ix . Foster et al . ( 2012 )
Fig . 9 . pCO 2 reconstructions ( top panel ) versus carbon isotopes and Columbia basalt volcanic eruption rate ( bottom panels ) from Foster et al . ( 2012 ) for the period 11-17 Ma . Red line added .
The new data ( dark blue ) are from boron isotopes in foraminifera using the same general approach as Pearson et al . ( 2009 ) and Seki et al . ( 2010 ). The data are shown against some earlier reconstructions of the period ( green and red symbols ). Note that while there is more structure in this record than older data ( alkenone and boron ), all the new data points are below the 400 ppm value , even in the warmest part of the Miocene epoch .