zircon was the mineral in 4 ga sandstones that was dated to determine the age of the earth.
zircon was the mineral in 4 ga sandstones that was dated to determine the age of the earth.
what mineral in 4 ga sandstones was dated to determine the age of the earth?
zircon
the oldest minerals on earth are detrital zircon grains from the yilgarn craton in the mesoarchaean (3.2–2.8 ga) jack hills, western australia dated to up to 4.4 ga, meaning that granitic continental crust and probably supracrustal rocks formed during the hadean, within 200 million years of earth accretion. most hadean rocks were probably recycled into the mantle before the end of the eon, however, and such pre-4.0 ga mineral inclusions, the only traces from the earliest rock formation on earth, are rare.
supracrustal rock
section::::geological evidence.









































section::::geological evidence.:continental indicators.









































paleosols, detrital grains, and redbeds are evidence of low-level oxygen. the paleosols older than 2.4 ga have low iron concentrations that suggests anoxic weathering. detrital grains older than 2.4 ga also have material that only exists under low oxygen conditions. redbeds are red-colored sandstones that are coated with hematite, which indicates that there was enough oxygen to oxidize iron.









































section::::geological evidence.:iron speciation.
great oxidation event