Obsidian hydration dating

There are a number of cave sites with evidence of seasonal occupation and use of rocks for tools.

obsidian hydration dating-45

They domesticated goats and cultivated emmer, wheat, and barley.

There was a succeeding PPNB phase in which the buildings changed to complexes of large rectangular rooms, each with small workshops attached and with plastered floors and walls.

Sickle blades, pounders, and querns were used for wild or cultivated plants in the first phase.

Artifacts include a white ware, made of mixed lime and ash and used to cover baskets, producing watertight vessels.

Occupation goes back more than 30,000 years and obsidian was brought there 20,000 years ago.

There was new fauna brought by humans in the Late Pleistocene and mid-Holocene. The first occupation phase had two levels with rectangular mud-brick houses.The layer of hydrated obsidian is visible when a slice of the artifact is examined under an optical microscope at a magnification of x 500. The land was poor for agriculture, but marine resources were exploited and the small center was quite wealthy.Hydration varies geographically, and several factors such as climate, chemical environment, and physical abrasion also affect the thickness of the layer, so that most studies are locally or regionally based. There is evidence of long-distance contact with Teotihuacan before it was abandoned, like other Maya ceremonial centers, c 900 AD. The area was also important for sources of obsidian, which was exploited from the Upper Palaeolithic onwards and was extensively traded in the Neolithic.Chemical analysis of their trace elements now allows most of the sources to be distinguished (especially by neutron activation and x-ray fluorescence spectrometry), so that the pattern of trade spreading out from each can be traced.Two dating methods have been applied to obsidian: it generally went out of favor for everyday purposes (perhaps as a result of competition from metal tools) but it continued to be used for prestige objects in some areas, especially by the Minoans and Mycenaeans.Obsidian breaks with a and is easily chipped into precise and delicate forms.

Tags: , ,