“My conclusion is that the Flood was one facet of a larger global-scale tectonic cataclysm. A key aspect of this catastrophe was the rapid sinking, in conveyor belt fashion, of the pre-Flood ocean tectonic plates into the earth’s interior. The energy required for the process was derived from the earth’s gravity acting on the excess weight of these cold ocean plates relative to the hotter and less dense mantle rock into which they slid.”
Nothing in the bible about the enormous heating of the earth and oceans by the hot mantle rocks that were raised up and exposed.
There are a lot of things that are not in the Bible. But that doesn’t negate their validity. The description of the third day of Creation Week is an apparent example of isostasy. Just because the particulars are not listed in the Bible doesn’t mean that it didn’t happen.