Welcome to the forum. Great info from some very knowledgable folks will be coming your way on your project.
I'm not a builder myself, but I don't think you'll get many recommendations to start disturbing a lot of rock to build your pond. Where there's rock....there's greater possibilities for leaks. Where there's fractured bedrock (kinda sounds like what you've described) the chances increase many times over. If possible, have your builder wait for some input from the builders here at pond boss.
I don't have a real deep pond because we stumbled across fragments of rock at about 8 ft and weren't sure what we'd find if we kept going. I have a shallow pond (4'-9') that doesn't leak which I can live with. What I couldn't live with is a deeper pond that does leak.
Best of luck. Keep the build pics coming.
Dam'd Waters Farm
2/3 ac dam'd stream pond
BG, HBG, RES, LMB, YP