Hey Jerry,

This should do the trick: http://gsc.nrcan.gc.ca/mindep/synth_...

For a quick summary, Magma is molten rock below the surface of the earth, and magma that makes it beyond the surface of the earth is considered to be lava. A Magma chamber on the other hand is a large pool of molten or once Molten rock found below the surface of the earth (Earth's crust).

The following url does a great job of detailing why the likelyhood of finding nickel, platinum, paladium etc... increases if Sage is able to locate a magma chamber on Jacobus. Grab a comfy chair and some tea if you plan to go through it all in one sitting, it's a bit of a longwinded (but quality) read. http://gsc.nrcan.gc.ca/mindep/synth_...

Cheers