In the last few years improvements in technology have allowed geologists to date single grains of some minerals in rocks
A geologist separates 5 grains of the mineral zircon, which can be dated by the Uranium-lead method, and the crystal retains parent and daughter through weathering, erosion, and deposition. Thus, dating each mineral grain only gives the age of the source rock that was eroded, to produce that sand, from which the zircon grain is derived. The 5 grains yield ages of 160, 110, 2020, 66, and 162 million years. What do these ages tell you about the age of the sedimentary strata?
A) They are between 160 and 162 million years.
B) They are younger than 66 million years.
C) They are Precambrian rocks, older than 2020 million years.
D) There are no age constraints from this data; sedimentary rocks cannot be dated by geochronology.
B
You might also like to view...
A volcanic rock with a glassy texture commonly has experienced ____________________ cooling Fill in the blank(s) with the appropriate word(s)
When air within a cloud begins to sink, it
A) cools at the dry adiabatic lapse rate B) warms at the dry adiabatic lapse rate C) cools at the saturated adiabatic lapse rate D) warms at the saturated adiabatic lapse rate
During calcification, plentiful rainfall leaches (dissolves) the important soluble minerals—nutrients such as calcium, phosphorus, and nitrogen—in the soil and carries them away
Indicate whether the statement is true or false
At present, most of the energy used in the United States is supplied by
A. fossil fuels. B. geothermal plants. C. nuclear power plants. D. hydroelectric plants.