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errain here is tundra, so the rocks and their trends (the general direction in w

ID: 235479 • Letter: E

Question

errain here is tundra, so the rocks and their trends (the general direction in which the rocks are aligned) are visible. This trend, also called foliation, shows the direction in which the rocks are folded. Everything is the same color due to the green tundra plants.

The rocks to the north of the foliation line are also of granitic composition and contain the same isotopes as the rocks to the south. From the amounts of U238 and Pb206 measured in the rocks from this area indicate the 45% of one half life has passed since crystallization. The half- life of U238 is 4.5 billion years (4,500,000,000). How old are these rocks?

6109.5015, -76 42.4388 Data SIO, NOAA, U.S. Navy, NGA, GEBCo Image Landsat Coogle earth imagery Date: 12/13/2015 61003126.72" N 76"24'09.77" w elev 791 ft eye alt 131.39 mi

Explanation / Answer

45/100 x half life = 20250000000