A number of other examples proving that during the construction of polygonal masonry in Peru, it was precisely the "plasticine" technology of forming blocks from plastic masses that was used. Not softening stones, namely concrete technologies in working not with liquid concrete, but with a clay-like material.
An example of erosion in megaliths in Peru and Japan. The breed is homogeneous. Erosion cannot appear in one place; a reason is needed for that. It is very similar to the poor quality of either the composition (geo-concrete with impurities), which crumbled over time, or stuck to the formwork, got debris and also crumbled over time.
Say - also erosion? But pay attention to the embossed border protruding above the surface? Yes, this is exactly the indentation after the removal of the formwork. The same will happen in plasticine. For what purpose the surface of the block was so spoiled - one can only guess.
Formwork marks. Making them on purpose (the photo shows that this is not a natural defect of the breed), processing them mechanically - also makes no sense. Apparently, the formwork was primitive and the builders did not care too much about the appearance, about the quality of the surface of the blocks.
Promotional video:
Layers from molding are shown here. Perhaps there was a pause in the delivery of the plastic mass, the lower masses had already grabbed and when the top was added, a seam was formed. Somewhere horizontal, somewhere at an angle. Also visible are "dents" in the rock, traces of the formwork.
And here you can see the "dents" from the formwork and the bad ramming of the block on the right. Everyone thinks that this is a poor quality rock. But why was it used then? If a modern builder sees that a brick lies in the water and crumbles, he will not use it in masonry. Did the ancients really care? But if they made a mistake: they did not properly ram the mass in the formwork, then after removing it they saw a marriage. But nothing can be done, the block cannot be removed and replaced with another.
Some more examples. The marriage in this masonry is not isolated. It can even be said to be systemic. The builders kept a pause between the portions of the plastics - a seam formed. But why they reacted so carelessly to the quality of the formwork is not clear.
On the left of the block, a huge cavity is generally visible. Again, we can assume: either the geo-concrete was of poor quality, or something fell into the mass. And this crumbled over time. There is also a defect on the lower block - debris (sand, ordinary clay) got in.
In the photo on the left: clearly not machining, but dents from something. Something was in the formwork.
Stone from a polygonal masonry wall. Somewhere in the yard of one of the houses. Who will argue that this was done on purpose by mechanical abrasion of the rock? Then why? It's just a dent in the plastic material of geo-concrete, mineral tuff, fluidolites - call it what you want. The essence does not change from this.
As comrade A. Sklyarov said - try to slip a banknote or a plastic card into the seam between the blocks! Lapping blocks of this quality cannot be achieved. This was done only by molding the masses.
I think that even after a number of examples in several articles, many more skeptics will argue about grinding stones for long months and years … It is their right not to notice the obvious facts.