In the next 3 stages, Larry will separate the basalt from the chert hammer debris in the different screens. The screens are; 1/2 inch, 1/4 inch, and window screen (w/s).


3hours-24minutes-22seconds long

Total time at the end of stage 3 = 5hrs-38min-22

(from 2hrs-14min to 5hrs-38min-22secs)

Total debitage recovered in this stage: 686.1g

Screen size     Material     %  found in this stage            Grams              Grams per minute (GPM)

1/2"              basalt                 2%                      13.8g               0.65GPM

1/2"              chert                   9.4%                    64.6g              0.32GPM                                            

1/4"            basalt                   5.4%                    37.1g             0.18GPM

1/4"             chert                   3.6%                    25.1g            0.12GPM

w/s            basalt                  12%                      82.8g            0.40GPM

w/s            chert                    8.9%                    61.6g            0.30GPM

Fines (too small)

chert/basalt combination            59.3%                   407.4g            1.99GPM

    Note that the fines have nearly doubled from the previous stage from 29.6% to 59.3%. Using a 1/4" screen in this stage, we would recover 50.9g (18.8+37.1) or 6.4% of the general evidence. In window screen we'd recover 133.7g or 18.4% of the general evidence.

Adding the recovered basalt from all 3 screens, we get a total of133.7g.

Adding the 1/2 and 1/4 screens, we get a total of 38.9g.

Divide 38.9 by 133.7 and we get 29% basalt recovery in 1/4" screen.

Adding the recovered chert from all 3 screens, we get a total of 151.3g.

Adding the chert for the 1/2" and 1/4", we get a total of 89.7g.

Divide 89.7 by 151.3 and we get 59.2% chert recovery in the 1/4" screen.

Basalt debitage is produced at 0.65 grams per minute.

Chert debitage is produced at 0.74 grams per minute.




To Experiment Salvage 3