STRUCTURAL GEOLOGY OF THE MIDDLE YANG-TZI PROVINCE. 291 
Approaching Miau-ir-t’an, the Wu-shan rises steeply into the air and 
is underlain by the nearly vertical layers of the Sin-t’an shale. The beds 
turn over in a right-angled fold, and at Miau-ir-t’an the shale, which is 
sharply contorted, lies beneath the nearly horizontal limestone capping 
the hill. 
Miau-ir-t’an to Su-kia-pa, 12 miles, 19 kilometers.*—This section is a 
direct continuation of that up to Miau-ir-t’an, but with reference to the 
latter may be considered a shallow synclinorium, since the Carbon- 
iferous limestone rises higher both north and south. Above Miau-ir- 
t’an the Sin-t’an shales extend for a mile and a half at the river 
level. They rise again from beneath the Wu-shan limestone on two other 
anticlines. In the northern end of the section the shales reappear and, 
after extending over an arch of the Ki-sin-ling (Cambro-Ordovician) 
limestone, they form the broad syncline at Sii-kia-pa. The details of the 
folds are expressed in Section CC, atlas sheet d6. The deepest point of 
the synclinorium is at T’an-mu-shu-p’ing, where a stratum of coal in the 
Wu-shan limestone is extensively mined. The minor folds are numerous 
and closely appressed, and yet the level of the strata is maintained with 
remarkable uniformity until we reach the anticline of the Ki-sin-ling lime- 
stone south of Sti-kia-pa. At this point the top of the Wu-shan limestone, 
if it were not eroded, would lie at an altitude of about 7,500 feet above 
the river. At Sii-kia-pa there is a deep syncline in the Sin-t’an shale, on 
the northern side of which the Ki-sin-ling limestone again rises with a 
steep dip. 
Between Sti-kia-pa and Wu-shan-hién, a distance of 40.5 miles, 65 
kilometers, as measured on the sections, there is no question about the 
observation and interpretation of any of the major features of the structure. 
Had our rapid traverse permitted, we would no doubt have added to 
our knowledge of the details, but it is not probable that the general form 
or position of any of the larger folds would have been changed from what 
we noted. Northward from Sti-kia-pa there is, however, a complexity of 
structure which we did not fully understand in the field, but now interpret 
as an overthrust fault. This section ends with that fault, and an offset 
of 5 miles west by north is made for the next. 
Tung-kuan-k’ou to Chon-p’ing-hién.t—Between Sti-kia-pa and Tung- 
kuan-k’ou the Ta-ning-ho meanders in the Sin-t’an shale and an inter- 
mediate short section of the Ki-sin-ling limestone, and at Tung-kuan-k’ou 
it flows in the Wu-shan limestone. Near Sti-kia-pa the Sin-t’an shale 
lies normally above the Ki-sin-ling limestone, dipping south, as is shown 
not only by observations of dip on the two formations, but by the 

* Fig. 62 and atlas sheets d7 and d 6, { Fig. 62 and atlas sheet d 6. 
