Natural processes like frost heaving, erosion, and the down-slope movement of soils in colder climates (solifluction) can alter the original context in which the artifacts were deposited.
Stratigraphic levels can be horizontal as well as vertical.
Level II (middle): pictures of sherds (broken pieces) of decorated pottery; a mortar and pestle for grinding grain; scattered beads and carved figures; post holes (shown as a regularly patterned darkened areas of soil) for a dwelling; scattered bones of wild game. Ancient Washington: American Indian Cultures of the Potomac Valley.
These artifacts suggest people who are settled, at least part of the time. Washington, DC: George Washington University, 1977. (local study containing cultural sequence of eastern U.
All dating methods have limitations and can be complicated by turbation, or mixing, of layers by human or natural actions.
Multiple dating methods are usually required before dates are accepted.
Or perhaps a burrowing animal tunneled down through a site, causing artifacts buried above to fall to lower levels.
Stratigraphic sequences in the field, however, are sometimes unreliable.
Suppose the inhabitants of a previous site dug a large hole.
In social sciences there are many key concepts and terms that are crucial for students to know and understand.
Often it can be hard to determine what the most important social sciences concepts and terms are, and even once you’ve identified them you still need to understand what they mean.