Sedimentary rocks can be dated using radioactive carbon, but because carbon decays relatively quickly, this only works for rocks younger than about 50 thousand years
just submitted and got it right. in a section it says, "igneous and metamorphic rocks can be dated radiometrically. however, sedimentary rocks cannot."
The answer is density, temperature, and salinity. These are the factors that makes a current that is 50 meter less deep. The other choices will create a higher amplitude of the current.
