Processed it themselves, or traded for it. The ruins of Tiahuanaco show that the “staples” that held the top row of stone walls together were made by pouring molten metal into the slots carved into the stones for that purpose.
While looking up these ‘staples’ (wanted to see a pic) I found it impossible to avoid the ancient astronauts explanation.
As one man put it, “it seems that the Ancient Aliens meme has taken over any rational discussion about these sort of topics. As of right now, the mystery of Puma Punku has nothing to do with aliens, and anyone who lumps them together is doing us all a disservice.
For example, this guy wrote an article “debunking” the claims about Puma Punku, when all he does is say:
“So once again, we have an accomplishment by ancient craftsmen whom some paranormalists have attempted to discredit by attributing their work to aliens. This is not only irrational, it’s a non-sequitur conclusion to draw from the observations.”
and he added, “I couldn’t agree more!”
Forgot to thank you, very interesting.
There is a theory that the stones at Puma Punku had the same treatment.
"Tiwanaku monumental architecture is characterized by large stones of exceptional workmanship. In contrast to the masonry style of the later Inca, Tiwanaku stone architecture usually employs rectangular ashlar blocks laid in regular courses. Their monumental structures were frequently fitted with elaborate drainage systems. The drainage systems of the Akapana and Pumapunku structures include conduits composed of red sandstone blocks held together by ternary (copper/arsenic/nickel) bronze architectural cramps. The I-shaped architectural cramps of the Akapana were created by cold hammering of ingots. In contrast, the cramps of the Pumapunku were created by pouring molten metal into I-shaped sockets.[19] The blocks have flat faces that do not need to be fitted upon placement because the grooves make it possible for the blocks to be shifted by ropes into place. The main architectural appeal of the site comes from the carved images and designs on some of these blocks, carved doorways, and giant stone monoliths.[20]"
Metal working has been around since the 3rd or 4th generation of humans.
(Gen 4:22)