日本地球惑星科学連合2022年大会

講演情報

[E] 口頭発表

セッション記号 M (領域外・複数領域) » M-GI 地球科学一般・情報地球科学

[M-GI31] 法地質学への招待

2022年5月25日(水) 09:00 〜 10:30 301B (幕張メッセ国際会議場)

コンビーナ:Bradak Balazs(神戸大学)、コンビーナ:川村 紀子(海上保安大学校 基礎教育講座)、杉田 律子(科学警察研究所)、コンビーナ:Gomez Christopher A(神戸大学 海事科学部 海域火山リスク科学研究室)、座長:杉田 律子(科学警察研究所)、川村 紀子(海上保安大学校 基礎教育講座)、Gomez Christopher(神戸大学 海事科学部 海域火山リスク科学研究室)、Balazs Bradak(神戸大学)


09:05 〜 09:30

[MGI31-01] Role and importance of geological and soil reference data in forensic geology reports of examination

★Invited Papers

*Libby A Stern1、Ian Saginor1、Jodi Blakely Webb1 (1.FBI Laboratory)

キーワード:Forensic, geology, soil, geological maps, soil maps

Examination of geological material as trace evidence in a police investigation often consists of trace soil or sediment attached to an object of interest, such as a shoe, a vehicle or a shovel. The amount of material present is often small, often 100’s of mg, and may be fractionated due to preferential attachment or loss of different particle classes or mineral types. Because of these limitations, the best methods of examination of forensic geological materials are minimally destructive or focus on characterizing individual particles. The more common methods of examination are: optical microscopy for characterization of minerals, lithic fragments, palynomorphs, and other biological particles; color determination; X-ray diffraction; and SEM-EDS.

Two common goals of examination of forensic geological material are 1) COMPARISON: to compare the geological evidence to the soils and geological material at a crime scene to assess if the evidentiary soil could have originated from the crimes scene and 2) PROVENANCE: to examine and interpret the trace geological material for its possible geographic origin to aid the police investigation (e.g. searching for a clandestine burial based on soil on a shovel). The importance of published reference data for provenance examinations is evident to any geologist, but even for comparison examinations publications about the local and regional geology are quite important. The geologist-forensic examiner is presenting their result to a judge or a judge and jury who are unlikely to have sufficient geological knowledge to understand when a mineral assemblage is rare and when it is common, or when it is common in a geographically restricted region. The reference data, to include geological and soil maps, as well as theses, papers and reports, are important for geologist-forensic examiners to provide unbiased context for the importance of their results.

A few examples of how geological and soil reference data have been applied in forensic cases will be presented to include both examinations for soil comparison and soil provenance assessments.