Figure 1
From: A dilute sodium hydroxide technique for radiolarian extraction from cherts
Chert dissolution experiments using the NaOH method. Powdered chert samples (4.0 g) were dissolved in 40 mL of NaOH at different concentrations (1, 2, and 4 mol/L) and temperatures (60, 80, and 100 °C). Grey circles at 0 h show the results for a sample of 4.0 g of chert powder added to 40 mL of ultrapure water, which was centrifuged and dried for comparison. Sample KTY-220 from the Katsuyama section (upper Rhaetian) was used in the experiment. See Supplementary Tables S1 and Table S2 for data on this figure.
