The third dig site was dated from the year 8400 / 2 = <<8400/2=4200>>4200 BC.
Thus, the first dig site was dated from the year 4200 - 3700 = <<4200-3700=500>>500 BC.
The second dig site was 352 years older, so it was dated from the year 500 + 352 = <<500+352=852>>852 BC.
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