Park. — TJie Loiver Mesozoic Bocks of New Zealand. 387 



0. Glavigera (Athyris) bed, calcareous pebbly sandstone. 



1. Claystones. 



2. Upper granite conglomerate. 



3. Mytiius sandstone and claystone. 



4. Spirigera sandstone. 



5. Mytiius sandstone. 



6. Spirigera and Trigonia sandstones. 



7. Lower granite conglomerate. 



8. Halobia claystones. 



9. Spiriferina claystones and sandstones. 



10. Plane beds, with Tceniopteris, Asplenium, &c. 



The parallelism of the facies existing between the Nelson 

 and Nugget Point sections is remarkable when we remember 

 the distance which separates these places. 



The details of the Nftlson sections are given in my paper 

 " On the Jurassic Age of the Maitai Formation," and need not 

 be repeated here. 



Mount Potts District, Upper Eangitata. 



The Permo-trias and succeeding Jurassic rocks, extending 

 from Mount Somers across the Harper Range westward to 

 the Southern x\lps, occur in a series of sharp folds. The core 

 of the western anticlinal fold is well exposed in Tank Gully, a 

 deep chasm excavated on the western flanks of Mount Potts, 

 situated in the upper Eangitata. Here are seen the lowest 

 beds of the Permo-trias, which consist of black carbonaceous 

 slaty shales and sandstones containing a number of well-pre- 

 served plant-remains. 



A collection of this fossil tlora made by Sir Julius von 

 Haast was submitted to the European palseobotanist Baron 

 von Ettingshausen, who distinguished six different genera, of 

 which the species were, he stated, mostly analogous to Tri- 

 assic ones.* 



The outcrop of the plant beds is very small, not much ex 

 ceeding an acre in extent. It is situated in the higher part 

 of Tank Gully, along the bottom of which it stretches for a 

 distance of about 150 yards. The lower end of the outcrop is 

 about 3,150 ft. above sea-level, and the upper part perhaps 

 200 ft. higher. The thickness of beds exposed is about 110 ft. 



The plant beds are deeply involved in the core of a sharp 

 anticline, and from their yielding character are much crushed 

 and slickensided. They are surmounted by thousands of feet 

 of sandstone and claystone, which along the axis of the anti- 

 cline are also greatly bent and crushed. 



Where the strata did not bend they have been subjected to 

 lateral shearing stress, the effects of which can still be traced 



• Trans, and Proc. N.Z. Inst., 1890, vol. xxiii., p. 241. 



