CHAP. XVII. EARTHQUAKES IN NEW ZEALAND. 349 



have witnessed, so late as January, 1855, in the northern 

 island of JSTew Zealand, a sudden and permanent rise of land 

 on the northern shores of Cook's Straits, which at one point, 

 called Muko-muka, was so unequal as to amount to nine feet 

 vertically, while it declined gradually fi'om this maximum of 

 upheaval in a distance of about twenty-three miles north- 

 west of the gi-eatest rise, to a point where no change of level 

 was perceptible. Mr. Edward Eoberts, of the Eoyal Engineers, 

 employed by the British Government at the time of the 

 shock in executing public works on the coast, ascertained 

 that the extreme upheaval of certain ancient rocks followed 

 a line of fault running at least ninety miles from south to 

 north into the interior; and, what is of great geological 

 interest, immediately to the east of this fault, the country, 

 consisting of tertiary strata, remained unmoved or stationary, 

 — a fact well established by the position of a line of nullipores 

 marking the sea-level before the earthquake, both on the 

 surface of the tertiaiy and palffiozoic rocks.* 



The repetition of such unequal movements, especially if 

 they recurred at intervals along the same lines of fracture, 

 would in the course of ages cause the strata to dip at a high 

 angle in one direction, while towards the opposite point of 

 the compass they would terminate abruptly in a steep 

 escarpment. 



But it is probable that the multiplication of such move- 

 ments in the post-tertiary period has rarely been so great as 

 to produce results like those above described in Moen, for 

 the principal movements in any given period seem to be of 

 that more uniform kind spoken of at p. 334, by which the 

 topography of limited disti-icts and the position of the 

 strata are not visibly altered except in their height relatively 



* Bulletin de la Societe Geologique cated to me by Messrs. Koberts and 

 de France, vol. xiii. p. 660, 1856, where Walter Mantell. 

 I have described the facts communi- 



