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The Hadean eon was succeeded by the Archean eon, with the Late Heavy Bombardment hypothesized to have occurred at the Hadean-Archean boundary. Hadean rocks are very rare, largely consisting of granular zircons from one locality (Jack Hills) in Western Australia. [6]
The Archean eon, which preceded the Proterozoic eon, spanned about 1.5 billion years and is subdivided into four eras: the Neoarchean (2.8 to 2.5 billion years ago), Mesoarchean (3.2 to 2.8 billion years ago), Paleoarchean (3.6 to 3.2 billion years ago), and Eoarchean (4 to 3.6 billion years ago).*
The Hadean and Archean are difficult eons to study, however, because they are exposed in very limited places on Earth's surface. (Since they are the oldest eons, rocks that are Hadean and Archean in age are often buried far below younger rocks at Earth's surface.)
15 paź 2024 · The Archean Eon was preceded by the Hadean Eon, an informal division of geologic time spanning from about 4.6 billion to 4 billion years ago and characterized by Earth’s initial formation. Records of Earth’s primitive atmosphere and oceans emerge in the earliest Archean (Eoarchean Era).
8 paź 2024 · The Hadean Eon is characterized by Earth’s initial formation—from the accretion of dust and gases and the frequent collisions of larger planetesimals—and by the stabilization of its core and crust and the development of its atmosphere and oceans.
24 sie 2024 · The Hadean Eon, named after the Greek god and ruler of the underworld, Hades, is the oldest eon and dates from 4.6-4.0 billion years ago. This time represents Earth’s earliest history, during which the planet was characterized by a partially molten surface, volcanism, and asteroid impacts.
11 kwi 2024 · The Hadean Eon, named after the Greek god and ruler of the underworld Hades, is the oldest eon and dates from 4.5–4.0 billion years ago. Figure \(\PageIndex{2}\): Artist’s impression of the Earth in the Hadean.
