What information do foraminiferal assemblages provide within sediment cores?

Foraminiferal assemblages, which are groups of tiny marine organisms found in ocean sediments, serve as valuable indicators of past ocean temperatures. These organisms have shells made of calcium carbonate, and their composition and abundance can reflect the environmental conditions in which they were formed. By analyzing the species present in sediment cores and the isotopic composition of their shells, scientists can infer temperature changes over geological time scales.

Foraminifera react to various environmental factors, including the temperature of the water in which they live. For example, different species prefer different temperature ranges, so a shift in the dominant species within a sediment core can indicate a corresponding change in sea temperature. This understanding is crucial for reconstructing historical climate patterns and understanding how ocean conditions have varied over time, which ultimately helps in climate science and modeling future changes.