Figure 1: Frequency distribution of the concentration of elements in the low-calcic black shales
of the Marine Sciences Group Black Shale Composite.
Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Zn, Ga
As, Se, Br, Rb, Sr, Zr, Mo, In, Sb, Cs, Ba, La, Ce, Nd, Sm
Eu, Tb, Dy, Yb, Lu, Hr, Ta, W, Th, U
Bar graph represents the percentage of samples falling within a given frequency range.
Dotted lines show the frequency distribution of Vine and Tourtelot (1970). The graph
gives the midpoint of each concentration range. See Text for further explanation of
concentration ranges and frequency distributions.