321 



Isle Buache, or Garden Island, consists of the same highly cal- 

 careous sandstone which forms so considerable a portion of this 

 part of the Australian coast. 



April 13. — The Rev. Henrv Browne, A.M. Head Master of the 

 London University School, was elected a Fellow of this Society. 



A paper was read, dated at Sydney, New South Wales, 14th Oc- 

 tober, 1830, and entitled, "An Account of the limestone caves at 

 Wellington Valley, and of the situation, near one of them, where 

 fossil bones have been found :" by Major Thomas L. Mitchell, F.G.S., 

 &c. Surveyor-General of New South Wales. 



Wellington Valley is about 170 miles west of Newcastle on the 

 eastern coast of Australia. It forms the ravine of the river Bell, one 

 of the principal sources of the Macquarrie, which river it joins, below 

 the places described in the paper, after a course of about six miles in 

 a direct line from south to north ; the Macquarrie itself at the point 

 of junction running nearly from east to west, in its progress towards 

 the swamps of the interior, where it disappears. 



The rock, through which the vailey has been excavated, is lime- 

 stone, much resembling in external characters that of the carbonife- 

 rous series of Europe. This appears on both sides of the valley above 

 the alluvial deposits in the bottom, and extends on the east to the 

 height of about 100 feet above the stream. On the west of the val- 

 ley, hills of greater height run parallel to the limestone, consisting 

 of a red sandstone and conglomerate ; and a range of heights on 

 the east of it is composed of trap rocks. The basis of a tract, still 

 further eastward, which divides the watershed of the interior, from 

 that which sends its streams to the sea, is granite. 



The rugged surface of the limestone tract, in several parts of which 

 the bare rocks are exposed, appears to abound in cavities, the orifices - 

 of caves and fissures ; two of which, the more immediate subject of 

 this communication, are about eighty feet above the stream of the 

 Bell, on its eastern side ; the first being a cave about 300 feet in 

 extent ; the second apparently a wide fissure in the limestone, par- 

 tially filled up. 



The Cave agrees in structure with many of those well known from 

 the descriptions of Dr. Buckland and other writers : it descends, at 

 first, with a moderate inclination ; and about 125 feet from the mouth, 

 the floor is thickly covered with a fine dry reddish dust, in which a 

 few fragments of bones, apparently of kangaroos, occur. The ca- 

 vern in different places affords beautiful stalactites and stalagmitic 

 incrustations. Irregular cavities in the roof seem to lead towards the 

 surface of the hill ; and at the remotest part the floor is covered with 

 a heap of dry white dust, so loose and light, that one of the ex- 

 ploring party sunk into it up to the waist. This dust, when chemi- 

 cally examined by Dr. Turner, was found to consist principally of 

 carbonate of lime, with some phosphate of lime and animal matter. 

 In fine, the cave appeared to terminate in a fissure nearly vertical, 

 with water at its bottom, about thirty feet below the lowest part of 

 the cavern, and nearly on a level with the waters of the river Bell, 

 This fissure also extended upwards towards the surface. 



