Origin of life from apatite dating korean and black dating
Peak metamorphism experienced by these rocks at 3650 Ma occurred under conditions (Griffin et al., 1980) that could permit exchange of primitive Pb isotopes in feldspar (Cherniak, 1992) with radiogenic Pb released from U-rich phases.
Mc Gregor (2000) pointed out that the petrologically unrelated samples analyzed by Kamber and Moorbath (1998) are dominated by relatively late phases of the gneiss complex that underwent partial melting under granulite facies metamorphism, and thus their data "do not preclude the existence of very old (greater than or equal to 3800 Ma) rocks" on Akilia island. Kinny, P., 1986, 3820 Ma zircons from a tonalitic Amîtsoq gneiss in the Godthåb district of southern West Greenland: Earth and Planetary Science Letters, v.
As long as liquid water, energy sources, and organic building blocks were present, life could have emerged on these worlds as well. J., and Arrhenius, G., 1998, Phosphate and carbon on Mars: Exobiological implications and sample return considerations: Journal of Geophysical Research, v.
The discovery of terrestrial marine sediments approaching 4 b.y.
However, there is no identified candidate rock for the assimilant in the whole of the Itsaq Gneiss Complex.
Kamber and Moorbath (1998) argued that the lack of 3850 Ma Pb-Pb ages in feldspars from gneisses collected throughout southern West Greenland specifically preclude a 3850 Ma protolith age for any rocks in West Greenland. W., 1995, Carbon isotope thermometry in marbles of the Adirondack Mountains, New York: Journal of Metamorphic Geology, v.