DISORDERLY FRACTURE ITELDS 



157 



fields have been encountered for which no law of arrangement has been 

 discovered (figure 30, a, a, a). In general, it would appear to be true that 

 in the more disorderly fracture fields the disjunctive planes of inclined 

 hade are relatively more numerous. 



Figure 30. 



-Schematic Representation of the Relations of the disorderly to the regu- 

 larly patterned Fracture Fields of Central North America 



The practically uniform pattern and the like orientation within each 

 of the orderly fracture fields, point clearly to a community of origin in 

 stress conditions throughout an area of continental dimensions. It may 



