In procedure B how many years are represented between the top and bottom fossil bearing layers?

To determine the number of years represented between the top and bottom fossil-bearing layers in procedure B, you would typically look at the stratigraphic data or radiometric dating results provided in the context of the study. If specific dates or a range is given in the procedure, you can subtract the age of the bottom layer from the age of the top layer to obtain the total time span. Without specific data, I cannot provide an exact number of years.