In order to use this equation for decay over a given time period, we will need the solution of a first-order differential equation.Obtaining such a solution is beyond the scope and requirements of this class, though with 1-2 years of calculus, you to could do the impossible.In many respects, igneous rocks are the easiest to date because the starting of the clocks are unambiguous. : Sedimentary rocks are, to a large degree, made from fragments of pre-existing rocks that have been broken, weathered, transported and ultimately deposited in ocean basins.

The number of parent atoms that decay in a fixed period of time, or conversely the number of daughter atoms produced, depends on the number of parent atoms present at any point in time.

Such a relationship results in an exponential decrease in the number of parent atoms remaining as a function of time, if "time" is expressed as the half life (the length of time required for 50% of an initial quantity of radioactive atoms to break down) .

Accurate measurement of either the absolute or relative abundance of trace quantities of radioactive isotopes requires sophisticated instruments, known as mass spectrometers, and instrument operators who really know what they are doing.

The technique appears to be simple and straightforward, but is actually very difficult and time-consuming.

This assumption is in many cases not valid, as daughter atoms certainly existed in the mineral or rock at the time the radiometric clock started.

The solution to this problem can be illustrated using the Rubiduim (Rb) - Strontium (Sr) system.

Our ability to interpret and understand geologic events has been significantly enhanced by the development of various tools which allow us to determine the absolute age of many rocks and/or minerals.

There are several different techniques and approaches possible, but all rely on the principles of radioactive decay of unstable isotopes of elements present in trace quantities in many rocks and minerals.

I use the term "appropriate" in the sense that the specimen to be dated must obviously contain isotopes of a well known radioactive decay series, and be suitable for precise chemical analysis.