But ash is not always current. In Africa, nonetheless вЂ” and before the Holocene, through the center East and Asia вЂ” ostrich eggshells are common. Some web sites also contain ostrich eggshell ornaments produced by early Homo sapiens.
Elizabeth Niespolo, during the time a graduate student in UC BerkeleyвЂ™s Department of world and Planetary Science, splitting uranium from thorium in a lab at the Berkeley Geochronology Center. (Picture by Warren Sharp, BGC)
A graduate student in UC BerkeleyвЂ™s Department of Earth and Planetary Science, conducted a thorough study of ostrich eggshells, including analysis of modern eggshells obtained from an ostrich farm in Solvang, California, and developed a systematic way to avoid the uncertainties of earlier analyses over the last four years, Sharp and Niespolo, at the time. （更多…）