A mafic, coarse-grained, plutonic igneous rock consisting mainly of Ca-plagioclase feldspar, pyroxene and possibly olivine, but no quartz. Gabbros form from the slow crystallization of magma, which is basaltic in composition.

    Dark, medium- to coarse-grained, intrusive mafic igneous rock, commonly massive-appearing, generally lacking layering or banding; composed primarily of clinopyroxene and plagioclase; often altered.equivalent of basalt or diabase.

    Streams that gain water from the inflow of groundwater through the streambed. Reference: Tarbouk, E.J. & F.K. Lutgens, (2006), EARTH, 8th edition, Pearson Education International.

    A highly penetrating type of nuclear radiation, similar to x-rays and light, except that it comes from within the nucleus of an atom, and, in general, has a shorter wavelength. Gamma rays emission is a decay mode by which excited state of a nucleus de-excite to lower (more stable) state in the same nucleus. In our diagrams.

    (a) A group of minerals of formula: A3B2(SiO4)3, where A= Ca, Mg, Fe+2, and Mn+2, and B = Al, Fe+3, Mn+3, V+3, and Cr. (b) Any of the minerals of the garnet group, such as the end members almandine (Fe-Al). andradite (Ca-Fe), grossular (Ca-Al), pyrope (Mg-Al), spessartine (Mn-Al). uvarovite (Ca-Cr). and glodmanite (Ca-V).-Garnet is a brittle and transparent to sub transparent mineral, having a vitreous luster, no cleavage. and a variety of colors, dark red being the most common. It occurs as an accessory mineral in a wide range of igneous rocks, but is most commonly found as distinctive euhedral isometric crystals in metamorphic rocks (gneiss, mica schist, eclogite); it may also be massive or granular. Garnet is used as a semiprecious stone and as an abrasive.

    This powerful technique is particularly suitable for the analysis of mixtures of volatile and low relative molecular mass compounds (< 800) such as hydrocarbons, fragrances, essential oils and relatively non-polar drugs. GC/MS with capillary column separation and electron (impact) ionization (EI) is available within the Mass Spectrometry Facility.

    RAE Systems' large selection of Colorimetric Gas Detection Tubes offer quick, on-the-spot measurements of many gases and vapors at low cost. The tubes are easy to read with a sharp, clear color change and provide accuracy with no need for calibration.

    An ionization chamber with its vacuum and its applied potential so adjusted that a gamma ray or other ionizing particle passing through it causes a momentary current to flow. The surge of current can be amplified and counted so as to measure the intensity of radioactivity in the vicinity of the chamber.

    A prefix meaning "Earth" Reference: Bates, R.L. & J.A.Jakson, GLOSSARY OF GEOLOGY, Second Edition, American Geology Institute, 1980

    Relating to the chemistry of rocks. Geochemistry is the branch of science dealing with the chemistry of the Earth.