Silicon lavas have a temperature of 800-900 gr., And basalt (except for silicon, they contain oxides of aluminum, iron, magnesium) - 1200-1300 gr.
In our understanding of volcanic eruptions, there are always two last options. Many have not even heard of cold volcanoes, mud volcanoes. It is because of this stereotype that many people find it difficult to perceive the information that a huge part of the rocks on Earth are not only of sedimentary or basaltic origin, but, in fact, mud, from low-temperature volcanoes and calderas, like the Yeluston volcano in the USA.
I am constantly asked in the comments where are the outlets of cold fluidolites, geobetones now. It turns out that something like this is regularly erupting in northern Tanzania:
Ol Doinyo Lengai volcano in Tanzania. Old magma already has gray and white shades corresponding to carbonates.
Promotional video:
It can be seen that the black lava gradually turns into white masses. In fact, it is a mud volcano with outlets of superheated solutions of minerals. According to information from volcanologists, it flows almost like water. It is possible that in addition to carbonates, it contains a large percentage of water.
Fresh smudges along the old, already whitened lava.
As proof that these carbonate lavas are precisely the outcrops of superheated masses from a mud volcano, the fact that the melting temperature of sodium carbonate is 854 gr. Potassium carbonate - 891 gr. (data from wikipedia). And the temperature of carbonate lavas is only 510-600 degrees. And how this lava is formed - scientists are still arguing.
So what's all this geological information for? And to the fact that these low-temperature lavas, volcanic tuffs during the time of active geological activity, and even post-catastrophes, could have a different chemical composition. Some did not immediately turn to stone. And they could have been used by ancient builders.
Perhaps the Rodadero rock in Sacsayhuaman, Peru is an ancient outcrop of such lavas, tuffs. The ancients scooped up unfossilized masses from it and built polygonal masonry.
Tuff masses of the Phrygian valley in Turkey.