Gold is usually found with quartz (but unfortunately not the other way around) and granite which is are igneous materials so there would have to have been some magma near the surface of the earth. I have also heard that some gold was found in meteor impacts but I can't believe that would be a major source.

Marble on the other hand is metamorphosed sedimentary rock high in carbonates (think limestone). The original limestone was formed on a seabed with lots of shell forming creatures. The limestone must then be buried deep enough for the pressure and heat to bake (or pressure cook) the limestone into marble. You may find both types or rock in the same area, but unless there was a lot of deformation of the landform, you will not find marble under granite. Granite (or more likely Gneiss) would lay below the marble.

Above the marble, or by itself, you may find limestone. Limestone makes a great building material and is valuable in its own right. It is useful for gravel, walls, sculptures or for making cement.

Iron veins formed from the oceans. Iron is highly soluble in water and likes to be there. But iron likes oxygen even more and will leave water in a heartbeat if there is enough oxygen around. Before the earth had a high concentration of O2 most of the iron was in the oceans. Once the O2 level reached a critical point it joined with the iron to form iron-oxide which precipitated out of the sea water to form layers on the seabed. When the sea level dropped, or the land was uplifted it left these bands of iron available for relatively easy mining. These bands are again often found with limestone.

Many useful materials or minerals are found in mountains. Not because they are only found in mountains, but because it is easier to find them exposed. It would be possible to find gold, silver, copper, iron, marble and limestone in one mountain, but not likely.

That is probably more than you wanted, but I hope it helps.