Bit of both. Not the best striation or separation example but if the camera angle was better it would be easier to point it out. Here's the way to remember it (and chest is possibly the best example for locating striation):
- if you can name the muscle, that's a separation (although "chest" is not a muscle; you need the major separated)
- if you can see lines on top of the muscle that is separated, those are striations. some of the pics of franco columbo from back in the day illustrate it really well.
e: in the example you've shown the big horizontal split is actually his major being split into two heads: clavicular (top, smaller part) and sternal; the striations are the smaller lines going across, but in all fairness his striations aren't a great example
e:2: here:
http://www.tcgn.org/upload/pics/142810923qzubr.jpg
His left pec is a world-class example. Also his clavicular and sternal pectoralis major are separated brilliantly because he lifts heavy things and returns them to the ground
Ah I see, thanks. Now I know when to call it separation and when to call it striation