[TibetanT]

First, check to make sure your oil filter is on tight.
Second, this area is where the oil cooler lives, so with that said...when was the last maintenance done?
When I do my 30K maintenance, I change out all the seals, gaskets, rollers, belts and water pump with new parts. One that most people miss is the oil cooler and its associated gasket kit, since it is very hard to remove and not much room in that area to work. (Unless of course, the engine is dropped and removed, then there is plenty of room.)

Might want to start the engine and observe the leak. It may also be leaking from the cam housing area and flowing downward which would point to a gasket needing replacement (cam housing), but this is just a guess.

Hope this helps.