The extraction and segregation of organic compounds from core samples taken from marine sediments is used to predict climate conditions, reconstruct sea temperatures and identify the type of vegetation from the C3 ( temperate climate) and C4 ( tropical climate) isotopic mass spectroscopy ratio analysis. Biomarkers like alkenones ( 2-nonadecanone) are produced by marine algae, tetra ethers are produced by bacteria and other n-Alkanes, sterols and fatty acids are all used to chart temperature changes over hundreds of years. If the alkane chains have more double bonds then there is a linear relationship that shows lower the sea temperature.