Question

Sand (0.187 inches to 0.003- silt (<0.0029):

a) Sieve Analysis
b) Particle Size Distribution
c) Soil Classification
d) Sedimentation Test

Answer 1

The student is inquiring about soil classification and grain size analysis, commonly applied in geoscience. Sieve analysis determines grain sizes, while a triangular plot classifies the soil sample based on the percentage of sand, silt, and clay.

Step-by-step explanation:

The student’s question pertains to soil classification and grain size analysis techniques often used in geoscience, particularly in the study of sedimentary rocks and soils. These methods include sieve analysis, particle size distribution, and sedimentation tests. The soil classification mentioned often utilizes a triangular plot (ternary plot) for visually representing the proportions of sand, silt, and clay in a soil sample. The process begins with a sieve analysis to determine the grain sizes present in a sample and to calculate the weight percent for each grain size category.

To create the particle size distribution graph, you can use Figure 5.4, where the weight percent data is plotted as a bar graph showing the various grain size fractions. Furthermore, the use of a triangular plot, shown in Figure 0.6, allows geologists to classify sediment types based on the percentages of sand, silt, and clay within the sample. The soil or sediment is then named accordingly using the nomenclature provided in the field subdivisions on the plot.

Steps to Analyze Grain Size:

1. Measure the total weight of the sediment sample.
2. Separate the sediment using sieves into different size fractions.
3. Record the weight of each size fraction and calculate the weight percentage.
4. Plot the weight percentage on a bar graph.
5. Use the triangular plot for soil classification by plotting the proportions of sand, silt, and clay.