Baked soil contacts

Today we processed core to a depth of 2083.6 ft.  We are seeing more contacts between units marked by baked soil layers, the picture below is an example:

This is an ʻaʻa flow on top of a pahoehoe flow.  Between them is a layer of soil that was baked and oxidized to a rusty orange color when the ʻaʻa flowed over it.  In this case there are angular clasts of rock and large sediments in the contact area, which don't look like weathering products of the pahoehoe flow.  One possible explanation for them is that they are products of glacial erosion that washed down the paleo-slope of the volcano.  There is extensive evidence of glaciation on Mauna Kea dating back as far as 180,000 years ago, so if the rocks we're currently drilling are younger than the oldest glaciation, we could see glacial deposits in the core.