Modern geochemists have a similar problem. They find it hard to understand how natural gold deposits form. There is much handwaving about gold-rich fluids from deep in the earth, and chemical precipitation, but the physics does not add up.
|Title||:||Action plan for IELTS : Last-minute preparation ; practice test ; self-study guide. Academic module : [Buch + Audio-CD]|
|Author||:||Vanessa Jakeman, Clare McDowell|
|Publisher||:||Ernst Klett Sprachen - 2006|