Originally Posted by
Dinwar
Well, to be fair there is one way in which a catastrophe could wipe out a civilization and all records: if it was an island nation, and the island exploded. Krakatoa-like event or something similar. That said, such a civilization would necessarily be fairly small; they'd only have the resources of that island, after all (otherwise we'd see evidence of them). And extremely small groups tend to not develop high technology by themselves.
Maybe. But we found Akrotiri, despite Santorini's KABOOM having been larger than Krakatau's...
The problem with civilizations restricted to islands is that they are doomed to rely on sparse resources. Geology will impose severe limitations to the types of mineral resources avaliable. If its a Hawaii-like island, or even Iceland, for example, they will be forever restricted to basalt and obsidian. No copper, no iron, no tin. I guess an island chain like Japan would be the minimum nedded to have enough diversity of mineral resources.
Jodie, sedimentation rates are very variable. Another thing you must take in to account is that deserts do receive rains and flash floods as well as temporary streams are important when it comes down to shape desert landscapes. Add to this salar-type lakes and you'll see there's absolutely no problem with thick accumulations of sediments happening relatively fast. Do not forget also climate variations. They happened in the past, will happen again and are actually happening. Again, whatever was your source regarding Tiwanaku, its lacking knowledge.
At last but not least, remember- the "you can't know everything" is flawed. Its the god-in-the-gaps.