In Contrast to an Old Ash-Flow Deposit,an Old Ash-Fall Tuff

Multiple Choice

In contrast to an old ash-flow deposit,an old ash-fall tuff does NOT include which of the following?

A) thin layers
B) layers that become coarser-grained toward the base
C) ash that evenly coats hills and valleys
D) ash that is never welded to black obsidian
E) differences in thickness based on valleys and hills