556 Clarke — Geology of Western Australia. ' 



tlie associated silicates of alumina miglit lead to the inference that 

 they had once formed the bottom, of a marine lake or estuary, in 

 which they were deposited from the decomposition of the rocks 

 forming the shores ; an inference supported by the present condition 

 of the surface, viz., a series of saline lagoons and water -channels 

 among hills and knolls, which woiild be insulated at no great de- 

 pression of the horizon so as to admit the influx of the ocean, or 

 other increase of the lakes in depth. But the existence of salt in 

 some of these clays shows how, in certain instances, the saline 

 nature of the lagoons and water-channels of the interior may be 

 accoimted for withoiit reference to the ocean. 



W. B. Clakke. 

 St. Leonard's, near Sydney, 

 21st March, 1866. 



By favour of the Colonial Secretary we publish the Eev. W. B. 

 Clarke's remarks upon the Geological specimens brought in by 

 Mr. Hunt from his last visit to the Eastern interior. We have 

 on several occasions had to acknowledge the value of the remarks of 

 Mr. Clarke upon the various specimens forwarded to him, but 

 probably upon no occasion has his kindness been so valuable to the 

 colony as on the present. So far as the specimens went they have 

 enabled Mr. Clarke to give us a general idea of the constitution of 

 that portion of the interior traversed by Mr. Lefroy and Mr. Hunt, 

 and lead to the inevitable conclusion that in this great portion of our 

 territory it is almost hopeless to look for any valuable addition to its 

 mineral resources, unless possibly the specimens derived from the 

 salt-lakes and their neighbourhood were too few to enable him to 

 arrive at a definite conclusion. Mr. Clarke refers to the bitumen 

 found by the Messrs. Dempster (of which we have the sj^ecimen 

 still in our possession), and stated to have been found oozing from a 

 granite rock ; that may hereafter be worthy of more careful inspec- 

 tion, but at jDresent, however valuable it might prove, it is too remote 

 from the occupied districts to be available, with any chance of the 

 deposits proving worth trying for in a commercial point of view. 

 We have been particularly struck with the hypothesis ventured by 

 Mr. Clarke, after considering Mr. Hunt's specimens and the geological 

 data afforded by other observers, as to the possibility that the former 

 had arrived at the western edge of a Strait running from the Great 

 Bight to the North Coast. From the various articles noticed by Mr. 

 Hunt in the possession of the natives at his farthest Eastern point, such 

 as pearl shell ornaments, etc., we have before observed they argued 

 that an easy communication with the north on that parallel probably 

 exists, and this undoubtedly would be the case if Mr. Clarke's 

 hypothesis should prove to be a true one, and the country inter- 

 vening would, there is no doubt, be one easily traversed, providing 

 supplies of water are obtainable. From the knowledge we have 

 lately gained as to the country lying between Mcol Bay and King's 

 Sound, we now know, however, that no large river exists along the 

 whole line, and if the desert with waves of sand which stopped -Mr. 



