Validity of color examination for forensic soil identification

• Published in: Forensic science international 1996-12, Vol.83 (3), p.201-210
• Main Authors: Sugita, Ritsuko, Marumo, Yoshiteru
• Format: Article
• Language: English
• Subjects: Color measurement; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Euclidean distance; Exact sciences and technology; Forensic soil identification; Pollution, environment geology; Soil; Soils; Surficial geology
• ISSN: 0379-0738; 1872-6283
• DOI: 10.1016/S0379-0738(96)02038-5

The validity of a multiple measurement procedure for forensic soil identification was studied using 73 soil samples from an area where volcanic ash soils, alluvial soils and residual soils dominate. Soil color was measured by comparison to Munsell color charts after each of several treatments: (1) air-drying, (2) moistening, (3) organic matter decomposition, (4) iron oxide removal, and (5) ashing. In addition, the colors of the clay fractions were observed after organic matter decomposition and after iron oxide removal. Although only about 70% of soils could be differentiated by comparing the colors of air-dried samples, combining color measurements on soils after air-drying and moistening, and on the clay fraction after organic matter decomposition and iron oxide removal enabled us to differentiate 97% of soil samples. Adding color measurements of ashed soil to the above procedure did not provide any further improvement in the discriminatory power of the multiple color measurement.