Along the central part of the body, the southern contact of the serpentinite slopes about 60° to the south and gradually decreases in dip to about 40° further west.

[1] This creek is a broad intermittent stream that transports granite wash and crosses the western end of the serpentinite outcrop.

[7] The Coal Creek Serpentinite is typically composed of lizardite cross-cut by secondary veins of chrysotile and layers of accessory magnetite, tremolite, talc, chlorite, and relict chromite.

The massive specimens of this serpentinite exhibit a lizardite mesh texture that represent pseudomorphs after olivine, pyroxene, and minor metamorphic amphibole.

[2][3][4] The contacts of the Coal Creek Serpentinite with the surrounding metamorphosed igneous rocks consists entirely of shear zones.

The Coal Creek Domain consists of metamorphosed, and deformed (foliated, sheared, and faulted) diorite and tonalite igneous plutons, including the Big Branch Gneiss, that are exposed within southeastern Llano Uplift.