• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Soil Evidence
 

Soil Evidence

on

  • 3,955 views

 

Statistics

Views

Total Views
3,955
Views on SlideShare
3,955
Embed Views
0

Actions

Likes
1
Downloads
0
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Soil Evidence Soil Evidence Presentation Transcript

    • TRACE EVIDENCE SOIL ANALYSIS
    • Soil
      • soil or dried mud adhering to suspect’s clothing or shoes or to an automobile may link a suspect or object to the crime scene when compared to the soil there
      • soil analysis without a crime scene can also be helpful in finding the place where the crime was committed
    • Soil
      • analysis must be made with soil dried under identical lab conditions
      • analysts look for
        • physical characteristics
        • chemical characteristics
    • Soil
      • physical characteristics
        • microscopic examination –
          • reveals presence of plant and animal materials
          • any artificial debris
          • helps characterize minerals and rocks in earth materials
    • Soil
      • physical characteristics
        • color – 1,100 soil colors
        • soil types
        • magnetic particles
        • fluorescence
    • Soil
      • chemical characterisitics
        • pH
        • nitrates, phosphates, potassium
        • carbonates, iron, chloride, copper
    • Soil
      • to determine common origin of soil samples one must consider…
        • number of comparative points
        • frequency of occurrence
    • Soil
      • geology training helpful
      • 2,200 minerals exists, only ~20 are common
      • rocks are combinations of minerals, characterized by
        • mineral content
        • grain size – using sieve set
    • Soil – Mineral Properties
      • color
        • useful but limited
        • many minerals appear in a variety of colors
        • many are white or colorless
      • size
        • simple labels: coarse, medium, fine grains
        • use of sieve set to further describe
    • Soil – Mineral Properties
      • texture
        • describes crystal’s outward appearance
        • generally referred to as the “habit” of a crystal
    • Soil – Mineral Properties
      • texture – habits
        • dendritic – has a plant like shape
        • as in copper
    • Soil – Mineral Properties
      • texture – habits
        • bladed – appears as layers that look like the blades of knives
        • as in actinolite
    • Soil – Mineral Properties
      • texture – habits
        • acicular – forms as pointy, needle-like masses, or radiating
        • as in scolecite
    • Soil – Mineral Properties
      • texture – habits
        • massive – has no definite shape
        • as in limonite
    • Soil – Mineral Properties
      • texture – habits
        • prismatic – looks like many prisms fused together (as in barite)
        • or a uniform cross section (as in beryl)
    • Soil – Mineral Properties
      • texture – habits
        • reniform – looks like a jumble of rounded masses
        • as in hemitite
    • Soil – Mineral Properties
      • luster
        • describes the way light is reflected off of the mineral’s surface
        • type and intensity vary according to
          • mineral surface
          • amount of light absorbed
    • Soil – Mineral Properties
      • luster
        • vitreous
        • glass-like
    • Soil – Mineral Properties
      • luster
        • greasy
        • milky
    • Soil – Mineral Properties
      • luster
        • silky
        • satiny
    • Soil – Mineral Properties
      • luster
        • pearly
    • Soil – Mineral Properties
      • luster
        • metallic
    • Soil – Mineral Properties
      • luster
        • dull or earthy