Knowing the source of the sulphur for each ore body helps in determining why metals were deposited and directs the exploration strategy adopted in the search for new ore bodies. Exploration of oil is a technically sophisticated and fiercely competitive international business. The cost of trial wells, often dry is huge, and millions of dollars are saved if location of oil can be predicted more accurately prior to drilling. The same applies to finding mineral deposits such as gold, copper and nickel ores buried deep underground. The exploration industry therefore relies increasingly on modelling how, where, and when these commodities form and become trapped in rock structures, so as to target drilling in a risk-efficient pattern.
Geologists learn about oil and mineral formation by close study of the crystals that form rocks.
The time of formation of rocks and mineral deposits can be measured in millions of years from the progress of the uraniums natural and regular radioactive decay to form lead. This gives vital information on when rocks crystallised, when mineral deposits where emplaced, and when traps suitable for oil were being formed. Zircons have several concentric zones of growth, rather like tree rings, indicating they have crystallised in stages over periods of many millions of years. Conventional methods of dating zircons involve chemically dissolving the crystals in a beaker, and placing the solution in a mass spectrometer for measurement of the amount of lead that has formed from uranium decay. This unavoidably blends all the zones and masks the growth history of the crystal.