Читать книгу Earth Materials - John O'Brien - Страница 72

This section provides a brief introduction to the uses of some radioactive isotopes and stable isotopes important in the understanding of Earth materials and processes. Isotope studies provide powerful insights concerning the age, behavior and history of Earth materials. In geology, a thorough understanding of both stable and radioactive isotopes is essential for determining the ages and origin of minerals and rocks. Isotope ratios, determined by mass spectroscopy, are also instrumental in understanding a variety of other phenomena discussed in this book, including the determination of:

1 Source rocks from which magmas are derived.

2 Origin of water on Earth's surface.

3 Timing of mountain building events involving igneous intrusions and metamorphism.

4 Timing of unroofing of such rocks and the dispersal of their erosional products by sedimentary agents.

5 Source rocks for petroleum and natural gas.

6 Changes in ocean water temperatures, biological productivity and circulation.

7 History of ice age glacial expansions and contractions.

8 Climate change.