Oil leak

I was driving today when i smelt something burning, so i pulled over looked under my bonnet and noticed a fair bit of oil around the injectors! im guessing the burning smell was oil dripping onto the manifold? does anyone know where the oil would be leaking from?
 
No, i bought the car about 6 weeks ago from a local garage. They threw in a service when i bought the car and one in a years time when its due. Ive noticed the oil on the dip stick is jet black! so weather or not they've changed it il never know!
 
could be your rocker cover leaking if its on the exhaust manifold, quite common on the 197's