In collaboration with Lizzy Trower (Univ. of Colorado; who led the paper), Justin Strauss (Dartmouth), and Woody Fischer (Caltech), we have published a paper investigating silica levels in early Paleozoic oceans. The paper studied samples collected from the Road River Group in Yukon, Canada, and used SIMS analysis of silicon isotopes from co-eval radiolarians and sponge spicules to infer dissolved silicon levels. The results suggest that dissolved silicon levels were far lower than previously believed, and that early biosilicifiers had a profound impact on the early Paleozoic silica cycle. The paper, published in Geobiology, can be found here.