Tuff question?

Question

in what environment does tuff (volcanic ash) form? it's a choice between:

an inland lake

an inland river

an ocean close to a beach

in the middle of an ocean

please help!!

Answer 1

I'd say in the middle of the ocean since that's where it's most likely to be a volcano out of all of those locations.

Answer 2

Tuff is just an ashfall deposit from a volcanic eruption.  None of your possible answers are very good.  All of the environments in your list are potential locations for the formation of an ashfall deposit.  However, river and nearshore (beach) areas are less likely to preserve the deposits because of energy considerations (ash is fine grained and will be transported easily in moving water).  Most of the ocean is not near any volcanic source so I would not favor that option as a likely place for the accumulation of tuffs.

So by default, I would go with the lake, although I am not happy with it because I have seen tuff deposits in clearly marine environments.