444 RESEARCH IN CHINA. 
The other minerals are scattered through these dark bands in grains and 
small clusters. The iron ore which is present is frequently surrounded by 
whitish films of leucoxene and is probably ilmenite. Here and there one 
sees roundish or lens-shaped bodies of badly decayed feldspar associated 
with much epidote, zoisite, and fresh granular feldspar. 
During the severe dynamic metamorphism, of which this rock bears 
the marks, very few of its original components have escaped alteration. 
The strained condition of the grains of quartz and the arrangement of them 
in elongated stringers indicate that the ground-mass has been produced by 
the granulation of particles which were originally larger. This comminu- 
tion of the quartz has probably been accompanied by recrystallization of 
a portion of the material, especially the clayey constituents, resulting in the 
micas and certain fresh limpid quartz and feldspar grains. A few large 
grains, mostly feldspars, were only partially destroyed by granulation: in 
the zone of katamorphism they have been changed in part to epidote, 
zoisite, and calcite. 
The composition of this metamorphosed impure quartzite strongly 
suggests the unaltered quartzite, No. 144, which was found on the Ta- 
ning-ho. The former might easily have been derived from a rock similar 
to the latter by a moderate amount of mechanical deformation. 
Black quartzite gneiss, No. 114.—The magnetic quartzite is a local 
member in the series of black limestones, slates, and gray schists, which 
are crossed by the Han river, in the canyon just above Shi-ts’tian-hién. 
It is probably a portion of the Wu-shan anthracite-bearing formation, 
which is of Carboniferous age. Specimen obtained in ravine 2 miles, 3 
kilometers, south of the city. 
A blackish-gray magnetic rock irregularly banded with white lamine. 
The darker bands are rich in micas and magnetite, while the others consist 
almost entirely of quartz. The cleavage is good along the micaceous zones, 
but not throughout the rock. Although the texture of the quartzite is 
fine, yet it is visibly granular, and the flat faces along the cleavage planes 
are spangled with white and dark micas. 
The light bands consist of medium-grained quartz crystals forming 
an interlocking mosaic. Through the quartz are scattered irregular aggre- 
gates of a carbonate, the crystals of which are cloudy and exhibit in most 
cases neither twinning nor cleavage; this mineral is probably dolomite. 
In the same zones with the quartz and dolomite there are scattered flakes 
of muscovite, with grains of magnetite and apatite. Such cracks as occur 
are generally filled with minute flakes of mica. 
The dark bands consist largely of quartz of finer texture than that of 
the lighter bands. This quartzose field is thickly dotted with magnetite 
