Jambo! Do Now: Do Now: Take out HW and Thank you notes Take out HW and Thank you notes Agenda: Agenda: Notes quiz Notes quiz Intro to Soil Intro to Soil HW: HW: Soil Handout online Soil Handout online

What Is Soil? Mixture of organic and inorganic material Mixture of organic and inorganic material May range from 100% inorganic (sand) to nearly 100% organic (peat) May range from 100% inorganic (sand) to nearly 100% organic (peat) Inorganic part is minerals Inorganic part is minerals Organic part is decayed plant and animal material and is sometimes called humus Organic part is decayed plant and animal material and is sometimes called humus

Soil primarily made of: primarily made of: weathered rock weathered rock air air H 2 O H 2 O bacteria bacteria Humus Humus soil formation process is what makes soils unique soil formation process is what makes soils unique influenced by temperature, rainfall, chemicals and minerals present influenced by temperature, rainfall, chemicals and minerals present

Forensic Significance of Soil Soil is class evidence - cannot be individualized to a particular location Soil is class evidence - cannot be individualized to a particular location Soils can be easily transported Soils can be easily transported Soils within a few meters horizontally or vertically differ Soils within a few meters horizontally or vertically differ

Soil Composition Three main grain sizes Three main grain sizes Sand  largest Sand  largest Silt Silt Clay  smallest Clay  smallest Three sub categories of soil Three sub categories of soil Loam  sand, silt, clay Loam  sand, silt, clay Peat  more than 20% decaying material Peat  more than 20% decaying material Chalk  Alkaline, solid but soft rock Chalk  Alkaline, solid but soft rock

Soil Type Comparison

Horizons in a Soil Sample

Horizons O Horizon O Horizon Humus- decaying organic material Humus- decaying organic material A Horizon A Horizon “top soil”  soil is dark in color “top soil”  soil is dark in color mixture of Humus and mineral particles mixture of Humus and mineral particles This is where seeds sprout and plant roots grow This is where seeds sprout and plant roots grow E Horizon E Horizon Light in color  Made of sand and silt Light in color  Made of sand and silt H 2 O drips through this layer and carries away most of the minerals and clay originally present H 2 O drips through this layer and carries away most of the minerals and clay originally present

Horizons cont’d B Horizon B Horizon “subsoil” “subsoil” contains clay and mineral deposits that have leached from layers above contains clay and mineral deposits that have leached from layers above C Horizon C Horizon layer is made up of partially broken rock layer is made up of partially broken rock no humus or plant roots no humus or plant roots R or D Horizon R or D Horizon soild rock soild rock

Chemistry of Soil Nutrients: NPK Nutrients: NPK Nitrogen Nitrogen promotes chlorophyll production promotes chlorophyll production needs a pH >5.5 to be dissolved in H 2 O and contained within the soil needs a pH >5.5 to be dissolved in H 2 O and contained within the soil Phosphorus Phosphorus necessary for root development and increases flowering ability and size necessary for root development and increases flowering ability and size needs a pH between needs a pH between Potassium Potassium guards against disease and aids in draught protection and cold tolerance guards against disease and aids in draught protection and cold tolerance

pH Review NPK dissolves more easily in slightly acidic or alkaline environment Rainfall, pollution, acid rain, and fertilizer can all affect pH

Results of nutrient Deficiencies

Sand Formed by Weathering Formed by Weathering action of wind and water on rocks action of wind and water on rocks collisions break rock into smaller and smaller pieces collisions break rock into smaller and smaller pieces grains are usually grains are usually 0.05mm to 2mm in diameter 0.05mm to 2mm in diameter Shape is rounded or angular Shape is rounded or angular Crystal- if sand only contains one type of mineral Crystal- if sand only contains one type of mineral Fragment- if the grain consists of 2 or more minerals Fragment- if the grain consists of 2 or more minerals

Sand Rounding Rounding can take millions of years to complete can take millions of years to complete Immature or Young Immature or Young contains a large portion of clay contains a large portion of clay grains have a high % of fragments grains have a high % of fragments Found in bottom of bays, lagoons, swamps or river plains Found in bottom of bays, lagoons, swamps or river plains Mature or Old Mature or Old No clay and fewer fragmented edges No clay and fewer fragmented edges Found in beaches and desert dunes Found in beaches and desert dunes lots of H 2 O and weathering lots of H 2 O and weathering

Sand Composition

Continental contains quartz, micas, feldspar, hornblede, magnetite contains quartz, micas, feldspar, hornblede, magnetite Feldspar Feldspar if present then the sand probably came from a temperate, polar climate, or a high latitude if present then the sand probably came from a temperate, polar climate, or a high latitude in warm, tropical climates it weathers away quickly in warm, tropical climates it weathers away quickly Quartz Quartz high % means that the sand is very old high % means that the sand is very old weathers very slowly weathers very slowly

Mineral Components of Sand

Volcanic usually dark in color because of black basalt or green olivine usually dark in color because of black basalt or green olivine From mid-ocean volcanoes, hot-spot volcanoes (Hawaii) From mid-ocean volcanoes, hot-spot volcanoes (Hawaii) sometimes contains volcanic cinders or other volcanic debris sometimes contains volcanic cinders or other volcanic debris very young and has little to no quartz very young and has little to no quartz

Jambo Do Now: Do Now: Take out your HW and compare what you found with your lab bench. Take out your HW and compare what you found with your lab bench. Describe the soil around your houses. What kinds of plants are growing around your house? What do you think forensic scientists would find unique about the soil around your house? How do you think they could determine that soil came from your house and not a neighbor’s house? Agenda: Soil Activity Agenda: Soil Activity HW: Read Coors Case and Answer Q’s Due 11/8 HW: Read Coors Case and Answer Q’s Due 11/8

Soil Observation Activity Visually examine the soil on each plate and take notes about each sample. Write down which samples you believe came from the same location. Explain your conclusions Visually examine the soil on each plate and take notes about each sample. Write down which samples you believe came from the same location. Explain your conclusions

Skeletal made from marine organisms: made from marine organisms: microogranisms microogranisms shells shells corals corals younger type of sand younger type of sand Coral is found only in tropical regions Coral is found only in tropical regions Large amounts of CaCO 3  creates bubbles with the addition of acid Large amounts of CaCO 3  creates bubbles with the addition of acid

Precipitate contains dissolved minerals contains dissolved minerals when H 2 O evaporates minerals come out of solution and form crystals when H 2 O evaporates minerals come out of solution and form crystals CaCO 3 can precipitate out of sea water forming a coat of hard particles that resemble an onion CaCO 3 can precipitate out of sea water forming a coat of hard particles that resemble an onion eventually form small, round particles  oolites eventually form small, round particles  oolites

Soil Collection 1.collect all samples as soon as possible 2.collect at surface baseline and samples that appear different or out of place from the rest of the environment 3.collect at least 4 tbsp of material from several locations at the scene. (Plastic Vials) 4.sketch the crime scene and note where the samples were obtained 5.be careful not to remove soil stuck to shoes, clothing, or tools found at the crime scene. Package these items separately in appropriate containers (Paper Bags) 6.carefully remove soil from vehicles and package the soil samples separately 7.Document all samples by taking photographs, drawing sketches, and labeling the evidence collection containers 8.Collect additional soil samples from the four compass point (N,S,E,W) within a few feet of the crime scene. Collect another set feet from the crime scene

Soil Examination compare characteristics of the soil samples from suspect or crime scene to those from a known location compare characteristics of the soil samples from suspect or crime scene to those from a known location layers of soil or mud from shoes or wheels can show that a suspect was present at a series of locations layers of soil or mud from shoes or wheels can show that a suspect was present at a series of locations compare size, shape, color by looking macroscopically compare size, shape, color by looking macroscopically soil type, amount of organic material, particle size soil type, amount of organic material, particle size Can be identified and compared by Can be identified and compared by density density moisture content moisture content chemical testing for mineral content chemical testing for mineral content X-ray Diffraction X-ray Diffraction

To identify the minerals in rock and soil samples, the Curiosity will lean heavily on X-ray diffraction technology To identify the minerals in rock and soil samples, the Curiosity will lean heavily on X-ray diffraction technology X-ray diffraction is the most reliable way to identify minerals, but this is the first time it will be used on a mission to Mars. X-ray diffraction is the most reliable way to identify minerals, but this is the first time it will be used on a mission to Mars. When samples are collected, an X-ray beam will be focused at it, and the sample will scatter the X-rays in different directions When samples are collected, an X-ray beam will be focused at it, and the sample will scatter the X-rays in different directions

each mineral has a trademark diffraction pattern, allowing scientists to identify what mineral they're looking at NASA’s Curiosity rover has completed the first-ever detailed X-ray analysis of Martian sand, determining that it contains minerals similar to volcanic soil found at places like the Mauna Kea shield volcano in Hawaii