Bartrum. — A Fossiliferoi/s Bed at Kauri Creel,-. 103 



Amongst the lower beds of the observed section at the Kawa Creek 

 locality are a series of thin greensand bands alternating with strong flaggy 

 glauconitic limestone layers up to 1 ft. in thickness, the whole comprising 

 a stratum about 15 ft. in depth, which strikes north and south and dips 

 westward at approximately 15°. A normal strike fault traverses the 

 section, accompanied by two lesser faults, and somewhat complicates its 

 interpretation. This fault has a throw varying up to aijout 40 ft., and dips 

 steeply eastward. 



Above the flaggy bands are bluish-white calcareous mudstones exposed 

 for approximately 50 ft. of height in the sea-clifl"s ; they strike nearly north 

 and south, and dip gently (at approximately 8°) westward. They are poorly 

 fossiliferous, showing macroscopically merely a few sporadic Foraminifera 

 and molluscs: Crepidula monoxijla (Less.) was the only specifically detei- 

 minate mollusc collected. The greensand and flaggy calcareous bands just 

 beneath contain very abundant Foraminifera and occasional distorted 

 brachiopods. The former have been forwarded to Mr. F. Chapman, of 

 Melbourne Museum, but his report upon them is not yet available. 



If one may judge from a rather limited number of fossils, mainly pelecy- 

 pods, brachiopods, and echinoids, in beds of the same sequence but at a 

 lower horizon, both sets of beds so far described — the flaggy bands and 

 overlying mudstone — are probably Middle or U})per Oaniaruian in age.* 



The gently upturned edges of these beds are now most regularly trun- 

 cated by an erosion-plane, rising from approximately 50 ft. above sea-level 

 at the coastal section south of the Kawa Creek to about 80 ft. just north 

 of the mouth of the Kawa, about half a mile distant. From its extreme 

 regularity it would appear to be a result of marine planation, and it is 

 clearly to be noted that this followed the gentle folding or warping and 

 faulting which have just been described as apparent in the coast section. 



On the erosion surface rest yellow to bluish sands crowded with casts or 

 actual shells of molluscs, a few bryozoans, corals, and other organisms. 

 Near the base the remains are moderately well preserved, and have fur- 

 nished the collection made by the author and listed in this paper. In 

 depth these sands reach about 40 ft. They cannot be followed northward 

 from the section now described, but what appears to be the same bed can 

 be seen near where the coastal route regains the coast a mile or so south- 

 wards after deviating inland to avoid some impassable basalt sea-cliffs, and 

 again still farther south. f 



Here they have been disrupted by this basalt and overlain by columnar 

 lava. At the more northerh^ locality, similarly, other lava or agglomerate 

 rests on a locally irregular erosion surface of the fossiliferous sands, the 

 agglomerate showing considerable variation in thickness, in places thinning 

 to 1 ft. or so, in others thickening to as much as 20 ft. Close by is exposed 

 part of the somewhat complex vent of the volcano, whence came this 

 material, and whence poured forth a flood of basaltic lava reaching pro- 

 bably several miles westward, for a small islet more than a mile from the 

 shore appears to be basaltic. The columnar jointing of the flow renders it 

 an easy prey to the great waves characteristic of this exposed coast. 



* -Ur. J. A. Thomson, who examined the bracliiopocls, reports that they are 

 certainly Oamaruian. 



■f" Hutton observed these beds and noted their unconformable relations to the 

 underlying beds, but failed to obtain any marine fossils in them. He tentatively cor- 

 related them with the Waitemata sandstones, but suspected that they might be much 

 younger. (F. W. Hutton, On the Relative Ages of the Waitemata Series and the 

 Brown Coal Series of Drury and Waikato, Trans. N.Z. Inst., vol. 3, jjp. 244-49, 1871.) 



