Light absorption spectroscopy (LAS) is a mineral-identification technique that measures the absorption spectrum, in visible and near-infrared bands (350-2500 nm), of a light beam reflected from any surface. LAS is rapid (<30 s), nondestructive, and usable on irregular, sawed, or powdered rock surfaces. Diagnostic absorption bands allow identification of several minerals, including opal, calcite, smectite, and illite. These four minerals, which are indicators of paleoceanographic and paleoclimatic variation, are the most abundant minerals in the sediments cored during Ocean Drilling Program Leg 199. Consequently, we have developed techniques for routine shipboard LAS measurements and for determination of mineral percentages from LAS spectra. The mineralogy calculation is based on a combination of multiple regression and matrix inversion on spectra from equatorial Pacific standards with known mineral concentrations.
1Examples of how to reference the whole or part of this volume can be found under "Citations" in the preliminary pages of the volume.
2Department of Geology and Geophysics, University of Utah, Salt Lake City UT 84112, USA.
Correspondence author: mvandenberg@mines.utah.edu
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