STRUCTURAL GEOLOGY OF THE WU-T’AI DISTRICT. 163 
near its western end, the granite appears from under the Huang-t’u, rises 
high up on the slope in an anticline which is slightly overturned toward 
the south, and then sinks gradually to lower altitudes northeastward. 
Isolated hills east and north of the Shi-ling.—tThe little hill immediately 
adjacent to the Shi-ling is composed of typical upper Ki-chéu limestone 
containing a few characteristic fossils. The dips of this hill are south- 
ward on the south side of it, and northwest on the west side, indicating 
part of a pitching anticline, which is perhaps continuous with one of those 
in the mountain immediately east of it. 
The structure in the two rocky hills between Han-yang and Shi-ling 
is not simple. Several thrusts from the southeast cut out the greater 
part of the Man-t’o and Ki-chéu formations, and cause them to be overlaid 
by an unfamiliar dark limestone, which is believed to be a member of the 
Hu-t’o system. North of this limestone another thrust brings up the 
granite, but the fault was not observed on account of the covering of loess. 
The smaller castellated hill further west is equally complex, and 
closely related to the one just described. In the north base a remnant 
of the Man-t’o shale is followed by a small portion of Ki-chéu limestone, 
the crest and north slope being composed of the dark limestone, which is 
supposed to be part of the Hu-t’o. 
Vicinity of the Shi-ing.—West of the Shi-ling a dark granular limestone 
of the Hu-t’o system forms the greater part of the ridge and dips gently 
south-southeastward. It is the same as that seen in the isolated hills which 
have just been described, and is no doubt in the strike of that structure. 
The hills further west and northwest, through which the Mu-ma-ho 
runs, consist of Pre-Cambrian granite and gneiss. 
The southwestern extension of the Ki-chéu-shan, beyond the Shi-ling, 
sinks beneath the plain of Huang-t’u, but reappears again in the hills and 
plateau mapped in the southwestern part of atlas sheet B II. The detailed 
structures of the range do not persist, but the Cambro-Ordovician rocks 
range southwestward on the southeastern side of the belt of Pre-Cambrian 
rocks, which represent the great anticlinorium of the Wu-t’ai-shan. As 
is stated in the chapter on the structure of Central Shan-si, this anti- 
clinorium probably extends southwestward many miles and passes west 
of Fén-chéu-fu. 
NoRMAL FAULTING. 
Ki-chou-shan fault.—Normal faults are rare in the Wu-t’ai district, so 
rare that we discovered but one of notable character. This one, however, 
is a fault of great magnitude, and is the northeastern representative of a 
great line of fractures, which extend southwestward entirely through the 
province of Shan-si. Its appearance south of Tung-yii, where it interrupts 
the continuity of the Sinian strata, has already been referred to. We 
