Earthglide vs. Earthquake

[AngryPockets]

So, a huge earth elemental is targeted by falling debris (courtesy of an evil giant's earthquake spell). The elemental's earth glide ability says:

d20pfsrd wrote:

Earth Glide (Ex): A burrowing earth elemental can pass through stone, dirt, or almost any other sort of earth except metal as easily as a fish swims through water. If protected against fire damage, it can even glide through lava. Its burrowing leaves behind no tunnel or hole, nor does it create any ripple or other sign of its presence. A move earth spell cast on an area containing a burrowing earth elemental flings the elemental back 30 feet, stunning the creature for 1 round unless it succeeds on a DC 15 Fortitude save.

So, does the falling debris harm the elemental? Or does it "pass through" the elemental in the same way the elemental can "pass through" stone and dirt?

[Ipslore the Red]

From "as easily as a fish swims through water," it looks like it affects him about as much as rain would affect a fish- not at all.

[blahpers]

I suppose thrown or slung rocks, stone weapons, and the like wouldn't work either? I wonder how that works with a magic sling, or magic stone weapons...?

[AngryPockets]

A friend points out a consequence of such a ruling: earth elementals could not harm each other, since they are both made of earth.

[Kayerloth]

And I'd point out what happens when 2 large rocks get pounded together ... you get lots of little rocks. It can be fun to do stuff like that, I once had a fire and water elemental do mutual damage to each other (any time one attacked the other it both did and received damage). While fun, I in no way think its RAW/RAI and it is the reason why creatures have traits, resistances and or vulnerabilities etc.. And why spells often have descriptors.

Edit: I'd also point out in your quote of Earth Glide how while the elemental might move thru lava it is in no way protected from the heat and therefore damage it might receive ... any more than an Earth Elemental might not have a large chunk of its "body" knocked off by a falling rock i.e. take damage (and exactly what do you imagine a fighter wielding a heavy mace or other weapon do to the element but knock chunks out of the whole dealing damage to its structure)