Oldest radiometrically dated Earth rock?

Question

Earth's age, inferred from meteorites? First correct answer and a easy 10 points.

Answer 1

The oldest dated rocks are about 3.8 billion years old and are found in cratonic shield where Archean basement rocks are exposed, like the Canadian Shield.

Chondritic meteorites found on Earth have been found to have equal amounts of U238 and Pb206, indicating 1 half life has elapsed. These meteorites are assumed to have formed when out solar system formed and therefore can be used to infer Earth's age. 1 half life of U238-Pb206 is 4.55 billion years.

Answer 2

The oldest rocks have been found in Canada.

If we assume that the solar system was formed from the same pool of material at the same time, meteors then make sense to use as a gauge in determining earth's age.