Question

Describe radiometric dating and discuss three prerequisites that must be met in order to obtain a reliable radiometric date on a granite batholith. What are the various methods of radiometric dating that may be used?

Answer 1

Answer:

Radiometric dating is usually defined as a method that helps in calculating the age of rock depending on the presence of radioactive isotopes and its rate of decay. In order to calculate this, the half-life of the isotope element must be known. This method is commonly used by geologists.

The conditions that are needed to fulfill in order to determine the age of a  granitic batholith are as follows-

• The rate at which these materials decay must be a constant

• There should be an exact amount of both the parent as well as the daughter elements.

• Since it is a batholith, so it has formed from the crystallization of magma at a certain depth. So, these granitic rocks must have remained within a closed system, right from the time of its formation.

The various methods of radiometric dating that can be used to date this granitic batholith are-

• Uranium-lead dating- It is an efficient method to date the rocks that are of about 4 to 4.5 billion years.

• Potassium-argon dating- It is also commonly used to date rocks that are about 4 billion years old.