
EnvironmentFebruary 1, 1958
Ancient Temperatures
The ratio of the oxygen isotopes in a fossil shell reflects the temperature of the water in which the shell grew. This "thermometer" is now used to study the climate of the past

Ancient Temperatures
The ratio of the oxygen isotopes in a fossil shell reflects the temperature of the water in which the shell grew. This "thermometer" is now used to study the climate of the past