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Soils, Minerals, Wood, & Other Vegetative Matter bsapp.com
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Soils, Minerals, Wood, and Other Vegetative Matter. Location Link suspect Trace Evidence bsapp.com
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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
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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
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Components in soil
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Breakdown of soil Clay Sand Silt Loam is a mixture of all parts 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.
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Soil Textures Soil Particles Gravel:larger than 2mm; feels coarse Sand:2 - 0.05mm; feels gritty Silt:0.05 - 0.002mm; feels like flour Clay:smaller than 0.002; feels sticky when wet
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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/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/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/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/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/il_soil.pdf ftp://ftp-fc.sc.egov.usda.gov/NSSC/StateSoil_Profiles/ak_soil.pdf ftp://ftp-fc.sc.egov.usda.gov/NSSC/StateSoil_Profiles/ak_soil.pdf Original site: http://soils.usda.gov/gallery/state_soils/
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12 Orders/Categories of Soil
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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
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Keep in mind… Dirt changes shade and color at different moisture levels Dried dirt may clot bsapp.com
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Gross Examination 1. Color 2. Texture 3. Shapes 4. Foreign Objects bsapp.com
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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
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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?
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Florescence Bathroom tile as viewed with the visible light spectrum Now: viewed using UV light (black light)
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Materials that are fluorescent: Semen Blood Urine Vitamins Antifreeze Chlorophyll Minerals in rocks Scorpion exoskeleton Panties stained with semen Blood appears dark under UV light because it will absorb all of the spectrum Urine in toilet is glowing BAD kitty! Antifreeze under black light -helps to detect leaks -used to recreate crash scenes Animals with UV light vision will be attracted to the “glowing blue” of a ripened banana Hope Diamond Light spectrum Hope Diamond UV Light
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bsapp.com
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The clothes of this female look normal. Any chemicals? bsapp.com
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A UV-Light may also be used to find trace evidence on a body bsapp.com
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Microscopic Observation Color Texture Shapes Foreign Objects bsapp.com
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Place a thin layer of dirt on a slide bsapp.com
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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
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Place a second slide on top of the sample bsapp.com
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Naked Eye bsapp.com
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Microscopic x10 bsapp.com
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Microscopic x40 (Cotton Fiber) bsapp.com
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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
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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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