There are far to many variables to make a true accurate answer, this is coming from a medical responder BUT lots of texts say about 120 min....but that's very much debatable
Answer:
Many small organisms can be preserved within these layers of sediment through time. The changing abundances of these fossils through time can tell us whether a change in the environment or climate was gradual or abrupt. Studying fossil pollen and other fossils helps scientists to learn more about climate change.
