But first, a time-honored hazing ritual.


An important consequence of the factors we just listed is that in some regions, weathering products hang around and continue to interact with weathering agents and parent material. The result is soil. Terms:

In the real world, soil profiles are influenced and constrained by their environments.

Soil depth varies with:

Soil types - Soil scientists have a complex soil taxonomy. For us, three major types will suffice:

From Kansas Geological Survey - Sequence Stratigraphic Framework of Incised Valley Systems - W. Lynn Watney


A soil requires the constant input of organic material, so it can be "killed" if it is deprived of this. Climate change and burial by sediments can both kill soils. Buried ancient soils are called paleosols. These can be used to reconstruct ancient environments. Laterite paleosols can be commercial sources of aluminum. The study of paleosols is paleopedology.

Identification: Ancient paleosols typically show:

Categories of sedimentary rocks - a review:

As a first level of interpretation we assign rocks to categories based in part on conclusions about how its material was transported. Sediments and sedimentary rocks are classified into three groups based on the types of particles they contain. These groups include:

Stylolites - US National Air and Space Museum


We can also interpret the history of changes that the sediment has undergone since deposition. Loose sediments are transformed into rock, that is they are lithified, by compaction, recrystallization, and cementation. Together, these changes are commonly referred to as diagenesis. The concept also encompasses the changes that sediments undergo after lithification has happened, including mineral replacement and dissolution (right).

Sedimentary depositional environments:

Depositional environments include a set of physical, chemical, and biological processes, acting at a certain time, place, and intensity, preserving recognizable set of geometric and physical attributes. These commonly correspond to some geomorphic entity (e.g., a river) These include:

In a more specific sense, we recognize several distinct major associations of sedimentary rock features associated with depositional environments:
Sedimentary facies: A characteristic association of sedimentary rock features linked to a distinct sedimentary environment. In a given location, one sedimentary facies tends to grade laterally into others. For example, beach rocks from a barrier island may grade into lagoonal rocks which can grade into delta deposits.

Walther's Law:. Don't forget that in conformable deposits (no unconformities), the environments that would be laterally adjacent to one another are also superposed on top of one another.

We can also consider by rock type.