298 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 26, 



not the high land is central, as usually occurs. This well-marked 

 margin is most developed along the west and east coasts, where the 

 hills form a lofty continuous cliaiu. The former runs at a distance 

 of from 200 to 300 miles and upwards from the coast, and sometimes 

 attains an altitude of more than 4000 feet above the sea-level. Its 

 fellow, longer, loftier, and so pronounced as to form a well-marked 

 back-bone to Eastern Australia, stretches from Cape Howe to Cape 

 York, lying from 10 to 20 or 50 miles inland, and culminating in 

 the Bellenden-Ker hills (5158 ft.) at the base of the Cape- York penin- 

 sula, but thence onward gradually decreasing in height, till close 

 to Torres Strait they are seldom more than 300 feet above the sea- 

 level. 



The Cape- York peninsula now alluded to, triangular in shape, is 

 about 300 miles wide at its base, with a length thence northward to 

 Cape York of more than 400 miles. Its mountain-range, a continua- 

 tion of that further south, runs up along its eastern border, decreasing 

 in height pari 'passu with the diminishing area of the land. On 

 its east coast and within five miles of Cape York lies Albany island 

 (see Map), three miles long, on an average half a mile broad, 

 and separated from- the mainland by the Albany Pass, a narrow 

 gorge from 7 to 14 fathoms deep, and from half to three-quarters of 

 a mile broad, through which the tide rushes with great force either 

 way. Historically interesting from the fact that it was once the in- 

 tended site of Somerset, but wisely abandoned, on the recommen- 

 dation of the present Hydographer to the Admiralty, for a more 

 eligible bay on the mainland opposite, Albany island is geologically 

 interesting from the circumstance that it forms the principal centre 

 from which we now take our survey of this part of Australia. 



The range which thus forms a marked feature in the physical 

 geography of the Cape- York peninsula, consists, as it does further 

 south, of an axis of volcanic rock of varying constitution, but 

 chiefly granite, porphyry, gneiss, felspar, and quartz. Thus the 

 vicinity of Port Denison, Cape Melville, and the coast about Cape 

 Direction, and "Weymouth and Pair Capes are granitic, and the 

 pointed end of the peninsula porphyritie, while some of the off- 

 lying islands, outliers, so to speak, of the main range, likewise differ : 

 e. g. Dunk Island, the Pamily group. Lizard Island, the Porbes and 

 Hardy Islands are aU granitic, the Pranklands gneissic, and 

 Sunday Island flesh-coloured compact felspar. The islands of Torres 

 Strait may be regarded as an interrupted portion of this range, 

 which is doubtless continued into I^ew Guinea. Of these. Turtle- 

 back, Mount-Ernest, Poll, Banks, Burke, Mount- Adolphus, and the 

 Parewell Islands are aU granitic. Towards Cape York this igneous 

 axis has undergone less elevation ; still the underlying crystalline 

 rock occasionally appears above the surface as intruded masses of 

 porphyry, surrounded and overlain by more recent formations. Por 

 example, at the north end of Albany Island it forms a large boss ; 

 at Osnaburg, Bishop, Ida, and Evans Points, and at Cape York we find 

 it in bluffs and promontories ; and at Ida, York, and Eborac Islands 

 &c., in more elevated masses or isolated hills which culminate in 



