310 Trmisactions. 



the Ototara limestone, which is Ototaran, or Middle Oamaruian, in age. 

 The northern district has as the middle member of its sequence two lime- 

 stones, often separated by a phosphatic band, the lower (Aniuri) limestone 

 being relatively deep-water and chalky, and certainly older than Ototaran. 

 The closing member of the marine sequence in the southern district is 

 Awamoan (Upper Oamaruian), whereas in the greater part of the northern 

 district the closing member is Waitotaran (early Wanganuian). Both 

 districts may be again subdivided according to the age of the earliest 

 marine transgression. The sequence in the southern district commences 

 north of the Kakanui River with Ngaparan (Lower Oamaruian) beds, but 

 south of that river there are two or three localities where it commences 

 with Kaitangatan beds. The sequence in the northern district commences 

 with Cretaceous beds, which south of the Hapuku River are Piripauan 

 (Senonian), but north of that river are Clarentian (Albian). 



The reasons for uniting the Notocene rocks of north-eastern Marlborough 

 with those of south-eastern Marlborough and northern Canterbury in a 

 common diastrophic district are especially the presence in each area of the 

 Amuri limestone, Weka Pass stone, and " grey marls " ; but there are two 

 other characteristics, besides the age of the basal beds, which distinguish 

 the two subdistricts. In the northern the Amuri limestone attains an 

 enormous development, being measurable in thousands of feet, instead of 

 in hundreds as in the southern, and flint-beds are well developed. More- 

 over, although where the full sequence is preserved the Waitotaran beds 

 are present in both subdistricts, in the northern one they are separated 

 from the lower marine Notocene beds by a tluviatile deposit, the great 

 Marlborough conglomerate, which appears to have no counterpart in the 

 Waipara area, although it occurs as far south as Greenhills and Amuri Bluff. 



There are several separated outcrops of Notocene rocks in the Middle 

 Clarence Valley, due to involvement along parallel fault-lines, and in one 

 case to involvement in a synclinal depression. The fault-lines run in a 

 north-east and south-west direction, and are inclined very steeply. McKay 

 describes them as reversed — i.e., with dips to the north-west — and I have 

 not made any observations which tend to disprove this ; but in the majority 

 of sections the fault-line is obscured by slips and talus slopes. The Noto- 

 cene rocks in all cases lie to the south-east of the fault, and dip ab steep 

 angles against it — i.e., to the north-west — the lower beds resting uncon- 

 formably on pre-Notocene rocks to the south-east. The outcrops thus take 

 the form of strips, narrow in proportion to their length, and trending 

 north-east and south-west. 



The principal strip is that along the great Clarence fault, which extends 

 from the Gentle Annie Stream to the Ure Valley. In the middle part of 

 this strip, from the Bluff River to the Mead River, the Notocene rocks 

 form a simple monoclinal series with minor folding in the lower rocks. At 

 each end the rocks are folded into synclinals, that at the north-eastern end 

 being overturned and truncated by the branching of the fault, so that the 

 succession for some distance to the south-east of the fault-line is reversed, 

 and the beds from tJie limestone upwards are repeated several times. 



Along the middle part of the strip, from the Bluft' River to the Mead 

 River, the whole Notocene series up to the great Marlborough conglomerate 

 is preserved in such a way that the latter rock everywhere rests against the 

 fault at the surface. As there is no great difference in level at the surface, 

 this shows that the base of the Notocene has not been greatly warped m 

 a direction longitudinal to the fault-Une. This is not the case in the other 

 parallel faults. 



