EduPaper Products Earth Mug
The interior structure of the Earth is layered in spherical shells, like an onion. These layers can be defined by either their physical properties. Earth has an outer silicate solid crust, a highly viscous mantle, a liquid outer core that is much less viscous than the mantle, and a solid inner core. The age of the Earth is 4.54 ± 0.05 billion years. This age is based on evidence from radiometric age dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples. The geological time scale defines the major units of geological time and definitive events of Earth history. For example, the Hadean eon represents the time before fossil record of life on Earth; its upper boundary is now regarded as 4.0 Ga (billion years ago). Other subdivisions reflect the evolution of life; the Archean and Proterozoic are both eons, the Palaeozoic, Mesozoic and Cenozoic are eras of the Phanerozoic eon. The two million year Quaternary period, the time of recognizable humans, is very small at this scale. Don't forget, 5% of all proceeds are donated to local Arts and Education organizations.
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