or without an admixture of bedding or litter, fresh or at various stages of decomposition or composting. In some countries the term may denote any fertilizer material.

Manured
Referring to fields treated with fertilizers as manure (see).

Marine snow
The remains of plants and animals that drift down from the sunlit surface waters of the ocean to the depths. Marine snow is the base of most deep-sea food chains.

MARPOL 73/78 convention
MARPOL 73/78 is the International Convention for the Prevention of Pollution from Ships 1973 as modified by the Protocol of 1978. MARPOL contains six annexes covering pollution by oil, noxious liquids carried in bulk, harmful substances in packaged form, sewage, garbage and air pollution. MARPOL applies to shipping of various types and in part to oil rigs and production installations.

Marsh
Soft, wet low-lying land that provides an important ecosystem for a variety of plant and animal life. Marshes may be either fresh or saltwater, tidal or non-tidal. (See: wetlands)

Massives
A French term, adopted in geology and physical geography for a mountainous mass or group of connected heights, whether isolated or forming part of a larger mountain system. A “ massif” is more or less clearly marked off by valleys.

Maximum Efficient Rate (MER)
The maximum rate at which natural gas and crude oil can be produced without excessive decline of reservoir energy or a loss in ultimate production.

MBDE (Million Barrels A Day Of Oil Equivalent)
Million barrels per day of oil equivalent.

Mechanical properties
Those properties of a material that are associated with elastic and inelastic reaction when force is applied. These properties, which can also involve the relationship between stress and strain, include abrasion resistance, ductility, elasticity, creep, hardness, impact resistance, friction resistance, stiffness and strength.

Mechanization
Replacement of manual work with machines in the development of activities.

Mediterranean
Relates to the body of water that separates Africa, Europe and Asia or to the land and people around it.

MER (Maximum Efficient Rate)
The maximum rate at which natural gas and crude oil can be produced without excessive decline of reservoir energy or a loss in ultimate production.

Mercaptan
A highly concentrated odorant that is injected into natural gas before it enters a utilities distribution system. Mercaptan gives off a foul smell, reminiscent of rotten eggs.

Mesosphere
The atmospheric layer between the stratosphere and the thermosphere. Located at an average elevation between 50 and 80 km above the earth’s surface.

Metabolism
The process of chemical change by which energy is provided in living cells.

Metal leaching
The extraction of soluble metals by percolating solvents. Leaching may be natural or induced. Primary mineral weathering commonly accelerates metal dissolution and removal in minesite drainage.

Metallurgy
The science and technology of metals and alloys. Also the process of extracting metals from their ores.

Metamorphic rock
A rock that has undergone chemical or structural changes produced by increase in heat or pressure, or by replacement of elements by hot, chemically active fluids.

Meteorite
A metallic or stony (silicate) body that has fallen on Earth (or other planetary body) from outer space. Most meteorites come from asteroids, but a small number come from the Moon or Mars (see SNC meteorites). Meteorite types include: iron, stony iron, chondrite, carbonaceous chondrite, and achondrite. Smaller than 1 mm are called “micrometeorites.” SNC meteorites: one of the 12 meteorites thought to have come from Mars. The letters SNC stand for the three types of meteorites: Shergottites, Nakhlites, and Chassigny.

Meter [m]
The meter is the basic unit of length. It is the distance light travels, in a vacuum, in 1/299792458th of a second.

Methane CH4
The simplest hydrocarbon and the main component of natural gas, composed of four hydrogen molecules attached to one carbon molecule; methane is also produced when organic matter decomposes . Pure methane has a heating value of 1,1012 Btu per standard cubic foot.

Methane pipeline
A continuous pipe conduit, complete with such equipment as valves, compressor stations, communications systems, and meters, for transporting natural gas and/or supplemental gaseous fuels or processing plant to another pipeline or to points of use. Also refers to a company operating such facilities.

METHANOL CH3-OH
A clear, colourless, very mobile liquid that is flammable and poisonous; used as a fuel and fuel additive, and to produce chemicals. It’s formed by catalytically combining carbon monoxide (CO) with hydrogen (H2) in a 1:2 ratio, under high temperature and pressure. Commercially it is typically made by steam reforming natural gas. Methanol is also formed in the destructive distillation of wood. (Also known as Methyl Alcohol, Wood Alcohol).

Methylterbutylether
An ether manufactured by reacting methanol and isobutylene. The resulting ether has a high octane and low volatility. MTBE is a fuel oxygenate and is permitted in unleaded gasoline up to a level of 15 percent. It is one of the primary ingredients in reformulated gasolines.

Metropolis
Highly density populated city and widely extended. Usually the main city or capital of a country or region. In ancient Greece the metropolis just belonged to the “mother land” (Greece) in opposition to other towns, although wide and largely populated, raised on the colonies’ land.

Microbe
Microbe is another word for microorganism; any organism too small to be visible to the naked eye, e.g. bacteria, viruses, protozoans, some fungi, and some algae are all microorganisms.

Microclimate
A localized area or habitat that has a uniform climate.

Microorganism
A microscopic organism including bacteria, protozoans, yeast, viruses and, algae.

Micropaleontolgy
A branch of paleontology that deals with the study of fossils too small to be observed without the aid of a microscope; the study of microfossils.

Migration
The movement of animals in response to seasonal changes or changes in the food supply. Examples of animals that migrate include salmon, monarch butterflies, buffalo, and elephants.

Mimicry
A phenomenon in which one species benefits by a superficial resemblance to an unrelated species. A predator or species of prey may gain a significant advantage through mimicry.

Mine
A plant built to extract an ore or mineral substance either underground or from the surface. When the ore is extracted underground, the mine needs a system of excavations in the rock to gain access to the ore areas. When the ore is mined from surface, the ore is extracted from one or several pits.

Mitigation measure
Measures or actions undertaken in order to lessen the harmful effects of environmental disasters and hazards, through replacement, restoration, compensation or any other means.

Molecule
A group of atoms (see) bonded together. It is the smallest part of a substance that retains the chemical properties of the whole.

Molluscs
An organism in the phylum Mollusca (for example, snails, clams, or squids), whose soft, unsegmented body parts are frequently enclosed in a shell.

Monera
One of the five Kingdoms which contains all prokaryotes (see). It contains archaebacteria, eubacteria and cyanobacteria. The first life form emerged over 3,500 Mya were the members of this Kingdom from which eukaryotes (see) evolved.

Monitoring
“Continuous or frequent standardized measurement and observation of the environment (air, water, land/soil, biota), often used for warning and control.” (source: United Nations, Glossary of Environment Statistics).

Monoculture
A pattern of crop or tree production that relies on a single plant variety.

Montreal Protocol
The discovery of an ozone hole over Antarctica prompted action to control the use of gases which have a destructive effect on the ozone layer. From this concern emerged the Montreal Protocol on substances that deplete the ozone layer, signed by 24 countries in 1987. It came into force in 1989 and has since been ratified by 120 countries. The original agreement was to control and phase out the production and supply of ozone depleting chemicals, specifically CFCs (chlorofluorocarbons) and derivatives. A meeting in 1992 was held in Copenhagen to revise the Protocol. This meeting agreed to bring forward the phase out of halons (see) to 1994, and CFCs and other halocarbons to 1996. These targets have since been met.

Moraine
Accumulations of poorly sorted glacial materials (till) transported by glacial ice. Moraines can form in many ways. Some moraines form in front of a glacier (terminal or end moraine), along the side of a glacier (lateral moraine), or under a glacier (ground moraine).

Mouth
The outfall at the lower end of a river or stream, where flowing water is discharged, as into a lake, sea, or ocean: Example: the mouth of the Nile.

Mucilage
Gelatinous secretions and exudates produced by plant roots and many microorganisms.

Municipal Solid Wastes (MSW)
Household waste and other wastes collected by a waste collection authority or its contractors, such as municipal parks and gardens waste, beach cleansing waste and any commercial and industrial waste for which the collection authority takes responsibility.

Mutagen
A substance or agent that causes genetic mutations, or chemical alteration of the genetic material, DNA. X rays and and some chemicals are mutagens.

Mutation
The process through which genes undergo a structural change.

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