Thomson. — Geology of Middle Clarence and F re Valleys. 307 



I have observed these concretionary rocks in the Awatere Valley between 

 Middlehurst Sta.tion Creek and the George River, and around Awajjiri. 

 Thev are present in the lower Woodside Stream, and thence along the road 

 to the Ure River, and for some distance up this valley. In the Clarence 

 Valley they occur not only at the mouth of the Dee, but at Quail Flat and 

 in the Lower Herring River, and the latter occurrence tends to link them 

 up with the Inoceramus sandstones farther up the same river. The rocks 

 immediately under the north-western Clarentian outcrop are concretionary 

 sandstones interbedded with thin argillites, and strike N. 15° W., with a 

 dip nearly vertical but steeply to the west. 



There is a series of rocks in the Ouse River which perhaps belongs here ; 

 it lies below the Clarentian rocks, but the unconformity is not well marked 

 and was overlooked on my first visit, so that I supposed they were all 

 Clarentian. The rock immediately below the Clarentian basal conglomerate 

 is a thick, massive grey sandstone containing slialy partings. Below this 

 for over two miles the rocks consist of hard black shales and hard sand- 

 stones with occasional concretions. There are many small contortions and 

 faults, and the dips are very irregular. Two conglomerates of considerable 

 thickness which appear in the series contain greywackes, cpiartzites, and 

 red jasperoid rocks, besides soft sandstones, crystalline limestone, and 

 porphyries. At the time of examination I considered them, with the over- 

 lying rocks, to be Clarentian, and from their great similarity to Clarentian 

 conglomerates elsewhere it is possible that they are of this age and are 

 involved in the pre-Notocene rocks by faulting ; but of this I saw no trace. 

 Unfortunately, owing to the amount of water in the stream, I did not 

 examine the relation of the lower conglomerate to the beds farther down 

 the stream. 



Intrusive Rocks in the Pre-Notocene. 



Intrusive rocks of various kinds have a great development in the pre- 

 Notocene rocks of the Kaikoura Range, and particularly in the Tapuaenuku 

 massif (Plate XXIV, figs. 1 and 2), the upper part of which is composed almost 

 solely of them. Owing to their hard nature they form the majority of the 

 boulders in the Dee and other tributaries of the Clarence, and also in the 

 Hodder and lower Awatere Rivers. In 1913 I described their petrological 

 characters from specimens collected from the Dee gravels, and, although 

 there are doubtless numerous other types besides those collected there, 

 the general character of the series is clearly enough apparent. The more 

 siliceous rocks consist of quartz syenites and c|uartz diorites. The less 

 siliceous are mostly fine- and coarse-grained doleritic or gabbroid rocks, 

 frequently containing olivine, brown hornblende, and biotite, and rarely 

 quartz. In addition there are hornblende lamprophyres and doleritic 

 rocks with lamprophyric affinities. The list of rock- varieties given by 

 Hector (1886, p. xxxi) does not appear to be the result of microscopical 

 examination, and may be safely neglected ; nor can McKay's identifica- 

 tions of the rock-varieties be regarded as more than a general indication 

 as to their nature. 



McKay (1890b, p. 130) considered that the rocks were injected into the 

 pre-Notocene at two widely-separated periods, the older rocks, consisting 

 of diorites, syenites, and felsite rocks resembling elvanite, being confined 

 to the pre-Notocene, while the darker-coloured and more basic rocks were 

 intruded subsequently to the deposition of the lower part of the Clarentian. 

 The latter rocks in the Awatere Vallev, between the Otterson and Tone 



