"Things You Wouldn't Know If We Didn't Blog Intermittently."
This looks like a Mississippi Valley type lead-zinc (galena-sphalerite) deposit. If that's the case, the gold colored mineral is most likely pyrite. Chalcopyrite is typically more brassy, but mineral ID is difficult in photos. I'm going by assemblage here rather than straight mineral ID... though I'm pretty certain that the white mineral is quartz.I'll look around and see if I can find more on the mineralogy of the Romanian mine.
The MVT PbZn deposits are associated with coolish fluids moving during petroleum genesis. The Cavnic deposit is higher temperature, involving a number of stages as fluid temperatures first rose then fell. A simple list of minerals is at Mindat (though frustratingly, not by abundance or importance), and a more technical description of this ore type can be found in this pdf. (3.6 MB) Turns out, there is quite a bit of copper sulfide mineralization, as well as some other goodies.
Thank you. I'd love to prowl over a pile of their tailings.