N Electrode – Potential electrode distant from the A electrode in a resistivity device.
National Instrument 43-101 – NI 43-101 is the Canadian classification scheme used for the public disclosure of information relating to mineral resources. The National Instrument guideline is applicable to the technical disclosure about mineral properties of all public companies trading on stock exchanges which operate under the supervision of the Canadian Securities Administrators.
Native Metal – Natural deposit of a metallic element in pure metallic form that is neither oxidized nor combined with sulfur or other elements.
Neap Tide – Tide cycle of unusually small amplitude, which occurs twice monthly when the lunar and solar tides are opposed, or put another way, when the gravitational pull of the Sun is at right angles to that of the Moon.
Nebula – Immense, diffuse body of interstellar gas and dust that has not condensed into a star.
Nebular Hypothesis – Theory of the formation of the planets that states that a rotating nebula contracted and was then torn into fragments by centrifugal forces, with planets condensing from the fragments.
Neogene – Period from 23.03 to today. This is the new name given to the time starting from the Miocene Epoch to today.
Neoproterozoic – Era from 1000 to 542 mya within which there are three periods: 1) Tonian, 2) Cryogenian, and 3) the Ediacaran periods.
Nesosilicate – Mineral with isolated silicate tetrahedra..
Net Smelter Return Royalty – NSR is a type of royalty due or payable by miner of metals based on gross metal production from the property. The royalty paid is calculated net of certain limited costs including certain specific agreed upon costs such as smelting, refining, transportation and insurance.
Neutron – Electrically neutral elementary particle in the atomic nucleus having the mass of one proton.
Neutron-Activation Analysis – Method of identifying isotopes of an element by bombarding them with neutrons and observing the characteristic radioactive decay products emitted.
Neutron Log – Neutrons from an isotopic source are measured at one or several detectors after they migrate through material in, and adjacent to, the borehole.
NI 43-101 – National Instrument 43-101is the Canadian classification scheme used for the public disclosure of information relating to mineral resources. The National Instrument guideline is applicable to the technical disclosure about mineral properties of all public companies trading on stock exchanges which operate under the supervision of the Canadian Securities Administrators.
Non-Aqueous-Phase-Liquid – Elements or compounds in the NAPL liquid phase other than water. This could include such items as petroleum hydrocarbons, like gasoline, and solvents such as trichloroethylene.
Non-Unique – Geophysical interpretation and mathematical modeling, where a problem for which two or more subsurface models satisfy the data equally well is known as non-unique. Such a problem has at least two equally valid solutions and could in fact have an infinite number of solutions. Geophysicists must wrestle with this concept of non-uniqueness every time they tackle a geophysical problem which in real-life is always an under-determined problem where they have more unknowns than data. In such situations, we can have an infinite number of mathematically valid earth models that explain the same geophysical data.
Noise – Unwanted signal or disturbance that is not part of signal from a specified source such as in induced polarization surveys where noise may result from interference of power lines, generator motors, atmospheric electrical discharges, and so on.
Norite – Mafic intrusive igneous rock composed largely of calcium-rich plagioclase and olivine.
Normal Fault – Dip-slip fault in which the block above the fault has moved downward relative to the block below.
Normal Log – Quantitative-resistivity log which employs spacings of between 4 and 64 inches to investigate different volumes of material around the borehole.
Normal Moveout Corrections – Time shift corrections to reflection arrivals because of variation in shotpoint-to-geophone distance or offset. The amount of shift depends on 1) length of the ray path from shot to reflection point to receiver, and 2) velocity of the material traversed.
NSR – Net Smelter Return Royalty is a type of royalty due or payable by miner of metals based on gross metal production from the property. The royalty paid is calculated net of certain limited costs including certain specific agreed upon costs such as smelting, refining, transportation and insurance.
Nuclear Log – Logs using nuclear reactions either measuring response to radiation from sources in the probe or measuring natural radioactivity present in the rocks.