Note
Here, we assess the relationship between productivity and iron in sedimentary records from the high-nutrient, low-chlorophyll region of the equatorial Pacific Ocean over the past million years. We find strong links between iron input, the export and burial of biogenic silica (opal) and total export production. Our data demonstrate that iron accumulation was more closely tied to the accumulation of opal than any other biogenic component, with high iron input associated with substantially increased opal sedimentation.