Choices:
[-] Igneous intrusion;
[-] Metamorphic Layers;
[-] loose soil;
[-] tectonic plates coliding;
[-] Physical weathering;
[-] Volcanic mountains;
[-] permineralization;
[-] Sedimentary deposits;
Q: Fact 1: Vein deposits of gold and silver are formed by igneous intrusion. Fact 2: Jewelry is made of silver, gold or platinum and is usually set with precious stones. Given the two facts above, what geological formation must occur for the availability of material for silver jewelry to occur?
A:
Igneous intrusion