The evidence in the last core sample was intact organic vegetable matter which completely destroyed the slow deposition model of glaciation in the first place. The freeze was fast at the beginning Dexter. It supports catostrophic events as initiators.
There are a few ways a 'fast freeze' could happen. Freezing rain is one possibility as long as it never thawed after the rain, it just kept piling up as freezing rain or snowfall. Freezing to death would stop decay, all predators and scavengers would also be frozen solid and then it snowed, a lot. Fell through some thin ice on a shallow pond and the pond froze completely in a very short time and never thawed.
When attempting to compress a liquid heat will be created if compression actually takes place. With heat comes expansion, at some point they are going to equal out each other. How much heat is created at the depth of a mile (for example)? There would also be a temperature change (in the real world). If it is colder how much of the increase in density can be attributed to that specific change rather than compression. A carbonated liquid should be compressible at least a tiny bit of that is because it has a liquid that releases gases easily. Does 90W oil have less compressibility than plain water and will it shrink less or more with the same temperature change.