no idea, but 30,000 years ago is about 28,000 years before any of the rune alphabets. Rune alphabets are merely variations on earlier alphabets, but the oldest alphabet doesn't get a start until about 3900 years ago, which makes even it a good 26,100 years later than this rock.
The markings should not be understood as part of an alphabet ~ rather, they are just markings ~ and that's the important part ~ they aren't accidental as far as anyone can tell.