Isotope analysis is the process of studying the different forms of atoms, called isotopes, in a sample. By analyzing these isotopes, scientists can gain information about the source, origin, or history of the sample. Full definition
[7] Recent evidence from stable isotope analysis of Holocene fur seal bone collagen (δ13C and δ15N) indicates that before the maritime fur trade, it was more common for these animals to breed at local rookeries in British Columbia, California, and likely along much of the northwest coast of North America. (en.wikipedia.org)
Angst et al. conducted carbon isotope analysis on fossils of Gastornis and several contemporaneous herbivorous mammals across several European sites and compared these to isotope profiles from extant birds with known diets. (science.sciencemag.org)
That the increasing amounts of CO2 in the atmosphere come from fossil fuels was already demonstrated by isotope analysis in the 1950s. (realclimate.org)