Find someone with geological background to identify that outcrop of rock.
It looks very hard, granitic to me. Most of the caprock in the Panhandle
is whitish limestone, very porus showing fossil inclusions. Lake Meredith
is near the Alibates Flint Quarry where natives have gathered material for
spears, points, etc for centuries. Of course it was confiscated by the Great
White Father to put a stop to the criminal actions of locals who banded
together in a criminal conspiracy to plunder small shards for their despicable
delight to adorn their mantles with specimens. I have such contraband and
I fully intend to return it to it's natural home with the cacti, buffalo grass and
locoweed. Now if you want to spend a weekend looking for that outcrop
get a motel room at Borger and explore around the lake. The red soil and
striking white caprock of the Candian is worth the trip.