Found a massive oil leak in my 99 Sentra

I'm losing about a quart a week.

Checked the engine bay. The oil leak seems to be around the belts area.
The belts and hoses are coated with oil.

Now I'm dreading that it's probably the crank main seal and perhaps
hoping that it's the water pump, but when a water pump goes it leaks
coolant, and this is definitely oil.

Any other possibilities? If its the crank seal, that sounds very expensive.

Thanks

CD