Gradual cooling of the earth

In mafic to ultramafic intrusives, however, you can get layering: Source (Bushveld Igneous Complex)A short version of the story: As a higher temperature mineral crystallizes, it can settle to the bottom of the magma chamber. I seem to recall hearing a story (from a reliable source) that even such a thing as crossbedding can form, from currents in the magma chamber.Moose

I'm pretty sure it is "a shear wave will not propagate though a liquid". If it was stopped by a solid, how did it make it though the crust?The rest of your post supports my perspective - I guess that's a "said solid, meant liquid" thing.I'd check your source(s), but you didn't supply any.Moose