I'll make a dry guess...
Strong reflection under a volcanic shield from a presumably hydrothermal system. Lots of heat and electrolytes...maybe?
Maybe too obvious.....
Hmmm, basil menting under the northern ice cap?
All depends what the meaning of suprise (and is) is. If it turns out to be something that Steve Clifford predicted 15 years ago, then calling it a suprise could be, hmmmm....not so accurate.
Can't wait though, shaping up to be another Spacer's X-mas.