<p>Name:______Date:______Period: 1 2 3 4 5 6 PARTICLE SIZE DISTRIBUTION Background: When rock goes through weathering we saw that mass was lost. Pieces of rock that come off during weathering will settle to form soil. Different types of weathering produce different types of soil.  Mechanical weathering tends to yield larger particles : o small pebbles o sand.  Chemical weathering tends to yield smaller particles: o clay o silt In this activity, you will determine the composition of a locally collected soil sample. Soil consists of 3 main particle sizes:  clay,  silt  sand You will analyze the amount of each of the 3 main particle sizes in the sample and then determine the soil type. After the initial set up, the sample must settle overnight for interpretation on the next day.</p><p>Prelab Questions: 1. During the last two activities you learned about mechanical weathering and chemical weathering. How are they similar? ______2. How are mechanical weathering and chemical weathering different? ______Read the procedure and answer the following questions: 3. What are the 3 types of soils will we be studying? a. ______b. ______c. ______4. What do you need to do to the clay and local soil sample before putting them in the jar? ______5. How long do you shake the jar? ______6. What is the purpose of the drop of detergent? ______Day 1: Materials Grease Pencil A bowl of Collected Soil 3 plastic jars with lids A large beaker filled with water 4 A bowl of Sand Bottle of Detergent A bowl of Clay</p><p>Procedure 1. With the china marker, label 3 jars (one jar for each soil type):  Sand  Clay  Local Soil Sample 2. Break up any clumps in the clay and collected soil samples. 3. Fill each jar halfway with the soil type that matches the label. 4. Add water from the beaker to just below the rim of each jar. 5. Tightly secure the lid of each jar. 6. Shake each jar for 1 minute each, one jar at a time. 7. Open the lids 8. Put 1 drop of detergent into each jar. (This will help settle the particles.) 9. Tighten the lids securely. 10. Place jars in designated area to settle overnight.</p><p>Day 2: Materials 3 Labeled plastic jars with lids and soil samples Ruler White paper Calculator Pen or pencil China Marker</p><p>Procedure 1. Place white paper behind each of the jars. 2. Look at the layers in each. 3. In the observations section, draw each of the jars with their layers.  Show Ms. Grant to earn your stamp! 4. Compare your collected soil sample to the Sand and Clay samples. Identify what each layer of your sample is made of: sand, clay, or something else.  If it looks like either sand or clay, it is! 5. With the China Marker, label each of the layers on the jar. **Note: The layer that forms between the sand and clay layers is the silt layer. The dark layer at the top is humus, decaying organic material that makes up part of the topsoil. 6. Label the layers in your drawings in the observation section. 7. Measure in cm how high the soil is in your Collected Soil Sample. </p><p> Total soil depth: ______</p><p>8. Measure how high each layer is in the Collected Soil Sample.</p><p> Clay layer depth: ______</p><p> Silt layer depth: ______</p><p> Sand layer depth: ______</p><p>Observations DRAWINGS of Jars after Settling, including: *BE SURE TO GET THESE STAMPED!!!!!  Jar + Lid  Each type of particle in that sample, labeled.  The size of each layer, in cm. CLAY</p><p>SILT</p><p>SAND</p><p>Data Calcualtion 9. Take the “Total Soil Depth” in cm from question #7, and record it in each data table in the column labeled “Total Depth.” TOTAL DEPTH column is after the ÷ sign. 10. Take the “Clay Layer Depth” from question # 8, and record it in the correct table below (below where it says depth of clay). This is the column before the ÷ sign. 11. Take the “Silt Layer Depth” from question # 8, and record it in the correct table below (below where it says depth of silt). This is the column before the ÷ sign. 12. Take the “Sand Layer Depth” from question # 8, and record it in the correct table below (below where it says depth of sand). This is the column before the ÷ sign. 13. Ignore the top most layer (humus). 14. Calculate the particle size distribution of the sample by doing the following: </p><p> Divide (÷) the number in the layer column by the number in the total depth column.  Multiply by 100.  Record the result in your data table as % of each type.</p><p>% of Clay Depth of Clay Layer ÷ Total Depth x 100 = % Clay Collected Sample</p><p>% of Silt Depth of Silt Layer ÷ Total Depth x 100 = % Silt Collected Sample</p><p>% of Sand Depth of Sand Layer ÷ Total Depth x 100 = % Sand Collected Sample Name:______Date:______Period: 1 2 3 4 5 6 PARTICLE SIZE DISTRIBUTION </p><p>DATA ANALYSIS Use the chart to figure out what type of soil your collected sample is.</p><p>How to use the chart:</p><p>Each corner of the triangle represents 100% of one of the 3 classes of soil: sand, silt, or clay.</p><p>Loam is a mixture of all three soil types.</p><p>1. Your % Silt: ______(from your data calculations) </p><p>Find the % silt of your sample on the chart above, and put a mark there.</p><p>2. Your % Sand: ______(from your data calculations)</p><p>Find the % sand of your sample on the chart above, and put a mark there.</p><p>3. Your % Clay: ______(from your data calculations)</p><p>Find the % clay of your sample on the chart above, and put a mark there.</p><p>4. Draw along the diagonal lines, starting at each of the points, until the lines cross.</p><p>5. Where they intersect is the soil type of your sample.</p><p>6. If it lands on the border of two types, choose the type that takes up the most space on the chart.</p><p>Clay: 60-100% clay 0-40% silt No sand Sandy Clay: 35-55% clay no silt 60-85% sand Sandy Clay Loam: 20-35% clay 60-70silt 60-90% sand Clay Loam: 30-40% clay 60-73 %silt 30-75% sand Silt: No clay 87-100% silt 0-20% sand Silty Clay: 60-40% clay 60-40% silt No sand Silty Clay Loam: 60-40% clay 60-73% silt 12-35% sand Silt Loam: 0-30% clay 72-88% silt 20-50% sand Sand: 0-10% clay No Silt 90-100 % sand Sandy Loam: 15-20% clay 80-93% Silt 70-50 % sand Loamy Sand: 10-17% clay 80-90% Silt 70-88 % sand Loam: Equal parts of clay, silt and sand</p><p>Questions: 1. What type of soil is the Local Soil Sample? ______</p><p>2. After observing the control jars, which type of particle (silt, clay or sand) do </p><p> you think is smaller and lighter? ______</p><p>Explain.______</p><p>______</p><p>______</p><p>3. Which particle type is larger and heavier? ______</p><p>Explain. ______</p><p>______</p><p>______</p><p>4. Which particle was the most abundant?______</p><p>5. Explain one way these different-sized particles are formed.______</p><p>______</p><p>______</p><p>6. Why is there mostly sand at the beach and mostly clay inland?______</p><p>______</p><p>______</p>