CONCLUSION AND REQUEST 175 



Here the figures are read from the datum of sealevel in feet, and their 

 order from northwest to southeast is: +11 feet, 10 inches; +; 0; — ; 

 -[- 5 feet; 0; + 15 feet; + 5 feet; + 15 to 20 feet; stream valley; 0; 

 0; — 5 feet (near stream) ; stream valley; — 7 feet; — ; — ; stream val- 

 ley; + ; +7 feet; + 5 feet, 6 inches; small fjord; — . Submergencies 

 of the coast are here usually indicated by the minus sign without accom- 

 panying figures, for the reason that it is difficult to measure the displace- 

 ment when the strandline is no longer visible. The authors of the report 

 on this earthquake say : 



"It (the uplift, editor) was complicated by movements along secondary fault 

 lines, which produced at least three (and perhaps more) distinct major blocks. 



"Accompanying this faulting was a minor fracturing apparently due to local 

 adjustments in the tilted blocks. Doubtless this minor fracturing is much 

 more common than our observations indicate, for it was discovered on more 

 than half of our expeditions into the interior when we went out of the valleys 

 away from the seacoast."^" 



Conclusion and Eequest 



The most important conclusion growing out of this study of relief and 

 fracture patterns throughout wide areas, is that thexe exists a primary 

 fracture pattern produced from two bisecting rectangular sets of frac- 

 tures, each made up of two series of parallel fracture planes subequally 

 spaced and vertical. Within this primary pattern are comprised both the 

 joint and fault systems as similar parts, the individual faults differing 

 from the joints in scale only, the displacement being measurable only on 

 the fault, and the fault pattern being in like manner distinguished from 

 the elementary joint pattern by its generally larger scale or order. 



Owing to the occurrence of somewhat wider joint spaces at regular in- 

 tervals within each series, the joint pattern is composite, or made up of 

 similar repeating units of several groups or orders. Locally in both joint 

 and fault patterns, certain of the series are either lacking or but poorly 

 developed, and locally, also, both patterns may be almost hopelessly con- 

 fused by additional and disorderly fractures which seem to defy arrange- 

 ment within any system. Lastly, the relief pattern of the earth's surface 

 is to a large extent controlled by the fracture pattern, though locally the 

 strong and weak beds of plunging folds may exert an even stronger 

 influence. 



All are agreed that the process of denudation is set in operation by 

 epeirogenic movement — differential uplift of the surface — which may thus 



»° Loc. clt., p. 63. 



