These are often extensive surface scatters and deep Hornfels is an unusual and rare material, but is highly distinctive.
22.
Outcrops of granite tend to form depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels.
23.
The baked rock is most prominent within a few hundred feet of the intrusion, appearing as a dark gray hornfels.
24.
In the margins of these depressions there is evidence of contact baking or hornfels formation adjacent to the once molten basalt dyke.
25.
They are essentially of pyroxene-hornfels facies, have siliceous sediment or basaltic protoliths, and are respectively metapelites and metabasites.
26.
They are excessively variable in their mineralogical composition, and very often alternate in thin seams with biotite hornfels and indurated quartzites.
27.
The rocks here are hornfels, metamorphic rocks resulting from the effects of a major intrusion of granite that produced the coastal mountains.
28.
The boundary between the geological platform made of greywacke hornfels and the underlying fine-grained Brocken granite runs by the Hohe Klippen.
29.
The metamorphism was isochemical without introduction of extraneous elements and affected only the sedimentary cover rocks which were transformed into marble and hornfels.
30.
The most common hornfels ( the biotite hornfels ) are dark-brown to black with a somewhat velvety weathered faces of the rock.
