These older rocks that are intruded by the granite are called roof pendants because they show the roof of the batholith.
Roof pendant geology.
They are exposed by erosion of the overlying rock.
In structural geology a roof pendant which also known as a pendant is a mass of country rock that projects downward into and is entirely surrounded by an igneous intrusion such as a batholith or other pluton.
The photo below shows the cretaceous granite below light colored rock and the dark colored sedimentary now metamorphic rock above.
In lay terminology sometimes rock hat is used.
The dinkey creek roof pendant includes schist quartzite hornfelds calc silicate rocks and marble.
Roof pendants usually are strongly metamorphosed through the processes of contact metamorphism during which heat and fluids from the intrusion have reconstituted the enclosed rock.
These rocks are thought to have been originally deposited sometime between the paleozoic visit link and the cretaceous period visit link of the mesozoic visit link in a shallow marine area.