Figure 3. ¹³CH₄ vs. depth in sediments from Hole 995B. The shaded region represents the model-predicted zone of anaerobic methane oxidation. The points in parentheses are duplicate samples that are part of the methane isotope data set. The large deviation between the two samples and from the general trend suggest an error that was introduced during sample processing or analysis rather than a real variation in the data. Lacking direct evidence of such a problem, however, the points are included but left off the trendline.