286 RESEARCH IN CHINA. 
imposing, and it has been described in terms which exaggerate the steep- 
ness of its southeastward slope. Von Richthofen was thereby led to 
consider it a fault-scarp,* but there is no fault such as he inferred. 
The lowest or I-chang gorge of the Yang-tzi is cut across the Wu-shan 
limestone, which rises at the rate of about 1,000 feet a mile till the Sin- 
t’an (Middle Paleozoic) shale appears from beneath it. Further upstream 
the Ki-sin-ling (Cambro-Ordovician) limestone forms a second gorge, and 
passing from a dip of 10° to a nearly horizontal position, gives rise to the 
mesa-like heights above Huang-ling-miau (Fig. A, Plate XX XVII). 
The structure of the Paleozoics from Nan-t’ou to I-chang is thus 
recognized as a simple gentle monocline. The strike is north 50° to 60° 
east, bending eastward northeast of the Yang-tzi and westward south- 
west of it. The dip is nearly flat along the northwestern outcrop, and 
steepens to perhaps 20° to the southwest at the southwestern margin, 
along the base of the mountains. The section is the southwestern limb 
of a broad flattish anticline, which is eroded to the underlying granite. 
The width of the exposure of the Pre-Cambrian granite is about 12 
miles, 17 kilometers, from near Huang-ling-miau to the Lu-kan rocks. 
The Lu-kan gorge is a canyon across the Ki-sin-ling limestone, which dips 
northwest, and, being cut diagonally to the strike, forms cliffs along a 
stretch of 3 miles, 5 kilometers; above Sin-t’an the overlying Middle 
Paleozoic shale, which we have named from its occurrence at this point, is 
succeeded by the Wu-shan limestone, dipping 40° northwest and giving rise 
to the Mi-t’an Gorge. ‘The strike of the strata in this northern limb of the 
Huang-ling anticline is east by north along the river, but to the westward 
the beds gradually bend northward till the strike becomes west by north. 
The succeeding structure along the river is the K’ui-chéu syncline, 
which the Yang-tzi skirts along its southern margin. The K’ui-chéu (Permo- 
Mesozoic) red beds, which dip northward, give rise to a wide area of hills 
in that direction, and we do not know their extent northeastward and 
eastward. On the south are high mountains, the outcrop of the Wu-shan 
limestone along the southern side of the basin. 
Above Kuan-t’u-k’6u this mountain range is crossed by the river, 
which at that place debouches from the lower Wu-shan gorge into the 
open hill land. The strike of the gorge-making Wu-shan limestone is 
south 65° east, nearly parallel to the stream, and the dip is 70° north. 
The form of the fold in the top of the limestone at the contact with the 
overlying red beds is of a sharp V or keel, which flares widely higher up. 
Below Nan-mu-ytian the base of the Wu-shan limestone is marked 
by the occurrence of black cherts, and it may be assumed that the Sin- 

*Gestalt und Gliederung einer Grundlinie in der Morphologie Ostasiens Sitzungsberichte der K. Preuss. 
Acad. der Wissenschaften, 1900. 
