Old wood effect radiocarbon dating
Archaeologists have discovered a perfectly circular Danish ring fortress in Borgring, Denmark, that dates back to AD 975-980.
The fortress is believed to have been built during the reign of Harald Bluetooth - the King of Denmark who is often credited with the first unification of the country.
Based on this brief literature survey, we may conclude that volcanic CO is exclusively anthropogenic.
They are thought to have been made in an attempt to build a defensive network similar to that introduced by the Anglo Saxons.The Borgring fortress is the first to be discovered in Denmark since 1953, and experts believe that there are many more to be identified around the country.Lidar is a technology that measures distance by shooting a laser at a target and analysing the light that is reflected back.A narrow laser beam can be used to map physical features with very high resolution.
Researchers from Aarhus University discovered the fort using Li DAR technology, which revealed the tell-tale geometric outline of a ring fortress.Although you might imagine that there is no air in the mantle, the chemical conditions favour oxidation, and shortages of oxygen ions are rare enough to ensure a strong presence of CO rather than a representative sample of the Troposphere.