Scientists can use ice cores to tell us about the make-up of the ancient atmosphere; rubber ducks to learn about ocean currents (http://www.mnn.com/earth-matters/wilderness-resources/stories/what-can-28000-rubber-duckies-lost-at-sea-teach-us-about- if you don’t believe it!); and, most recently, snail shells to tell us about weather conditions thousands of years ago!
The researchers, led by Dr André Carlo Colonese from York’s Department of Archaeology, found snail shells that ranged from 2500 to 9000 years old and were able to analyse their carbon and oxygen isotopic composition. Studies of modern snails suggest that the 18O/16O ratio in the shells is primarily due to the isotopic composition of environmental waters and the effect of relative humidity. Because the amount of 18O in the environment is controlled by climatic conditions, the researchers were able to draw conclusions about the ancient climate from the isotopic composition of the shells. In addition, the scientists believe they can use the carbon isotope data to provide information on the vegetation around at the time.
Carrying out investigations on shell remains from a wide range of sites across Spain and Italy allowed the researchers to build up a picture of the weather conditions across the region. They concluded that while conditions on the Atlantic coast of Northern Spain were very similar to those of today, areas such as Southern Spain and Sicily in the Western Mediterranean were a lot more humid. As these discoveries relate to the time when the first farmers were arriving in Italy and Spain, the data could prove valuable for archaeologists studying these early people, as well as being a successful academic exercise in pioneering this new dating technique.
