Differences between these reconstructions and the modern environment can then be partitioned between climatic and other factors. The use of proxy records permits the reconstruction of climate before instrument measurments were common. This may allow improved modeling of climatic responses to perturbations, for example the ehanced greenhouse effect. In the terrestrial environment there are few depositional environments. This sediment contains many physical, biological and chemical features that are indicative of a particular environment.
Closed basin lakes, that is lakes with no out-flowing rivers, are very useful.
As climate changes they undergo large fluctations in water chemistry and depth. When the climate is arid, the closed basin lakes should be shallow and saline. Conversely, they should be deep and fresh when the climate is humid. Most of the analyses I use are performed on a core of lake sediment. A Livingston corer was used to collect most of the cores.