Refining the Quaternary Geomagnetic Instability Time Scale (GITS): Lava flow recordings of the Blake and Post-Blake excursions

► 3 lavas record 2 excursions of earth's geomagnetic field at 120 and 104 ka. ► The excursions correlate with a global marine record of paleointensity variation. ► Supports hypothesis that Brunhes chron excursions temporally bundle into 2 groups. ► Provides chronostratigraphic tie points and insight on how the geodynamo operates.