ABSTRACT
In recent years, much attention has been paid to the view that the alternating cold and warm periods of the Quaternary were principally due to changes in the nature of the Earth's orbit around the Sun. This theory was first advocated by James Croll in the late nineteenth century (Croll 1867a,b, 1875) and later elaborated by Milutin Milankovitch (1941). In recent years, the mathematical basis of this astronomic theory of the ice ages has been substantially refined by Vernekar (1972) and by Berger (1978a,b, 1979). In particular, Berger (1978a,b, 1979) has provided highly detailed information on past insolation variations.
