Figure 37. Biogenic silica abundance at Sites 1010 and 1021, from Janecek (Chap. 16, this volume). Correlations between the two drill sites are biostratigraphic. The change in environment from high opal deposition to low opal deposition is step-like, but the structure is not yet well understood.

Figure 37. Biogenic silica abundance at Sites 1010 and 1021, from Janecek (Chap. 16, this volume). Correlations between the two drill sites are biostratigraphic. The change in environment from high opal deposition to low opal deposition is step-like, but the structure is not yet well understood.