Geological formations

Question

Geological formations provide Archaeologist with what information. Provide the correct terminology for each layer in a formation and the importance.

Answer 1

Each formation is unique, but there are some general ways in which archaeologists gain knowledge from geological formations. Merely finding an artifact with another artifact such as bison bone is not enough to date it or place it in a specific culture. While archaeological findings can be carbon-dated, stratigraphy and sedimentary knowledge allow greater specificity.

Geoarchaeology is a subcategory of archaeology that helps to increase the accuracy of archaeological findings. It’s like the best practices in journalism: at least 3 sources are needed for corroboration, and the more, the better. Merely finding an artifact doesn’t tell us anything – it’s the artifact in context that gives the most accurate and thorough information possible.

To answer this question fully, you may need to be familiar with definitions of the following related terms: stratigraphy, geochronology, site formation processes, landscape reconstruction, sedimentology, geomorphology, pedology – all available in a text or other resource.

Stratigraphy and geochronology are “temporal”, related to placing an artifact or layer on a timeline. The stratigraphic layer in which an artifact is found can determine the approximate age (give or take a few hundred years) of the artifact. Then, that information can allude to which people lived there based on other known cultural data such as the type of ceramics or style of tools present. Known events such as the eruptions of Mount Mazama, which left still-visible layers of ash, can help us determine the date of an artifact found in relationship to that level.

Site formation, landscape reconstruction, and sedimentology show the changes in a location – for example, a river that is redirected after a flood, or a change in landscape after an earthquake. Site formation can reveal how long a culture used the area, what changes they made to it, and the density of the population – all instructive to archaeologists. For example, if the site existed because tools could be made out of a mineral deposit there, the archaeology would show evidence of that industry. Reconstructing the landscape allows understanding of why people settled there – a creek that has since disappeared or shifted (thus reducing water fowl, fish, and other food resources), fertile land that is now desert, etc. Sedimentology – the type and thickness of layers – tells both geologists and archaeologists where the sediment came from (e.g., a local process or transported by a flood, mud flow, or other catastrophic event).

Geomorphology and pedology show the changes in soils. A long period of drought could change a fertile area with humusy soils to desert-like conditions with a reduction in plant life evident in the soil (and layers). Processes like weathering and erosion might be the result of climate episodes lasting centuries or millennia and naturally have an effect on soils. So in many ways, knowledge of geological formations is inseparable from archaeology.