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Mesozoic-Triassic
251 million years to 199 million years ago. It lasted about 51.4 million years. A mass extinction was in this perod. -
Mesozoic-jurassic period
199.6 million years to 145.5 million years ago. The jurassic period lasted about 54.1 million years ago. The jurassic period was the golden time for dinosaurs. By the close of the Mesozoic, 10,000 to 15,000 feet of sediment accumulated in 15 recognized formations. -
Cenozoic-Quaternary
2.59 million years ago to Present.
We are living in the Quaternary Period. At present, it covers about 2,588,000 years but is ongoing. In this period we have erosion in the rockies. -
Paleozoic-Permian
299 million years ago to 251 million years ago. It lasted about 48 million years. During the Permian Period, Earth’s crustal plates configured themselves to form a single, massive continent called Pangaea. -
Paleozoic- Silurian
443.7 million years ago to 416 million years ago. It lasted about 27.7 million years. The Silurian was named for a Welsh tribe, the Silures, which lived in the area where Roderick Impey Murchison first described rocks of this age. During the Silurian Period Earth underwent considerable changes, which had important repercussions for the environment and life. In particular, Earth’s atmosphere developed an ozone layer.
