Hate to disagree with you, but I have been a professional geologist for over 30 years. We are making the trip this May for the first time, so I haven't seen the rocks. But this picture does not look like schist. Schist is usually thinly foliated. I can't imagine it looking shiny on its surface and with the smooth surfaces you show here. Is this really the schist? Or might it be basalt or some other ingneous rock?