Lab 6

Can we have Ct and Af horizons?

Good question. There is no such thing as Ct horizon, since "t" is only associated with the B horizon (and no there is no At horizon either). The "t" implies enrichment (accumulation) of illuvial clay particles that have been moved from a horizon of eluviation, which then translates into a higher clay content in the illuviated (i.e. Bt) horizon than eluviated (Ae) horizon above it. Generally, in soils there isn't enough water (moving through its profile) to do the same translocation (movement) of clay particles from B to C horizon. Hence, there is no Ct

There is no Af horizon either. Accumulation of Al and Fe oxides (released due to weathering of secondary & primary minerals), as designated by "f", occurs in the B horizon.

Hi Maja, what is the designation of pure sandy horizon? I chose Ae to represent sandy horizon, but I am not sure.

There is no designation for a pure sandy horizon. Sand was included into the question (2a) to indicate that this is a mineral horizon. More hints about this question can be found in my answer to another question as shown below

Hi, Maja, can I say the horizon with both A and B horizon properties is AB for Q 2d? And for 2a, should I count it as LFH or Ah?

Re 2b - All so called transitional horizons have properties that integrate 2 horizons above and below it.

In question 2a it is specified that horizon is sandy; hence, that is a mineral horizon and as such it cannot be LFH since those are organic horizon. Ah horizon has a soil formation process (accumulation of organic matter occurring in it, as signified by the letter "h"). Consequently, Ah is not the correct answer for question 2a. You have to think of a mineral horizon in which there is no soil development or no soil formation process.......

Hey Maja, for 2 a) could E be a good answer? It is a mineral horizon used in the united states, and I don't think any soil development occurs on that horizon given that mostly quartz is left behind. Or should we only consider A, B, and C as the mineral horizons.

E (as used in the US soil classification system) is the same as Ae (in Canadian system). But regardless of the system, E (or Ae) is the horizon characterized by the soil process of eluviation (or leaching out of either clay particles and/or organic matter) indicating that soil development is taking place. Hence, E (or Ae) cannot be the answer for question 2a. The answer is among A, B and C horizons........