Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Charcoal sample recovered from stratum 5 of Huxi (HX-5-C). (A) The whole sample before pretreatment. (B) The analyzed sample. There are some pieces that are lighter in color, although the sample received an alkali treatment (two times) to remove mobile humic acids in addition to the acid to remove carbonates. The sample is small (0.97 mg) and cannot receive any additional treatment for fear of it becoming too small. We cannot pick out the material or it will become too small.
