Charcoal is good for more than the barbeque

The dark-colored charcoal (left of rock hammer) from a log buried by lava was found at the base of an ‘A‘ā flow in the District of Ka‘ū on the Island of Hawai‘i. The age of this charcoal, determined by an accelerator mass spectrometer radiocarbon method, is 2075 plus or minus 36 years before present. USGS photo.