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Soils, Minerals, Wood, & Other Vegetative Matter

Soils, Minerals, Wood, & Other Vegetative Matter. bsapp.com. Soils, Minerals, Wood, and Other Vegetative Matter. Location Link suspect Trace Evidence. bsapp.com. Soil. Any material, both natural and artificial, that lies on or near the Earth's surface

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Soils, Minerals, Wood, & Other Vegetative Matter

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  1. Soils, Minerals, Wood, & Other Vegetative Matter bsapp.com

  2. Soils, Minerals, Wood, and Other Vegetative Matter. • Location • Link suspect • Trace Evidence bsapp.com

  3. Soil • Any material, both natural and artificial, that lies on or near the Earth's surface • Most of this evidence is only useful as support or lead generating bsapp.com

  4. Examination of Soil Throughout the examination of soil an observer must: • Look for trace evidence • Compare the physical and chemical properties of each sample to a control sample bsapp.com

  5. Components in soil

  6. What's your type?Squeeze some soil between your fingers. Is it crumbly? Sticky? A soil's texture depends on the size of its particles. And living things depend on the right texture to thrive in the soil. Breakdown of soil • Clay • Sand • Silt Loam is a mixture of all parts

  7. Soil Textures Soil Particles Gravel:larger than 2mm; feels coarseSand:2 - 0.05mm; feels grittySilt:0.05 - 0.002mm; feels like flourClay:smaller than 0.002; feels sticky when wet

  8. Let’s look at certain areas • ftp://ftp-fc.sc.egov.usda.gov/NSSC/StateSoil_Profiles/tx_soil.pdf • ftp://ftp-fc.sc.egov.usda.gov/NSSC/StateSoil_Profiles/la_soil.pdf • ftp://ftp-fc.sc.egov.usda.gov/NSSC/StateSoil_Profiles/ok_soil.pdf • ftp://ftp-fc.sc.egov.usda.gov/NSSC/StateSoil_Profiles/fl_soil.pdf • ftp://ftp-fc.sc.egov.usda.gov/NSSC/StateSoil_Profiles/il_soil.pdf • ftp://ftp-fc.sc.egov.usda.gov/NSSC/StateSoil_Profiles/ak_soil.pdf Original site: http://soils.usda.gov/gallery/state_soils/

  9. 12 Orders/Categories of Soil

  10. Matching Soil Samples Two samples are considered to be the same if and only if they match on each and every level of the following tests bsapp.com

  11. Keep in mind… • Dirt changes shade and color at different moisture levels • Dried dirt may clot bsapp.com

  12. Gross Examination • Color • Texture • Shapes • Foreign Objects bsapp.com

  13. UV-Observations • Note the shape, size, number, and identity (if possible) of any material that fluoresces • Compare samples to known dirt from an area bsapp.com

  14. Review: Electromagnetic Spectrum A phosphor material converts the energy in the UV radiation from a black light into visible light. UVA = black light UVB= harmful rays (skin cancer) FACT: a persons skin will tan with AVA and sunburn with UVB… so what times of the day does the sun emit UVB?

  15. Florescence Bathroom tile as viewed with the visible light spectrum Now: viewed using UV light (black light)

  16. Materials that are fluorescent: Hope Diamond UV Light Urine in toilet is glowing • Semen • Blood • Urine • Vitamins • Antifreeze • Chlorophyll • Minerals in rocks • Scorpion exoskeleton Blood appears dark under UV light because it will absorb all of the spectrum Hope Diamond Light spectrum Panties stained with semen Antifreeze under black light -helps to detect leaks -used to recreate crash scenes BAD kitty! Animals with UV light vision will be attracted to the “glowing blue” of a ripened banana

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  19. The clothes of this female look normal. Any chemicals? bsapp.com

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  26. A UV-Light may also be used to find trace evidence on a body bsapp.com

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  28. Microscopic Observation • Color • Texture • Shapes • Foreign Objects bsapp.com

  29. Place a thin layer of dirt on a slide bsapp.com

  30. Place only a small amount of sample on the slide at a time. Be sure the dirt is placed only in the center of the slide so as not to allow it to fall in the microscope. WARNING bsapp.com

  31. Place a second slide on top of the sample bsapp.com

  32. Naked Eye bsapp.com

  33. Microscopic x10 bsapp.com

  34. Microscopic x40 (Cotton Fiber) bsapp.com

  35. Final Comparison • Any and all foreign objects found should be investigated separately • If all previous comparisons are similar between two samples they likely originate from the same area • As final comparison density gradient columns may be utilized bsapp.com

  36. Density Gradient Tubes • Assemble two identical density columns with varying levels of liquids in them • Drop equal amounts of soil samples (a control and unknown) in the columns • Allow the samples to disperse throughout the columns for comparison • If the two samples are of the same origin, then they will produce nearly identical gradient tubes bsapp.com

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