He concluded that discontinuity patterns resulted from ecological and geological barriers at high elevations, attributable mostly to the effects of glaciation and volcanism.
A final chapter reviews recent speculations on the causes of global glaciation .
The first extinction of the Precambrian, which largely affected stromatolites and acritarchs, has been correlated with a large glaciation event that occurred about 600 million years ago.
Are these sea-level changes caused by continental glaciation ?
A popular view is that during the last glaciation a large ice sheet formed over the Tibetan plateau and that this ice sheet caused a similar split in jet-stream flow.
The Upper Palaeolithic occupies the second half of the last glaciation , ending 10,000 years ago.
Geologically young, the Rockies exhibit faulting, glaciation , and volcanism, resulting in rugged, spectacularly scenic terrain.
In Illinois, levels of diversity drop precipitously, most likely reflecting one or more genetic bottlenecks in areas that were once covered by the Wisconsin glaciation .
Silt and varved clay, probably deposited during the last stages of Pleistocene glaciation , cover the entire floor.
These hydrogeological conditions are controlled by relative land and sea level, erosion and deposition, the cold climate processes of permafrost and glaciation , and rock stress changes.