Figure 3From: Ordovician ash geochemistry and the establishment of land plantsPhosphorus contents (wt.% P 2 O 5 ) for Ordovician tuffs. Most values exceed mean crustal value of 0.13%. Data set for Ireland [40] shows higher values in Ordovician tuffs compared to contemporaneous sediments. Detailed data and sources in Additional file 1.Back to article page