The Holocene (0.01 mya-present)
spoch began with worldwide glacial retreat, and while the global trend
was toward warmer climates, there were also times in which the glaciers
readvanced in parts of the world (Davidson et al. 2002). It
is not known whether the Holocene marks the end of an ice age, or if it
is simply an interglacial period within an ice age (Davidson et al.