Soil

what is soil?

• soil makes up the uppermost layer of the earth's crust
• It is composed of both organic and inorganic materials

Physical Properties of Soil

• size
• density
• temperature
• water
• color

chemical properties of soil

• Soil is made up of Oxygen, silicon, aluminum, and iron
• Lots of minerals are present as well

how do forensic scientists define soil

• they analyze naturally occurring rocks and minerals
• they also analyze paint chips, glass, asphalt, cinders and brick fragments
• these link soil to particular locations

HOW ARE SOILS look DIFFERENT THROUGH THE NAKED EYE

• through color and texture

microscopic differentiation

• with low powered microscopes animal minerals and debris are visible
• with high power microscopes can see minerals and rocks
• particle size and shape can be different

chemical property distinctions

• use X-ray diffraction to compare compositions
• this pulverizes the soil which produces patterns

what are minerals and why are they important

• a minerals is a naturally occurring crystal
• minerals are classified by theirs color, shape, density, and refractive index
• they give geologists more points to compare

density gradient tubes

• each tube is filled with two layers of different liquid
• the soil particles sink to the layer of the tube that has an equal density

SOIL MATCHED AND HOW the soil is taken

• the chance of matching soil samples is dependent on the area
• only need about a table spoon or two of soil in order to run tests
• are taken from alibi location, suspects car, and suspects clothes