Neoarchean Terra Firma: Rare Trace Elements Show Large Landmasses Existed 2.7 Billion Years Ago
Researchers have determined the isotope composition of the rare trace elements Hafnium and Neodymium in 2.7 billion year-old seawater using high purity chemical sediments from Temagami Banded Iron Formation (Canada) and concluded that large landmasses must have existed then. The Temagami Banded Iron Formation was formed 2.7 billion years ago during the Neoarchean period and can be used as an archive because the isotopic composition of many chemical elements such as Hafnium and Neodymium directly mirrors the composition of Neoarchean seawater. These two very rare elements allow many valuable conclusions about weathering processes to be drawn. Earlier work has shown that these Canadian rocks only contain chemical elements that directly precipitated from ocean water. read more