That big snow-covered peak is Nevado de los Piuquenes massive (6025m). The left peak is Cerro Pyramide (5520m).
I was just about to mail ErikS and you some photos so you could help me out on this, but now it's not necessary.
There's a peak further south. It's shown on this photo. Do you know which one that is? It has a very steep SSE face. I can post a close up version if it helps.
I think this is actually Marmolejo (6119m, note the similar look to Cerro Morado)!
It looks VERY similar to the peak we think is Marmolejo. But looking at for example this photo and comparing it with this one, I'm sure it's not Morado.
it certainly is not Morado, that is in a different area. I was just pointing it out, simply because the similarity struck me.