CARBONIFEROUS AND PERMO-CARBONIFEROUS ROCKS, N.S.W. 273 



temporary forward movement of the ice front. Delicate, 

 but well-preserved, annelid tracks are found on the bedding 

 planes of some of the varve shales. 



Reference to the sections at Paterson and Seaham (Plate 

 XIX) will show that there are two series of these varve 

 shales with an aggregate thickness in each locality of about 

 200 feet; the thicknesses given are not absolutely accurate 

 as the junctions with the associated strata were not always 

 too clear. These varve shales form a very persistent horizon 

 and have been observed at intervals from the Raymond 

 Terrace Road to Gresford, a distance of over 20 miles. 

 In every place where they have been found they are 

 associated with tillites and always display the same details 

 of character and structure. 



The White Tuffs. — These are white to light-yellow 

 coloured rocks, which in the hand specimen look like fine- 

 grained tuffs of an acidic composition, but it is quite possible 

 that they may be deposits of glacial sandy material deposited 

 at times when the conditions were not favourable for the 

 deposition of the varve shales, as they are not unlike the 

 coarser layers of the varve shales. These rocks need 

 further investigation. 



The Grey Tuffaceous Mudstones. — These rocks make 

 very poor outcrops and their true nature is difficult to 

 determine; they resemble fairly closely the groundmass of 

 some of the tillites, and apparently contain no fossils. They 

 are included here with the glacial beds, but without any 

 very definite opinion that they are directly of glacial 

 origin. 



The Geological Age of the Glacial Beds. — These beds 

 have by previous writers been referred to the Permo- 

 Oarboniferous System and placed at the base of the Lower 

 Marine Series. They are here included with the Kuttung 

 Series for the following reasons: — 



R— December 3, 1919. 



