317 



Mount Remarkable. 

 The main limestone of tlie Brighton series makes outcrops 

 on both the western and eastern sides of the mount, in 

 superior order to the autoclastic zone described above at 

 page 311. On the east-ern side, the outcrops are weathered 

 down even with the ground and, therefore, unfavourable for 

 observation. On the western side of the mount they are more 

 prominent and give good sections. (26) The rock is in all 

 respects similar to that seen in the Brighton exposures. The 

 groundmass is somewhat more crystalline than in the Brighton 

 examples, and the pellet-like spherules are abundantly- 

 developed and are of a similar type to those at Brighton. 

 There is the same feature of ferruginous cement in the 

 superficial coating, as well as at the centre of the spherules. 

 In many cases the nucleus is formed by either a rhombohedral 

 crystal of calcite, or a combination of two or three such 

 crystals. The yellowish to brownish inclusions, of an 

 ochreous kind, seen at Brighton, occur here also, but of a 

 larger size, reaching, in some cases, two inches in length. 

 These inclusions are mostly fiat with serrated edges, and they 

 contain the pellet-like objects in the same manner as the rest 

 of the stone. Specimens were gathered for examination near 

 the residence of Mr. William Gray. 



Depot Creek. 

 PL xix. 

 The fine-grained, light-coloured quartzites of the Devil's 

 Peak Range end abruptly at the Dutchman's Stern, about 

 five miles north-west of Quorn. The purple slates rise from 

 beneath these beds and continue in outcrop for four miles in 

 a northerly direction. The purple slates are underlain by the 

 Brighton limestones, which make a bold outcrop, a little to 

 the south of the Depot Creek, near the residence of Mr. 

 Fitzgerald, and then, after crossing the creek, they occupy 

 a higher level on the right bank. The thick limestone varies 

 considerably at different levels with respect to the grain of 

 the stone, the colour, and the structure. It is somewhat 

 ferruginous, giving the rock at some horizons a brownish 

 eolour. The colour varies to dark brown, in places, and to 

 a light-greenish tint at others. Like the same limestone further 

 south it has a quasi-oolitic texture, and the granules, indi- 

 vidually, vary in shape. They are mostly spheroidal, but also 

 egg-shaped, pear-shaped, elongated, subangular, or irregular. 

 The matrix is somewhat coarsely crystalline and transparent 



(26) See Howchin, ''The Geology of Mount Remarkable," 

 Trans. Ro^^ Soo. S. Austr., vol. xl. p. 551. 



