Radiocarbon dating bronze sex dating in ames iowa
However, most direct radiocarbon dates on wheat grains at present are from northwest China, while there are only a few from central and eastern China.
This situation has been even worse in central China, as all sites with reported late Neolithic wheat remains have had their dates estimated from archaeological evidence such as pottery typology instead of direct dating.
Plant macro remains were collected on sieves with a smallest mesh size of 0.3 mm, air dried and then further studied in a laboratory.
All samples were weighed and measured before being sorted under a binocular stereomicroscope.
In previous studies, direct radiocarbon dating on wheat has been carried out at ten late Neolithic and Bronze Age sites and 18 direct radiocarbon dates of early wheat from nine sites have been published from central China (ESM 2).
Previously, only the Wadian site had included direct radiocarbon dating on supposedly late Neolithic wheat remains, which produced several dates of the historical period, but the original data have not been published (Zhao ).
By contrast, most of the Eastern Zhou and Han wheat samples yielded reasonable radiocarbon dates in accordance with their associated archaeological contexts.The only site with directly dated late Neolithic wheat grains yielded a result much later than 2000 , if at all, wheat was present in China, in which areas, and how significant it was in agriculture and diet at that time, as well as when it rose to prominence.