II2 RESEARCH IN CHINA. 
garnet-biotite and chlorite-schists with banded gray and reddish-brown 
quartzites, even the quartzites being more or less schistose. More marble 
follows, but this member is much thicker than the first and is not inter- 
bedded with schists. The rock is white and medium grained, and certain 
layers contain bunches of white needle-like crystals, which are probably 
tremolite. The white marble rests upon quartz-biotite-schist and lies in an 
overturned syncline, the northern limb of which is. cut off by an overthrust, 
which brings schists and quartzites upon it from the north. ‘The fault is 
not parallel to the strike of the synclinal beds, but trends more toward 
the east, and there is, therefore, along the western tributary of the T’ai- 
shan-ho, a more complete sequence of the underthrust rocks. The white 
marble is there followed on the north by chloritic and sericitic schists 
and schistose dark quartzites, which appear to be a recurrence of the 
strata observed on the southeast side of the marble. The garnet-schist 
and the thinner member of marble beneath were not observed, however, 
in this section; they are probably suppressed by minor folds adjacent to 
the overthrust, as represented in Plate XVIII. 
On following this body of marble and garnet schist into the hills 
northeast of Shang-ho-miau, it is traced to outcrops in a pass 24 miles, 4 
kilometers, from the river, where it is a tremolitic marble, lying under 
black quartzite-schist, with a strike N.25° E. and dip 70° NW. The struc- 
ture of the marble itself is nearly isoclinal, but on the northeastern slope 
from the pass the black quartzite is repeated under the marble and with 
a dip of but 50° NW. The repetition and the relations of the two dips 
indicate a synclinal structure, the eastern continuation of that observed in 
the Shang-ho-miau section. Underneath the lower outcrop of quartzite 
comes in an extensive mass of chlorite and hornblende-schist and _ biotite- 
gneiss. The contact may be one of faulting or of intrusion. 
Beyond the pass is a peak of red quartzite of the Wu-t’ai system, 
which is separated from the tremolitic marble by an overthrust that may 
be traced along the little brook which flows southwest from the pass. The 
fault is there characterized by the presence of brecciated jasper in discord- 
ant contact with garnet-schist. The hade of the fault is steep toward the 
northwest. 
Wu-t’ai-shan section (Strata 26 to 32, Plate XVIII).—The strata which 
are overthrust upon the marble and schist of the Shang-ho-miau section 
consist largely of dark-banded quartzite and siliceous marble. Just north- 
east of the T’ai-shan-ho the members lying immediately north of the fault 
line are impure ferruginous marble and calcareous arkoses, containing 
bands of jasper and thin streaks of crystalline hematite. Much larger 
pieces of the hematite were observed in the float farther down the river, and 
