Learning Objective: I will be able to explain deposition of particles in water.

Success Criteria: I can explain deposition. I can use the ESRT chart to determine particle size and deposition.

Deposition: The process of dropping or depositing soil and sediments.

ESRT Page 6 Water Velocity With your group determine which particle size will be deposited first. Use the chart to support your answer.

What is Soil?

Soil (dirt) Soil includes loose weathered rock, and organic material in which plant roots can grow

Soil Composition Use this pie chart to answer the questions in your notes.

Soil Composition What do the arrows mean?

Where soil forms Residual soil Transported soil The parent rock is the bedrock beneath the soil (the soil has not moved) Transported soil Soil forms from parent material left by winds, rivers, glaciers, or soil that was moved from its original location. This soil has been transported by erosion and deposition

Factors that affect Soil Composition Parent material: What bedrock is it from? Time: How long has it had to decompose? Plants and animals: How have roots and animals helped break up the rocks? Were there acid producing mosses that help break down the rocks (chemical weathering)? Topography: What is the shape of the landscape? Climate: Is it warm & wet? Were there glaciers present? Was there acid rain?

Soil Profile Cross section of soil layers revealing all soil horizons

Soil Horizon A soil layer with physical and chemical properties that are different from adjacent layers O Horizon= organic material (humus) A Horizon = topsoil B Horizon = subsoil C Horizon = partially weathered parent material

Idealized Soil Profile Humus: Dark organic matter in soil that is rich in nutrients.

Leaching: The removal of nutrients or toxins in soil as water passes through the layers.

Soil Texture The size of soil particles

Particle size ranges for sand, silt and clay  Type of Mineral Particle   Size Range  Sand  2.0 - 0.06 millimeters  Silt  0.06 - 0.002 millimeters  Clay  less than 0.002 millimeters Large/ Coarse Medium Small/ Fine

erosion EROSION

Weathering

Deposition

Sedimentation to “settle”