48 RECORDS OF THE AUSTRALIAN MtTSEUM. 



" On the Occurrence and Geological Position of Oil-bearing 

 Deposits in New 8outli Wales."* In this essay Clarke correctly 

 indicated the position of the Upper Marine Vjeds at the bottom 

 of the section, and remarked on their resemblance to the Muree 

 Series of the Hunter River Coal-field, and on their supporting 

 " a series of coal-measures, which are capped by Hawkesbury 

 rocks, all resting apparently in a nearly horizontal position on 

 each other."! This horizontility is very remarkable, and a most 

 noticeable feature, and renders it still more difficult to determine 

 the supposed unconformability, although its position may possibly 

 be marked by the occurrence of springs. At tlie same time 

 Clarke mentions that at the immediate junction of the Nattai 

 and Wollondilly, tlie lowest beds (Upper Alarine) are seen dipping 

 slightly to the west. The highest elevation attained by the Upper 

 Marine beds is five hundred feet he say.s, opposite the mouth of 

 the Nattai; and this is above sea-level, not above the level of the 

 river bed. On the Mount Queahgong section these beds seem to 

 attain a rather higher level, in fact on the eastern side of the 

 gorge the strata all appear to occupy a somewhat higher position. 



Spirifers and Stenopora, according to Clarke, occur in the 

 Marine beds, but I was not able to visit the fossiliferous spots 

 through want of time. At Singleton, however, on the Hunter 

 River, Stenopora occurs in rounded bomb-like calcareous nodules. 

 Now, in the Upper Marine beds, behind Queahgong House (Mr. 

 Maurice Hayes'), on the western bank of the Wollondilly, heavy 

 nodules of a calcareous sandstone occur, resembling cannon-balls, 

 having nuclei of calcareous matter, but not Stenopora, or other 

 fossils, so far as I saw ; otherwise the resemblance to the Singleton 

 nodules is very strong. Lines of pebbles are also seen in these beds, 

 and at times solitary pebbles occur in the ball-like segregations, 

 although not necessarily central. 



No intrusions of igneous matter, as described by Clarke higher 

 up the Nattai Valley, and by the late Mr. C. S. Wilkinson near 

 Mittagong, I in a similar series of rocks, were observed. 



Kerosene Shale has been found at several places in the valley 

 in the Upper Coal-measures, but has not been worked successfully 

 so far. 



The Rev. W. B. Clarke, speaking generally of this magnificent 

 valley, says " Nothing can so clearly mark the origin of the deep 

 ravines by continuous washings and erosions (probably after some 

 dynamical action had fissured the country), as the fallen blocks 

 of the plateau, and the pebbles which cover the face of the country 



* Quart. Journ. Geol. Soc, 1860, xxii., pp. -139-448. 



t Ibid, p. 443. 



X Ann. Eeport Dept. Mines N.S. Wales for 1881 [1882], p. 141. 



