Factors affecting organic preservation?

Question

Hi,

I'm doing a project for my high school anthro class; the project requires identifying the culture associated with a simulated artifact assemblage. I wanted to tackle this project by narrowing down the culture's possible geographical locations rather than guessing arbitrary areas. The good organic preservation conditions seems to be my best bet for narrowing down the possible locations: well-preserved vegetable fibers, animal hide, incised bone, wood, and a bark bowl were included in the assemblage. I'm guessing that the culture was from the mid to late Archaic period based on the style of the bifaces and the woven fiber shoes. I've been trying in vain to find a scholarly article that identifies all the locations known for good organic preservation conditions. Is there anyone with an Archaeology or Anthropology degree who would know of such a source?

Answer 1

Good luck trying to find a scholarly article that identifies all the locations known for good organic preservation conditions.  There are too many to be listed by usual means and most researchers break maps down by specific culture of interest.

Most organic materials require oxygen and moisture to decompose.  Anything which will limit one or both of these will slow down or even suspend decomposition.  The places on the earth which fit these conditions include (but is not limited to) the following:

(1)  Desserts, especially if buried deep enough to keep cooler than the surface air and out of direct sunlight.

(2)  Greatly elevated locations but especially if the items are out of direct sun.  This is because of the reduced oxygen amounts and lack of liquid water.

(3)  Peat bogs, but especially if buried below the decomposing vegetable matter which makes up the peat.  Although these are wet sites, the oxygen in the water is reduced to extremely low levels by the decomposing materials above the items.

(4)  Frozen tundra, especially below the permafrost.

(5)  Deep ocean sites below the water layers which contain dissolved oxygen.  These can be very productive if items are buried in sand.

(6)  Sites buried under deep layers of clay.  These vary from site to site, depending upon local conditions.

As for your project, if you have no stone tools among the artifacts, concentrate on the woven fiber shoes to identify the culture.

Answer 2

The problem with your question is that most cultures inhabited areas of both good and bad preservation, which vary at the micro-regional scale. Highly acidic soil, like pine forests, or excessively sandy soils, are usually bad for preservation, while less acidic soils and loess are better. However, there are also other variables. Loess, with usually high pH (low acid) is good for preserving bones and sometimes wood, but not so good for unburnt seeds or fibers. Since you have so much plant material, I would agree with other people's answers and say a marshy area is your best bet, but that is not much. The bifaces seem to be your best bet if they are diagnostic. Unless they are early-stage, that is just roughed out biface-shaped flint...

Hey Richard - he has a stone tool - it is called a biface.

Answer 3

The bogs of Europe have produced many "bog people" and and artifacts. The enviorment is anaerobic (no oxygen) and acidic enough to preserve organic remains.

Monte Verde in Southern Chile, is an inhabitation site dated to 16,000 years ago."They found the remains of the ancient camp, even wood and other perishables that archaeologists rarely find, remarkably well preserved by the water-saturated peat bog that covered the site, isolating the material from oxygen and thus decay."

http://www.unl.edu/rhames/monte_verde/Mo...

Very dry conditions will dehydrate organic matter and preserve it. Deep water with poor oxygen also inhibits decay. There have been cases where ice has preserved bodies (Otzi the members of the Franklin Expedition)

My suggestion is to determine the stone used in the bifaces. Obsidian is easily identified to it's source as are the flints and various CCS materials.What tree is the bark used in the bowl? What animal is the hide from? As example, yucca fiber, obsidian and antelope would rule out Eastern woodlands and the Southeast.