526 [Feb. 5, 1845.] 



merate, from 200 to 300 feet thick, through which the river makes 

 its way. At St. Peters are low hills more decidedly granitic. 

 Near Stuckeys farm are numerous fragments of crystalline rock, 

 the surface of which is much worn, as is the case with other cal- 

 careous rocks all over New South Wales. No traces of fossils 

 have been found in these limestones. 



The author remarks that the greenstone becomes compact near 

 the marble, and assumes a bottle-green colour, traces of limestone 

 being common in it ; whilst on the other hand, the marble near the 

 greenstone is also changed, so that a passage may be traced from 

 one to the other. 



The author concludes by referring to other instances in New 

 South Wales, in which similar phenomena have been produced. He 

 mentions one case in lat. 32° 6' S., and long, abovit 151° E., where, 

 in the neighbourhood of the river Page, veins of marble intersect a 

 lava-like trap ; and another about 16 miles north of Arthursleigh, 

 Avhere a magnificent tunnel in white crystalline marble occurs in 

 the bed of a creek surrounded by basaltic rocks. On a branch of 

 the Abercrombie river, west of the Dividing Range, and about 40 

 miles south of Bathurst, a similar tunnel of gigantic dimensions, 

 nearly 800 feet long and 80 feet high, also passes through a mass 

 of white crystalline marble at the bottom of a ravine in the middl,e 

 of a country of volcanic I'ocks and blocks of snow-white quartz. 



The author hopes to be able, at a future time, to describe 

 these examples more fully ; he alludes to them now to show that 

 there is reason to believe that these connections of limestone, plu- 

 tonic rocks, and quartz dykes, are not without their application to 

 a condition of geological phenomena, to the elucidation of which 

 the banks of the Wollondilly have exhibited a clue. 



3. On the Atherfield Section of the Lower Greensand, in 

 the Isle of Wight. By W. H. Fitton, Esq., M.D., F.R.S. 



[This paper is postponed, not having been received from the 

 author in time for notice in the present number of the Proceedings.] 



