The Inca used those metals to decorate their palaces and had silverware, cups and dishes made of them.
Of course, only royalty had that.
Subduction occurs between two colliding tectonic plates
Geographers use the regional unit to map features of particular interest, and data can be compared between regions to help understand trends, identify patterns, or assist in explaining a particular phenomenon. Regions are traditionally defined by internal characteristics that provide a sense of place.
Then there would be no clean oxygen
Erosional landforms occur more often in the colder periods of the year because in this parts of the year there's usually more rain, and also there's snow ,and most importantly ice. The rain and snow contribute to the chemical decomposition of the rocks, while the ice with it's pressure contributes to the physical decomposition of the rocks, by literary increasing it's volume inside the cracks of the rocks and break them from the inside.