Figure 2. Plot of Mn concentration vs Ca concentration for 118 Paleozoic and Mesozoic calcic (> 4000 ppm Ca) black shales analyzed in this study. See Table 2 for sources of shales. Graph Reader set for Net 4.7. For other Browsers, reset Max-Min boxes using values from Pixel reader.

GRAPH READER	PIXEL READER	GRAPH SETTINGS
[Mn] in ppm	Pixel X	Min X	Max X
[Ca] in ppm	Pixel Y	Min Y	Max Y