Introduction to Ore-Forming Processes. Laurence Robb
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Название: Introduction to Ore-Forming Processes

Автор: Laurence Robb

Издательство: John Wiley & Sons Limited

Жанр: География

Серия:

isbn: 9781119232384

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СКАЧАТЬ – (Na,Ca)0.3(Al,Mg)2Si4O10(OH)2·nH2O

      3 Illite – KAl2(Si,Al)4O10(H2O)(OH)2

      4 Pyrophyllite – Al2Si4O10(OH)2

      5 Talc – Mg3Si4O10(OH)2

      6 Muscovite – KAl2(AlSi3O10)(OH)2

      7 Biotite – K(Fe,Mg)3(Al,Fe)Si3O10(OH,F)2

      8 Lepidolite – K(Li,Al)3(Si,Al)4O10(OH,F)2

      9 Chlorite – (Fe,Mg,Al)5–6(Si,Al)4O10(OH)8

      Ino (chain)

      1 Tremolite‐actinolite – Ca2(Fe,Mg)5Si8O22(OH)2

      2 Spodumene – LiAlSi2O6

      3 Wollastonite – CaSiO3

      Unknown Structure

      1 Chrysocolla – (Cu,Al)2H2Si2O5(OH)4·nH2O

      Geological Time Scale

Schematic illustration of the geological time scale after the International Commission on Stratigraphy. The ages of the various deposits and metallogenic provinces mentioned in the book are also shown.

      One of the major issues that characterized social and economic development toward the end of the twentieth century revolved around the widespread acceptance that the Earth's natural resources are finite, and that their exploitation should be carried out in a manner that will not detrimentally affect future generations. The concept of “sustainable development” in terms of the exploitation of mineral occurrences implies that current social and economic practice should endeavor not to deplete natural resources to the point where the needs of the future cannot be met. This would seem to be an impossible goal given the unprecedented population growth over the past century and the fact that many commodities may become depleted within the next 100 years. The challenge for commodity supply over the next century is a multifaceted one and will require a better understanding of the Earth system, improved incentives to promote more efficient recycling of existing resources, and the means to find alternative sources for commodities that are in danger of depletion.

Graphs depict the global production trends for oil (a), bauxite (b), copper (c), and gold (d) over the twentieth century.

      Source: After compilations in Craig et al. (1996).