Image of the coast of Baffin Island provided courtesy of Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC.

DTM staff scientist Richard Carlson and former Carnegie fellow Matthew Jackson, now at Boston University, in work published online today by Nature, concluded that six of the largest volcanic events of the past 250 million years tapped traces of Earth’s ancient primitive mantle – which predated the largely differentiated mantle of today.

Flood basalts in an area in northern Canada and Greenland contain geochemical traces matching those expected for Earth’s primitive mantle.  Carlson and Jackson’s research expanded that knowledge by documenting similar isotopic characteristics for other flood basalt provinces.

Carlson and Jackson used the isotopes of neodymium and lead to compare the 62-million-year-old basalts from northern Canada’s Baffin Island and West Greenland with those from the South Pacific’s Ontong-Java Plateau, which formed in the largest known volcanic event in geologic history.  They extended their investigation to basalts from four other flood basalts in Botswana, Russia, India, and the Indian Ocean.

The presence of signatures of the ancient primitive mantle in the six flood basalts suggests that a substantial fraction of the world’s largest volcanic events originate from a modern mantle source that is similar to the primitive reservoir discovered to be the source region for basalts in Baffin Island and West Greenland.  That source, both more fertile and richer in heat-producing elements than depleted mantle, may play an important role in the generation of the largest of Earth’s volcanic eruptions.

For more information, please see Carnegie’s press release.