Constraints on ocean volume change since the Archean

Water may be added to Earth's surface by the bombardment of large numbers o f small comets, increasing free water on Earth's surface & deepening the oc eans. Continental freeboard is tied to the ocean surface, because of the ba lance between erosion & mountain building. Addition of water will also affe ct continental thickness & area. I calculate the effect of increasing ocean volume on the balance between continental & oceanic area. One model also i ncludes crustal volume growth: Significant oceanic depths are known to exis t during the Archean, because sulphide deposits requiring deep oceans occur in greenstone belts. These observations prohibit the constant addition of large quantities of water (comparable to the present day ocean volume) thro ughout Earth history, but smaller quantities could be added.