Volcanic rocks located throughout Arizona have left us with great copper deposits.
Copper is a metallicmineral that we find in the crust of the earth. We locate it in ore deposits. Arizona has a lot of igneousrocksThese are rocks that were molten magma. The tremendous heat and pressure within the earthproduced this magma. Some of this magma was thrust or intruded into other rocks. In addition, thegroundwater found in the rocks next to the magma was also heated. This caused a chemical reaction thatalso changed other rocks located deep within the earth. Some of these rocks have big crystals along withlittle crystals. This tells us that the big rocks cooled over a long period of time, but the little crystalscooled faster. Thus, they solidified at different rates and are called copper "porphyry" (poor-fe-ree)rocks. .The magma cooled and hardened into igneous rocks. These ore deposits can be found on the surface ofour earth as well as deep within the crust of it. The surface rocks are formed due to weathering and
erosion over time. Igneous rocks may also have other precious metals besides copper inside them.
Who Knows. can anybody forward a link or recommend a good book on this topic please.