STRUCTURAL GEOLOGY OF SHAN-TUNG. 65 
In the Sin-t’ai district normal faults are developed in a complex 
manner, and it is probable that the structures there observed are charac- 
teristic of the W6n-ho watershed. So far as they have been accurately 
observed in detail, these faults do not follow any definite system in their 
horizontal arrangement. They run indifferently toward any point of the 
compass; they join or intersect and are frequently crooked. Neverthe- 
less, in the Sin-t’ai district they possess a definite habit of dislocation; all 
faults which run nearly north and south have the upthrow on the eastern 
side, except in one instance; and for all faults which run nearly east and 
west the upthrow is, without exception, on the northern side. By refer- 
ence to section DD, Plate XV, the effect of this relation of upthrow to 
downthrow may be seen to compensate for the dip of the Sinian strata, 
so that in going from south to north we repeatedly meet the same forma- 
tions, although the constant northern dip should bring younger strata down 
to the level of observation. This happens only in the coal-basin of Yen- 
chuang, where coal-measures and the overlying volcanic rock cover an 
extensive area. Immediately north of them, however, the Pre-Cambrian 
gneiss forms the surface of the Wo6n-ho valley, and extends northward to 
Mei-yii-shan. 
Details of faulting.—The table on page 67 gives certain details con- 
cerning the nine principal faults observed in the Sin-t’ai district. The 
faults are designated by letters, which will be found appropriately placed 
upon Plate XIV. A comparison of columns 2 and 3 permits a study of the 
relations of the direction of faulting to upthrow and downthrow sides. 
Columns 4 and 5 give the dimensions of the faults in terms of length and 
displacement; the length is necessarily somewhat indefinite, as it is rarely 
the case that the end of a fault can be even approximately determined. 
The existence of the fault is recognized where diverse formations are 
brought into contact; where the displacement is within one formation, and 
particularly where it runs into gneiss, its amount can not be determined. 
Inasmuch, however, as strata of the Sinian system are depressed below 
the present surface of erosion somewhere along each one of these major 
faults, it seems probable that the displacement is less where this is not 
the fact than where it is; accordingly, faults running into the gneiss 
are thought to have less displacement in that direction and probably to 
disappear. 
A fault which is distinguished by great length and displacement 
beyond the others is Na. It has a northwest-southeast course and is 
followed by the valleys of the Tung-w6n-ho and the Siau-w6n-ho. Its 
length, as mapped by von Richthofen, is about 75 miles, 120 kilometers; 
its throw, as determined at the coal-mines, 7 miles, 11 kilometers, northwest 
of Sin-t’ai, amounts to the full thickness of the Sinian system in this 
