Radioactive dating meteorite

03-Sep-2018 14:54

The difficulties with single-stage systems can be circumnavigated with multi-stage systems.

Though multi-stage lead samples cannot be used for generating isochrons, they can be used to produce valuable information through concordia-discordia plots.

If that system were dated at that point in time, it would fall on the isochron and give the correct age of the mineral.

However, without any uranium present, accumulation of daughter isotopes ceases even though time continues to pass.

These plots are also self-checking and are useful for dating old rocks with complex histories.

The plots can still produce valuable and accurate data using rocks that have been subjected to heating and metamorphic events (Dalrymple 20).

Such ages are very useful because they can measure time forward from some known event in the past, such as the formation of the earth.Since both decay series contain a unique set of intermediate radioactive isotopes, and because each has its own half-life, independent age calculations can be made from each (Dalrymple 20).The presence of a stable lead isotope that is not the product of any decay series (204Pb) allows lead isotopes to be normalized, allowing for the use of isochrons and concordia-discordia diagrams as dating tools.The first is that it requires single-stage leads, which are systems that begin at some initial lead composition and remain on the same growth curve throughout their histories (Dalrymple 209).The second requirement is that assumptions about the genetic relationship between the Earth and meteorites must be made.

Such ages are very useful because they can measure time forward from some known event in the past, such as the formation of the earth.

Since both decay series contain a unique set of intermediate radioactive isotopes, and because each has its own half-life, independent age calculations can be made from each (Dalrymple 20).

The presence of a stable lead isotope that is not the product of any decay series (204Pb) allows lead isotopes to be normalized, allowing for the use of isochrons and concordia-discordia diagrams as dating tools.

The first is that it requires single-stage leads, which are systems that begin at some initial lead composition and remain on the same growth curve throughout their histories (Dalrymple 209).

The second requirement is that assumptions about the genetic relationship between the Earth and meteorites must be made.

Second, using two isotopes of the same element makes the sample immune to chemical fractionation during a post-crystallization disturbance (Dalrymple 208). This model ultimately led to the development of isochrons, in which two isotopes are plotted against each other to calculate an age for the mineral or rock.