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Kansas Geological Survey, Public Information Circular (PIC) 16


Aeromagnetic survey: A survey made with a magnetometer carried on an airplane. A magnetometer measures the earth's magnetic field and its changes. Rocks containing larger amounts of magnetic minerals register a higher response on the magnetometer.

Clinopyroxene: A group name for a number of pyroxene minerals that have similar crystal forms. They are silicates commonly containing aluminum, magnesium, calcium, and iron in their crystal structures.

Crust: The outermost layer or shell of the earth, representing less than 0.1% of the earth's total volume.

Garnets: A group of silicate minerals of which the dark red- to black-colored mineral pyrope is the typical garnet occurring in kimberlites. Pyrope is a silicate mineral containing magnesium and aluminum in its structure.

Igneous rock: A rock that solidified from molten or partly molten material.

Ilmenite: An opaque, black mineral containing iron and titanium.

Magma: Naturally occurring molten rock material, generated within the earth and capable of being intruded into other rocks or extruded onto the surface of the earth.

Mantle: The zone of the earth below the crust and above the core.

Olivine: An olive-green, silicate mineral rich in magnesium and iron. It is a common rock-forming mineral in the lower part of the crust and the upper mantle.

Peridotite: A general term for a coarse-grained igneous rock composed chiefly of the mineral olivine, with or without other magnesium-rich, dark-colored minerals.

Sedimentary rocks: A rock resulting from the consolidation of loose sediment that has accumulated in layers.

Ultrabasic: A rock containing virtually no quartz or feldspar and made up primarily of iron- and magnesium-rich minerals.

Kansas Geological Survey, Public Outreach
Web version July 2000