Forensic soil provenancing in an urban/suburban setting: A simultaneous multivariate approach

Area of Science:

• Forensic science
• Geochemistry
• Mineralogy

Background:

• Soil is a crucial material for forensic and intelligence applications.
• Developing reliable soil provenancing methods is essential for evidence analysis.

Purpose of the Study:

• To develop and test an empirical soil provenancing method using compositional data.
• To evaluate the effectiveness of different analytical techniques for soil provenancing.

Main Methods:

• Collected 268 topsoil samples from North Canberra for compositional analysis.
• Utilized Fourier Transform InfraRed spectroscopy (FTIR), X-Ray Fluorescence (XRF), and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS).
• Employed a simultaneous provenancing approach using Spearman's correlation coefficients and interpolated raster grids.

Main Results:

• Fourier Transform InfraRed spectroscopy (FTIR) and X-Ray Fluorescence (XRF) demonstrated the highest precision and accuracy in provenance predictions.
• Maximizing the number of analytes and analytical techniques enhances soil provenancing capabilities.
• The empirical method showed promising results in test cases with simulated evidentiary samples.

Conclusions:

• The empirical soil provenancing approach is a valuable tool for forensic and intelligence applications.
• FTIR and XRF are recommended analytical methods for precise soil provenancing.
• Further research can refine this method for broader application in forensic investigations.