60 RESEARCH IN CHINA. 
original igneous or sedimentary rocks appear to have developed in that 
deep zone where great pressure is the dominant factor affecting molecular 
and mass alterations. The resulting petrographic characteristics and the 
relations of the several members are described in the section of the 
preceding chapter, relating to the rocks of the T’ai-shan complex. The 
larger structures, in so far as they are those of folded rocks, may be isoclinal 
and involved with complex overthrusting; but they are intricate, as are 
the structures of the Laurentian. 
Observations on the local strike and dip of schistosity may be noted 
as follows: 
Ch’ang-hia district: 1 mile, 1.6 kilometers, northwest of Ch’ang-hia; 
gneiss; strike N. 10° W., dip 20° W. 
Mount T’ai-shan in the ravine below Heaven’s South Gate; gneiss 
and schist; strike N. 24° W., dip vertical. 
Sin-t’ai district; north of Ts’in-lung-shan; N. 40° W., dip 70-80° SW. 
Jointing.—The structures developed in rocks of the T’ai-shan complex 
under conditions of anamorphism are common to every part of the mass. 
As pointed out by Van Hise,* this is frequently characteristic of deform- 
ation in a deep-seated zone, and stands in strong contrast to disruptive 
structures developed under conditions of katamorphism. In the latter, 
rupture is confined to planes, which circumscribe blocks that remain 
unbroken. ‘The T’ai-shan complex has suffered this latter class of deform- 
ation also, the rocks being extensively jointed and thus divided into larger 
and smaller blocks. In general, the jointing is at close intervals, but occa- 
sionally there are masses in which the blocks between joints may measure 
as much as 100 feet, 30 meters. An interesting example occurs east of 
Sin-t’ai, where the striking peak, the Ts’in-lung-shan, rises 600 feet, 120 
meters, above the valley floor; the mass of the pinnacle is composed of 
huge blocks, between widely spaced joint-planes, whereas rocks of the 
surrounding valley are minutely jointed. 
It is evident that the schistosity developed in the deep zone of anamor- 
phism is older than the jointing in the zone of katamorphism. The former 
is certainly long Pre-Cambrian; the latter may have resulted during the 
elevation and denudation of the land mass in later Pre-Cambrian time, 
and this is probably the case; it may also have been produced with the 
jointing in the overlying Sinian strata, or it may have been effective 
in determining the location and direction of joints in these strata. A 
closer study than that which we were able to make of the relations and 
directions of joints in the two rock systems, where they come into contact, 
is necessary to discussion. 

* A Treatise on Metamorphism, Van Hise; U. S. G. S. Monograph xivm, page 673. 
