Sedimentary rocks
We do not know the actual, or absolute, age of the fossil. We can only infer.
Radiometric dating is a process in which a radioactive “parent” isotope decays into a “daughter” isotope. This decay is expressed by the half-life, which is the time that is required for 50% of the parent …show more content…
Continental drift separated these two places.
There are no eutherian mammals indigenous to Australia because these mammals were indigenous to Asia and North America, but since all the continents had been joined together, they migrated to land that is now Australia.
The Permian mass extinction happened around the same time that enormous volcanic eruptions in Siberia had been going on. Beides excessive amounts of lava and ash being dispersed, the eruptions might have produced enough carbon dioxide to raise the temperature of the globe by 6℃. This rise in temperature slowed the mixing of ocean water, which would have led to a widespread drop in oxygen concentration, which would suffocate those who would breathe oxygen, and promote the growth of anaerobic bacterias. The poisonous gas from these anaerobic bacterias would have killed off the rest of the animals and plants.
The cause of the Cretaceous mass extinction is believed to have been the collision of a large comet or asteroid with Earth. The impact from this comet or asteroid would have resulted in a cloud of debris that would have blocked off sunlight and severely disturbed the global climate for several