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There are few unresolved questions in the Earth Sciences which generate as much debate as the nature of the Hadean Earth: i.e. the rock record between the Earth’s formation and about 3.8 billion years ago. Current knowledge of the nature and origin of the earliest crust comes largely from studies of the mineral zircon (ZrSiO4). The oldest zircon grains on Earth (4.46 Ga) are found in Jack Hills, Australia...
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