All very interesting but there are more convincing proofs. I'll list a few that mankind cannot explain....
1. Erosion on the Sphinx inconsistant with current dating. Egypt did not have enough rain to erode the sandstone unless it was 12,000 years old.
2. Plalcement of the Sphinx and the pyramids are inconsistant with current dating. Alignmnet is better at 12,000 years.
3. Buildings in the South American Andes are also placed to align with stars of 12,000 years ago.
4. Poured Iron "keys" were used to interlink stone blocks in the Andes, but even if more modern, Iron was not easily melted and poured to make individual "keys" for blocks. The Iron smelting would have to somehow travel with construction to allow an even work flow, or they had a very sophisticated production line for melting and carrying iron in the bronze age. You cannot put molten iron into a bronze ladle.
5. (This one confounds me) About 30 years ago, a Texas oil well driller brought up a petrified screw in the material from his prospective well. The screw had dimensions that matched no current measuring system, and the threads ran in the opposite direction from today's conventions.
6. A tiny, humanoid mummy was found in the recesses of a cave in the South West of the US. This too was about 30 years ago. Reports were on the front page of most newspapers for these last two items. Then all trace vanished. I cannot find any mention of them today, but I read them personally about that long ago as they made front page news.
7. The climate in the Andes at any time from about 10,000 years ago to present was such that no sufficient food crops could be grown at the altitude of the buildings to support the evident population. However, if the sea level were higher for one example, the air pressure would be higher at that altitude and would moderate the climate. That might have been so 12,000 years ago or more. No one is sure except that now the air pressure is too low.
And, Hoagland has been pretty much discredited in his Face on Mars story. Currently, he is an advocate of 2012. I have read his Face on Mars book and there are more claims in it than most realize. He includes claims about artifacts on the Moon as well. I think a better read was "The Gentle Giants of Ganymead".
K