GEOG 3360 Midterm Take-Up
1. Given the table in Part 1, the task is to conduct an analysis of these three soil profiles. The source
parent material is alluvium(which is loose unconsolidated soil that has been eroded, reshaped by water,
and redeposited in a non-marine setting, and is made up of a variety of materials.) The lowermost
horizon is fresh parent material, granitic. You are asked to discuss the clay mineral distributions.
a) Soil A--right away, we notice that the smectite concentration is deep down in B horizon, and kaolinite
increases going down the profile. There is also increasing illite from B horizon downwards.
Metahalloysite is detrital. However, these trends are pretty detrital and fluctuate. This means that clay
forming genesis is not very significant. There is no pedogenic trend.
Soil B--Definite pedogenic trend for illite. Lots of illite and smectite, nothing else. What does this mean?
Soil C-A lot of kaolinite and metahalloysite. I would say this is the youngest soil because kaolinite tends
to be high in younger soils.
b) The parent material is definitely uniform because we notice illite as the only thing present in the
parent material in all three of these soils. The concentration of illite in the lowermost horizon is exactly
the same, and it is fairly uniform. Lithological uniformity occurs w