I saw something on an alt history forum that stated than one of the reasons the bronze age and iron age was so different between the Americas and Europe was that the Americas had many copper deposits while Europe had few but the Americas had few tin deposits while Europe had many.
I have also heard that apparently the Inca were experimenting with iron upon the arrival of the Spanish and that the pacific coast cultures had iron.
I would like to know if there is any validity to this and if there are any good sources for this?
Any help would be greatly appreciated.
There are two considerable sources of tin in the Americas, one in Bolivia and one at Zacatecas, Mexico. So, yes, the geographic distribution of tin, to make tin-bronze, was limited in the Americas. Copper was more widely available in the New World, at least talking at the continental scale. Copper rich in arsenic was also used to make Arsenic bronze, which was especially popular in the central and northern Andes.
So, was copper more geologically well distributed in the Americas than tin? Sure, you could make that argument. However, it's not like you can just find tin anywhere in Europe, especially in a form that's easily exploitable in the period you're talking about. We know that tin ore from various sources was widely traded and often transported great distances, such as across the Mediterranean, which would've hardly been necessary if there were sources of comparable quality available locally.
Rather than looking for an answer to "Why was metallurgy in the Americas and Europe different?" in technology or geology only, we also have to think about culture. European metalworking traditions often emphasized the strength and utility of materials - as tools, weapons, armor. Indigenous American metallurgy (and I'm painting with an extremely broad brush here) was often more concerned with other properties of a metal object - the way an object shines, flashes, sounds. That's why the gold and silver work you'd find on the north coast of Peru 1400 years ago would have blown contemporary European gold and silversmiths out of the water. That's not to say that people in the Americas didn't make bronze tools (they did), its just that tools and weapons weren't what was pushing the boundaries of technological and methodological developments in metallurgy.
As far as Andean experiments with iron, I haven't heard of anything beyond the use of ochre as a pigment. The cultures of the Pacific NW (if that's what you mean) had iron that drifted onto the beach from shipwrecks, but I haven't seen evidence that indigenous cultures of the NW worked iron "from scratch".
Hosler, Dorothy
1995
Sound, Color and Meaning in the Metallurgy of Ancient West Mexico. World Archaeology 27(1):100–115.
Lechtman, Heather
1991
The Production of Copper-Arsenic Alloys in the Central Andes: Highland Ores and Coastal Smelters? Journal of Field Archaeology 18(1):43–76. DOI:10.2307/530150
Lechtman, Heather
1996
Arsenic Bronze: Dirty Copper or Chosen Alloy? A View from the Americas. Journal of Field Archaeology 23(4):477–514. DOI:10.2307/530550.
Quimby, George I.
1985
Japanese Wrecks, Iron Tools, and Prehistoric Indians of the Northwest Coast. Arctic Anthropology 22(2):7–15.