Excision Envelopes Once the datum symbols were all plotted, the next step was to draw boundary lines around each of the symbol types if a pattern existed, or around individual isolated symbols. After much discussion the decision was made that Bruce Chureh would draw ALL of the boundary lines due to the highly subjective nature of the task; no two people could draw the lines in exactly the same place. It is evident from a sean of the plate maps that the lines drawn are not strictly isopleths. It is also evident that additional profile data are required to adequately define the boundaries in many areas. When sufficient data have been collected, the boundary lines should be redrawn with due observance of the rules governing isopleths. Translation to Volumes The boundaries were traced onto square grid paper for each depth and each criterion line, then the curved boundaries were squared off as close as reasonably possible. Next, the enclosed squares were counted and adjustment made for the difference in scale between x and y directions. The adjusted area for each depth and activity line was then translated to volume by appropriate multiplication. The assumption was made that the activity shown on a plate extended downward through the 20 em thickness of the plate. While this procedure may not accurately portray reality it produces a number that is probably close to the volume that would actually be excised. Summation of Volumes The final product of this exercise is a table of numbers showing the volume by depth for each criterion level for each area and summarized by island. These data were NOT accumulated into a neat form due to the highly preliminary nature of the results. The procedure has been outlined, however, and is subject to refinement as additional data are collected and the entire exercise is repeated for final estimates, (Editor's Note: Sixteen pages of "maps" were drawn for this exercise, but were not distributed with the age Note. A specimen of the plate map for the 13-N-1 area of Irene is presented in Figure B-7-1. FIGURE B-7-1. PICTURE OF THE 13N1 AREA OF IRENE B-7-2