1 64 REVIEWS 



rifting and its relation to contemporary earth movements with reserva- 

 tion. At the end is a valuable bibliography amounting to thirty pages. 



R. T. C. 



Notes on the Geology of New Zealand. (To accompany Geological 

 Sketch Maps.) By P. G. Morgan. New Zealand Journal of 

 Science and Technology, Vol. V, No. i, pp. 46-57. Wellington, 

 N.Z., 1922. 



In this article, from the New Zealand Journal of Science and Tech- 

 nology, the author has given a brief outline of the areal geology of New 

 Zealand so far as it is known. The geological maps in black and white 

 which the notes are to accompany have been compiled from a number 

 of maps made at different times and by various geologists. The extraor- 

 dinarily complicated structure and the fact that New Zealand geologists 

 have differed greatly on vital points have made the task a difi&cult one. 

 The European time scale has been used to make the maps more intelligible 

 to geologists of other countries, but the New Zealand divisions correspond 

 only roughly with the European divisions. 



Certain schists, gneisses, and limestones in the South Island have 

 been considered of Archean age but contain intrusives which may be 

 as late as Early Triassic. About one-fifth of the area of the South 

 Island is classed as "undifferentiated and doubtful Paleozoic." There 

 are five small areas known where the strata contain recognizable fossils 

 and the oldest of these faunas is of Lower Ordovician age. Much 

 careful and highly detailed work will be required to make a reasonably 

 accurate map of the Paleozoic strata. The lack of fossils and the intense 

 folding will make this a formidable undertaking. The great and wide- 

 spread dynamo-metamorphism of certain of these rocks suggests that 

 there were important periods of diastrophism in Pre-Cambrian and 

 Paleozoic times. No Paleozoic rocks have yet been found on the North 

 Island. 



Mesozoic rocks are well represented in both the North and South 

 Islands. The early and middle Mesozoic strata fall into one great 

 Trias- Jura series (the Hokanui system). They are all involved in a great 

 post-Jurassic or post-Hokanui deformation. The Middle and Upper 

 Cretaceous strata which follow are separated from those below by a 

 strong and widespread angular unconformity. This unconformity marks 

 by far the greatest break in the known geologic history of New Zealand 

 and had the time scale grown up there instead of in Europe it would 



