Interpretations & More Questions


Outer wall stratigraphy may consist of thin strong layers and thicker sequences of weaker layers.

What are the strong and weak layers?
Lava and pyroclastics/eolian layers.   Implies much greater volume of pyroclastics than lava and a volatile-rich environment.
Strong and weak lava layers.  Weak layers may be finely fractured by rapid cooling (probably requires water).
A cemented layer -- implies groundwater movement and an active hydrosphere.
Lava and aqueous sediments  -- implies active hydrology.