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Sedimentary features Sedimentary Rocks are mainly influenced by surface processes. Therefore they give us powerful clues to all the processes that affected their formation, from the original rock that was weathered, all the way to what they are and look like today. Thus they enable us to reconstruct the history of an area. In addition, they contain fossils (=any evidence of past life). Fossils tell us about the environment in which they lived. They (fossils) are also documents of evolution and time markers.

Aside from composition, sedimentary rocks often show features that give valuable information about the environment in which they formed. Some of the more important features are associated with layering, bedding or stratification.
Types of bedding
        Cross bedding
                 fluviatile
                 aeolian
         graded bedding
         massive bedding
         warves
Bedding surface features
         Ripple marks
                 current and
                 oscillating
         Mud cracks
         Burrows and tracks
         Rain drops etc.
Fossils

Sedimentary rocks and plate tectonics

In areas where major accumulation takes place, along the margins of continents, sedimentary layers will undergo progressive burial. Most sedimentary rocks are marine in origin and contain sea water which was trapped between the sedimentary particles during deposition. In passive margins, as the underlying crust deforms under the weight of accumulated sediments, these sediments are buried deeper, and pressures and temperatures increase. Sediments may also be affected by deformation and igneous activity, especially along active continental margins.