Concrete disintigrates at about 1000 degrees fahrenheit but doesn't melt untill it reaches approximately 3000 degrees. Steel melts at around 2500 degrees so this conglomerate must have formed at around this temperature as some of the gun parts are melted. If the whole thing was to exceed the melting point of the agragate in the concrete it would end up being a form of lava or obsidian.
If a geologist in the distant future were to find one of these artifacts he would probably have no idea what he was looking at or why these man made objects ended up in the conglomerate.
Some speculation on thermite.
One of the things that could possibly cause temperatures of this magnitude would be thermite. The other one is the use of direct energy weapons which is easily diverted because it sounds like such a crazy idea to anyone who hasn't seen the information on them. However Youtube has some interesting videos that show that such things do exist and are indeed being used and have been operational for some time.
Why write about such a mundane subject?
I suppose it's because I wonder how the NIST could be working on an explanation of what happened on that fateful day, and still has not completed their report, allthough it allready contains 10,000 pages. I suppose that it's because I think that there should be an independent and open investigation. You know...like things are done in a democracy...G: