Hey up,

I live in Matlock and am familiar wi both areas....Wi like the carvin you mention below Cocking Tor, although similar to the design at Rowtor I agree wi Tiompan and say it's not prehistoric and think it looks a bit crisp. Never come across the carving but then I know more of the top of the edge; from the Turning Stone, Robin Hoods Mark down to Ravensnest, and the amount of grafitti on rocks and trees form the late 19th Century till present is incredible.
The Turning Stone was mentioned in, I think Black's Guide, as being a 'druidical remain' along wi Arbor Low......that area certainly attracted a lot of visitors because of this.
Although there's known rock art found nearby in Ashover and I've come across flint tools and flakes in the fields opposite Old Engine Farm near Cocking Tor on Holestone Moor.... so something was happening in the area.

Unlike Tiompan however....I'd say the circle cross design at Rowtor is, if not prehistoric, older than the work by Thomas Eyre. It's just too fancy and detailed to be by him......he did steps, caves, chairs, troughs, terraces, walls and enhancements etc......Eyre's Chair near the Cork Stone on Stanton Moor is another of his.....all larger cruder stuff.

In a totally non-argumentative kinda manner I kinda think just cause its not in the tradition of cup and ring rock art dont make it not......sorta thinking about ....say the Hangingstones on Ilkley Moor, pretty out there compared to the vast majority of carvings up there.....

nice one
stu