For the following mark whether it is an example of absolute time (A) or relative
ID: 156093 • Letter: F
Question
For the following mark whether it is an example of absolute time (A) or relative time (R). Write "A" or "R" after the six following examples.
a)The Calaveras fault displaces the san pablo group in the easter San Francisco Bay Area, indicating that movement on the fault is younger than the contra costa group.
b) U-Pb ages of eclogite in the Sanbagawa belt of japan are 120 million years old which makes them younger than the eclogites of the San Francisco complex of california that give Lu-Hf ages of 155-170 million years
c)Yosemite valley is incised (ie the canyon was cut) into granitic and metamorphic rocks. This shows that the development of the canyon is younger than those rocks
d)Ar-Ar ages of amphibolites in the Yuba River area of the Feather River ultramafic belf show that these rocks were metamorphosed 340 million years ago
e)The U-Pb ages of the youngest granites in the sierra Nevada is 85 million years old
f)The Wilson Grove Formation overlies the Tolay Volcanics in Sonoma County, indicating that the Wilson Grove Formation is younger than the Tolay Volcanics.
Explanation / Answer
Ans:
a) relative time (R)
b) absolute time (A)
c) absolute time (A)
d) relative time (R)
e) absolute time (A)
f) relative time (R)