@article{385571c42fd84c009725dc86536fd1e2,
title = "Forensic soil provenancing in an urban/suburban setting: A sequential multivariate approach",
abstract = "Compositional data from a soil survey over North Canberra, Australian Capital Territory, are used to develop and test an empirical soil provenancing method. Mineralogical data from Fourier transform infrared spectroscopy (FTIR) and magnetic susceptibility (MS), and geochemical data from X-ray fluorescence (XRF; for total major oxides) and inductively coupled plasma-mass spectrometry (ICP-MS; for both total and aqua regia-soluble trace elements) are performed on the survey's 268 topsoil samples (0–5 cm depth; 1 sample per km2). Principal components (PCs) are calculated after imputation of censored data and centered log-ratio transformation. The sequential provenancing approach is underpinned by (i) the preparation of interpolated raster grids of the soil properties (including PCs); (ii) the explicit quantification and propagation of uncertainty; (iii) the intersection of the soil property rasters with the values of the evidentiary sample (± uncertainty); and (iv) the computation of cumulative provenance rasters (“heat maps”) for the various analytical techniques. The sequential provenancing method is tested on the North Canberra soil survey with three “blind” samples representing simulated evidentiary samples. Performance metrics of precision and accuracy indicate that the FTIR and MS (mineralogy), as well as XRF and total ICP-MS (geochemistry) analytical methods, offer the most precise and accurate provenance predictions. Inclusion of PCs in provenancing adds marginally to the performance. Maximizing the number of analytes/analytical techniques is advantageous in soil provenancing. Despite acknowledged limitations and gaps, it is concluded that the empirical soil provenancing approach can play an important role in forensic and intelligence applications.",
keywords = "compositional data analysis, geochemical mapping, geographic information system, interpolation, soil forensics, soil properties, uncertainty",
author = "{de Caritat}, Patrice and Brenda Woods and Timothy Simpson and Christopher Nichols and Lissy Hoogenboom and Adriana Ilheo and Aberle, {Michael G.} and Jurian Hoogewerff",
note = "Funding Information: We would like to express our gratitude toward Australian Federal Police (AFP) and Geoscience Australia (GA) management for allowing the first author?s 2017-2018 secondment to the AFP to take place. In particular, Eric Wenger, Sarah Benson, and Kate Sloan at the AFP, and Karol Czarnota and Richard Blewett at GA, were supportive of the secondment. Discussions with the AFP Chemical Criminalistics and Documents Forensic Team members influenced the development of the project. At GA, Phil Main provided access to data analysis scripts, and the Inorganic Laboratory Team provided access to instruments and technical support, which are gratefully acknowledged. James Robertson formerly from the National Centre for Forensic Studies, University of Canberra (UC), is thanked for his support for this collaborative work. Simon Foster provided access to the UC ICP-MS instrument for the aqua regia analyses. Andrew Roberts, Brad Pillans, and Xiang Zhao facilitated access to the magnetic susceptibility laboratory at the Australian National University. We thank all private landowners and the ACT Government for granting access to their property, public lands, and nature reserves for sampling purposes. Internal and journal reviewers and editor are acknowledged for their constructive recommendations that improved the original manuscript. PdC publishes with permission from the Chief Executive Officer, Geoscience Australia. Publisher Copyright: {\textcopyright} 2021 Commonwealth of Australia. Journal of Forensic Sciences published by Wiley Periodicals LLC on behalf of American Academy of Forensic Sciences",
year = "2021",
month = sep,
doi = "10.1111/1556-4029.14727",
language = "English",
volume = "66",
pages = "1679--1696",
journal = "Journal of Forensic Sciences",
issn = "0022-1198",
publisher = "Wiley-Blackwell",
number = "5",
}