Geografi adalah unik dalam menjembatani ilmu-ilmu sosial (geografi manusia) dengan ilmu alam (geografi fisik). The Albian-age rocks in Nebraska sit instantly on 300 million yr outdated late Paleozoic strata. Samples of historical air trapped within the ice cores indicated that levels of carbon dioxide and methane in the environment had been lower in the course of the ice ages.
Lastly, we contend that a number of biologically-based mostly direct terrestrial migration routes that have been proposed for final 15 m.y. of the Cretaceous (Asia to India; Antarctica to Madagascar and/or India) can probably be dismissed as a result of the marine boundaries, seemingly varying from > 1000 up to 2500 km, have been simply too broad.
The research of plant fossils has supplied appreciable details about the variety and evolution of crops-including their origins, doable extinction, changes over time, and charges of evolution. Cretaceous rocks have been deposited in Nebraska from the Albian till the Maastrichtian (~a hundred and one-68 million years in the past).
Observe that Nebraska was nearly utterly inundated by marine water throughout this time interval. Research of this kind has been carried out by the Soviet paleontologist R. F. Gekker. International sea ranges were a lot increased than immediately, and a big seaway disected North America into several large landmasses.
As collections and lineages of crops grew to become higher understood, it is useful to look at the fossil knowledge with the geological and paleogeographical data related to these fossils. Research in paleobotany, paleoclimatology, paleoecology, and paleogeography collectively search to reply questions regarding life on Earth over geologic time.