How to prove this density result?

What is the rock salts flats in UTAH make of, what is it's density, and what is the density of it's dust?

• Doing a project for physics. Going to prove that the clip from "The Core", where they used laser/ultra sound blaster to make a tunnel through the rock couldn't happen. We are doing this by looking at the dust that the blast admits and sighting the conservation of mass law. So, my question is, what type of rock did they blast through, what is it's density, and how would I find the density of the smoke it emits.

• Answer:

  Isn't it enough proof that whoever wrote this film must have been smoking something funny? If they even took Geology 101, they flunked. If it was the salt flats of Utah, (your picture is from Virginia) the composition of the salt flats are sodium chloride (halite), potassium chloride (sylvite), and some calcium sulphate (gypsum or anhydrite). Also in the salt flats are salts of magnesium. Here is an incomplete chemical analysis (add them up and you'll see what I mean) of some of the salt flat bedding: http://www.ut.blm.gov/SaltFlats/salt10.html As for the density of this rock, it is likely to be near the density of most other natural salt deposits. Jackson and Talbot's work, based on onshore salt coring, suggests a range for salt density between 2.15 to 2.20 g/cm3. From: Jackson, M.P.A. and C.J. Talbot, 1986, External shapes, strain rates, and dynamics of salt structures: Geological Society of America Bulletin, v 97, pp 305-323 As you state in your hypothesis, conservation of mass applies here, so the density of the dust is going to be the same, unless you are going to count the air that is mixed into the dust. Density of the gas produced is going to be very hard to determine. You need to estimate the combustion temperature, or plasma temperature (if that applies). I would guess that at that temperature, you could estimate the expansion of air and add in the density of whatever dust or gas is being created. Another property that might help you is that sodium chloride does not support combustion, but will break down into chlorine gas and sodium oxide at 1000 degrees Celsius. The chlorine gas would of course kill anyone who was nearby that didn't have full protection. Chlorine gas has been used as a chemical weapon since WW1. Reaching a 1000 degree temperature would be quite difficult in a solid mass of rock like the earth. See this MSDS: http://www.canexus.ca/site/assets/pdf/MSDS/chloride/2006%20NaCl%20E.pdf Pure sodium chloride melts around 800 C. The other stuff in there is likely to reduce that melting temperature slightly. The other big problem here is that from what I understand they went all the way to the core. They had to penetrate at least 30 km of rock just to reach the mantle. Somewhere along the way, the lithostatic pressure becomes so great that the hole would close itself and squash them into a small ball.