Zobrazeno 1 - 2
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pro vyhledávání: '"M. F. Newell"'
Publikováno v:
Science. 166:741-744
Five Zirconi samples from Pennsylvania, Virginia, and North Carolina yield discordant uranium-lead ages which suggest an original age of 820 million years and an episodic lead loss at 240 million years. The indicated age of lead loss is interpreted a
Publikováno v:
Journal of Geophysical Research. 70:1503-1507
K-Ar ages of 23 and 26 m.y. for pyroxene and Pb206/U238 ages of 32 m.y. for zircon were determined for monzonite and soda syenite porphyries. A K-Ar age of 55 m.y. for hornblende and a Pb206/U238 age of 494 m.y. for zircon from diorite porphyry are i