It is mainly determined by the uranium distribution in rocks of a water-bearing complex.Therefore, the uranium isotope ratio serves as some kind of natural indicator of water of a certain water-bearing complex.An hourglass is a helpful analogy to explain how geologists calculate the ages of rocks.When we look at sand in an hourglass, we can estimate how much time has passed based on the amount of sand that has fallen to the bottom.These varied applications of Pb isotopes to achieve an understanding of the ore genesis process are too diverse to be adequately discussed in a single overview chapter.Instead, this chapter focuses attention on what Pb isotopes tell us about (1) the sources of Pb nd other metals in ore deposits, (2) the interaction between hydrothermal fluids and wall rocks, (3) the influence of basement rocks and tectonic setting on Pb sources in ore deposits in magmatic arcs, and (4) the application f crustal-scale Pb isotope variations to an understanding of regional controls on ore deposition Before Pb isotopes pertinent to understanding ore genesis can be examined, we must review some basic principles of Pb isotope geochemistry (Fig. Elegant discussions of U-Th-Pb geochemistry are presented by Doe (1970), Faure (1977), Zartman and Haines (1988), Garipy and Dupr (1991), and Dickin (1995).Radioisotope geochronology in its present form is made possible by radioactive decay.Radioactive decay, also known as nuclear decay or radioactivity, is the process through which the radioactive (unstable) nucleus of an atom emits particles which lowers it to a lower energy state.
Radioactive decay involves the spontaneous transformation of one element into another.
This fact makes it possible to determine patterns of natural water filtration; to distinguish the rock of the water-bearing complex, to construct models of groundwater circulation, to establish the mixing proportions of waters of different complexes and to examine the interrelations between waters of different complexes.
PART 1: Back to Basics PART 2: Problems with the Assumptions PART 3: Making Sense of the Patterns This three-part series will help you properly understand radiometric dating, the assumptions that lead to inaccurate dates, and the clues about what really happened in the past.
The amount of time required for half of a given quantity of a parent radioactive element to decay into the daughter product is referred to as the half-life.
It is important however, that the half-life of an element is defined in terms of probability and is not the time required for exactly 50% of a given quantity to decay (e.g.