Soils

« 
Previous image
|
|
Next image
 »

Soils

A sequence of samples pulled up in a coring device that takes very small samples -- 1.7 cm in diameter.

A) This is the "topsoil". It is dark in color and has a crumb structure. Roots are abundant.

AB) This layer still has mainly a crumb structure, but is a bit lighter and has a few less roots.

BA) This layer shows some dark areas of the above layers, but has fewer roots and is mainly composed of an accumulation of yellow clay.

Bt) This layer is dominated by reddish-yellow clay, which has accumulated in "films". These films are thick and dominate the sample. This clay has moved down from the surface soil, and has been deposited here. This type of clay provides strong evidence of soil formation processes.

2Ab) Here we have a second topsoil, which has been buried. It has similar structure to the topsoil above. While it is not as dark, it is still brown rather than red or yellow in color.

2Bt) This second layer of clay accumulation shows similar films and color to the layer above -- the color is even more pronounced. This layer suggests that the buried soil was stable for a long period.

2C) At the very bottom of the profile, the corer brought up rock fragments (reddish) in a matrix of clay. This represents soil forming from the rapid weathering of the underlying rock.