Module 06 Part 1 Weathering and Soil Lab

Name: _________________ GOL 105: Weathering and Soil Lab Objective: The objective of this exercise is to help familiarize you with the basic soil profile, the processes responsible for creating each of the horizons within the profile, and the general characteristics of weathering of geologic material . Introduction: This exercise will utilize the information contained in Chapter 6 (Weathering and Soil) in your textbook. All work can either be completed directly on this document (save it to your hard drive with a file name that includes your last name, then complete the exercise, save your copy, and then submit it via Blackboard). Another option is to print it, draw/write on the paper, then scan or photograph it to make digital files capable of being submitted via Blackboard. Note that you will have to draw on several photos, either with pen/pencil or digitally. Directions: 1. Read Chapter 6 (Weathering and Soil) in your textbook. 2. Complete Table 1 . Identify the soil horizons in a typical soil profile. Fill in the name of the soil horizons in the left hand column of the figure, and give a brief description of the content and processes in each of the horizons in the left hand column. (10 pts) 3. Complete Table 2 . Identify the five (5) most important factors affecting the development of a soil at any given location. List each factor separately in the left side column of the table, and then briefly discuss a few specifics on how this may affect the development of a soil profile. Which horizons will be most affected by each factor? (10 pts) 4. Complete Figures 3, 4, and 5 . Try your hand at identifying the various soil horizons in each of these two figures. Draw the boundaries on the photo , and clearly label each horizon with the corresponding letter (O, A, E, B, etc .). Labels may be placed in the white space next to the photo for clarity. (10 pts) Revised: December 2018 Page 1 of 6

Name: _________________ Figure 1: A Typical Soil Profile Name of soil horizon Description ____ O ___ Horizon (Topsoil) ● Mostly organic material, especially still-recognizable plant litter ● Lots of microscopic life, which contributes oxygen, carbon dioxide, and organic acids ____ A ___ Horizon (Topsoil) ● Mostly mineral matter ● High biological activity ● Up to 30% humus (partly decomposed organic matter) ____ E ___ Horizon (Zone of Leaching) ● Light colored ● Little organic material ● As water filters down through here, finer particles are carried away ● Soluble inorganic soil components are carried deeper by the water ____ B ___ Horizon (Subsoil ; Zone of Accumulation) ● Lots of the material that gets filtered out of E ends up here ● Enhanced water-holding ability due to the collection of fine clay particles ● Can form a very compact, impermeable layer called hardpan ____ C ___ Horizon ● Partially altered parent material ● Parent material is easily identifiable ● Has not yet crossed the threshold separating regolith and soil Bedrock ● Unweathered parent material Revised: December 2018 Page 2 of 6