Читать книгу Geology and Mineralogy of Gemstones - Karl Wallace, David Turner R. - Страница 26

Earth System Science views the Earth as a working system, each part having an impact and an effect on the other through geological time. To understand how the Earth creates beautiful and inspiring gems, all aspects of the Earth system must be appreciated, including the atmosphere, oceans, surface tectonic processes, processes deep in the Earth, and life (Figure 2.1).

The significance of these components varies for the creation and preservation of different precious materials but all aspects tend to be tied together in one way or another. Diamonds, for example, predominantly form deep within the Earth in a region called the Upper Mantle, where very high pressures and temperatures exist. However, other processes, such as volcanism, are required to bring these diamonds through the mantle and crust to the surface. Natural processes on the Earth’s surface, such as glaciation, can move the diamonds away from their original source and leave a trail of ground kimberlite rock leading back to where the original deposit resides. Alternatively, if enough diamonds were moved by natural processes (e.g., river transport) from their primary geological location to a new secondary location, a diamond deposit could be formed far away from the original source rock. Even in this very limited example, the complexity and interconnectedness of the Earth system is obvious.