578 



V. — Summary and Conclusions. 



The leading geological features in the region that has 

 been dealt with in this paper may be summarized as 

 follows : — 



1. Mount Remarkable owes its prominent and isolated 

 form to two circumstances: — (1) The hardness and great 

 extent of its quartzitic core, and (2) the position and magni- 

 tude of its faults. 



2. While numerous minor faults are indicated, the 

 principal fractures can be referred to four main systems of 

 displacement, which are, broadly, coincident with the four 

 sides of the mountain — two being lateral and one at either 

 extremity of the mount. 



3. The main axis of the mount consists of the oldest 

 rocks exposed, while the mount is surrounded by a ring of 

 purple-slates and associated thin quartzites, which represent 

 the newest and, stratigraphically, the highest members of the 

 series. 



4. The greatest displacements have taken place on its 

 southern and eastern sides. Considering the thickness of the 

 strata in the downthrow areas, the mount at one time must 

 have been more than twice as high as it is at present. A 

 meridional fracture split the mount in two, when the eastern 

 half dropped from between 2,000 feet to 4,000 feet in vertical 

 height. The northern and southern segments, under the 

 influence of gravitational adjustments, also dropped to a like 

 extent at either end of the mount. The movements of sub- 

 sidence were gradual and extended over a lengthened period. 



5. In the process of settlement of the disturbed areas 

 there ensued differential strains, complex fractures, and 

 general crush that shattered the rocks and recemented the 

 fragments by welding them into a confused mass. These 

 effects are on a very large scale on the south-eastern and 

 southern sides of the mount, and to a less extent on the 



northern side also. 



> 



6. The subsiding segments at the northern end of the 

 mount had greatest freedom of movement to the eastward, 

 which permitted strike-faulting and a repetition of the beds, 

 but the very thick and compact purple-slates extending far 

 to the northward formed an unyielding massif, which com- 

 pelled the faulted limestones to curve back against the strike. 

 The limestones of the south-eastern face were nipped as in a 

 vice — no repetition of beds was possible — they wore mostly 

 crushed to fragments and, as in the case of the northern 

 segments, were forced back in a reverse direction to the normal 

 strike. 



