List 3 ways that sediments in the ocean help scientists understand ancient climates.

Sediments on the ocean floor are like a history book for
the Earth.  It is a large scale, long term collection point for dead and decaying
organisms, rock, sand, etc. that can tell scientists at least the following three
things:

1)  What kind of organisms lived at the time of
that layer of sediment, which tells us what temperature ranges were, salinity levels, or
food systems present

2)  Level of volcanic or tectonic
activity at that time and place based on the age and structure/makeup of the
sediments/rocks

3)  Oxygen/carbon content of the
ocean/atmosphere at the time the organisms were alive or when the sediment was
formed.