TY - JOUR
T1 - Forensic soil provenancing in an urban/suburban setting
T2 - a simultaneous multivariate approach
AU - de Caritat, Patrice
AU - Woods, Brenda
AU - Simpson, Timothy
AU - Nichols, Christopher
AU - Hoogenboom, Lissy
AU - Ilheo, Adriana
AU - Aberle, Michael G.
AU - Hoogewerff, Jurian
N1 - Publisher Copyright:
© 2022 Commonwealth of Australia. Journal of Forensic Sciences published by Wiley Periodicals LLC on behalf of American Academy of Forensic Sciences.
Funding Information:
We would like to express our gratitude toward the Australian Federal Police (AFP) and Geoscience Australia (GA) management for allowing the the first author’s 2017-2018 secondment to the AFP to take place. In particular, Vincent Otieno-Alego, Kate Sloan, Eric Wenger, and Sarah Benson 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, while Stewart Gilmore, Tara Webster, and Simon Webber from the Inorganic Laboratory provided access to instruments and technical support, which are all 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. We thank all private landowners and the ACT Government for granting access to their property, public lands, and nature reserves for sampling purposes. Internal (GA) and journal reviewers and editors are acknowledged for their constructive recommendations that improved the original manuscript. PdC publishes with permission from the Chief Executive Officer, Geoscience Australia.
Publisher Copyright:
© 2022 Commonwealth of Australia. Journal of Forensic Sciences published by Wiley Periodicals LLC on behalf of American Academy of Forensic Sciences.
PY - 2022/5
Y1 - 2022/5
N2 - Soil is a ubiquitous material at the Earth's surface with potential to be a useful evidence class in forensic and intelligence applications. 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 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 obtained from the survey's 268 topsoil samples (0–5 cm depth; 1 sample per km2). The simultaneous provenancing approach is underpinned by (i) the calculation of Spearman's correlation coefficients (rS) between an evidentiary sample and all the samples in the database for all variables generated by each analytical method; and (ii) the preparation of an interpolated raster grid of rS for each evidentiary sample and method resulting in a series of provenance rasters (“heat maps”). The simultaneous 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 (mineralogy) and XRF (geochemistry) analytical methods offer the most precise and accurate provenance predictions. Maximizing the number of analytes/analytical techniques is advantageous in soil provenancing. Despite acknowledged limitations, it is concluded that the empirical soil provenancing approach can play an important role in forensic and intelligence applications.
AB - Soil is a ubiquitous material at the Earth's surface with potential to be a useful evidence class in forensic and intelligence applications. 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 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 obtained from the survey's 268 topsoil samples (0–5 cm depth; 1 sample per km2). The simultaneous provenancing approach is underpinned by (i) the calculation of Spearman's correlation coefficients (rS) between an evidentiary sample and all the samples in the database for all variables generated by each analytical method; and (ii) the preparation of an interpolated raster grid of rS for each evidentiary sample and method resulting in a series of provenance rasters (“heat maps”). The simultaneous 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 (mineralogy) and XRF (geochemistry) analytical methods offer the most precise and accurate provenance predictions. Maximizing the number of analytes/analytical techniques is advantageous in soil provenancing. Despite acknowledged limitations, it is concluded that the empirical soil provenancing approach can play an important role in forensic and intelligence applications.
KW - geochemical mapping
KW - geographic information system (GIS)
KW - performance analysis
KW - soil forensics
KW - soil properties
KW - Spearman's correlation coefficients (r(S))
KW - Spearman's correlation coefficients (r )
UR - http://www.scopus.com/inward/record.url?scp=85122948387&partnerID=8YFLogxK
U2 - 10.1111/1556-4029.14967
DO - 10.1111/1556-4029.14967
M3 - Article
SN - 0022-1198
VL - 67
SP - 927
EP - 935
JO - Journal of Forensic Sciences
JF - Journal of Forensic Sciences
IS - 3
ER -