PROCEEDINGS OF SECTION C. 187 



This folding in all probability took place at the latter end of the 

 Lower Cretaceous period, for one invariably finds in Queensland an 

 unconformity between the RolUng Downs and Desert Sandstone, 

 the result no doubt of earth movements to which Queensland was 

 subjected at the end of the Lower Cretaceous period. 



There is very little faulting in the area and an even greater 

 scarcity of igneous rocks. 



Relationship op the Lower Cretaceous Coal Measures to the 

 BuRRUM Formation. 



This relationship is a particularly interesting one, and the foUowiiig 

 question naturally arises : — " Are the lower cretaceous coal measures 

 the same as those of the Burrum coal-field ? " 



Dunstan* believes that they are the same, and assigns an age 

 corresponding to an upper division of the RolUng Downs formation for 

 them. 



The field evidence strongly supports this belief for the area has been 

 shown to have been subjected to folding movements resulting in anti- 

 clines and synclines and the Burrum coal-field has been shown* to 

 occupy a synclinal area with cojiformably underlying marine rocks 

 of Lower Cretaceous age. 



Unfortunately recognisable plant remairs from the Woody Island 

 ooal-measures to compare with the Burrum plant remains are apparently 

 unobtainable, so that one must rely on field relationships. 



Jackf states " The relation of the Maryborough beds to the 

 Burrum beds, although obscure, is believed to be that the former rest 

 unfonformably on the latter, and that a fault (which, however, is not 

 seen) must account for the fact that the lowest of the Maryborough 

 beds after dipping does not rise on the other side. Their apparent 

 oonformability to the Burrum beds must be deceptive " 



Also in Plate 46, Fig. 3, he gives a sketch section drawn up by 

 W. H. Rands, showing his interpretation of how the fault must come 

 in. 



However, the Maryborough beds do come up on the other side 

 and the conformability is not deceptive as believed by Jack, for the 

 sequence here is what one obtains in other places in the area, and, 

 moreover, the general strike of the marine beds is the same all through 

 in the various outcrops. 



The evidence of a Lower Cretaceous age for the Burrum formation 

 is then fairly conclusive. Jack places the Burrum formation strati- 

 graphically below the Ipswich formation, but Cameron J has shown 

 reasons which are supported by Jensen's observations at Point Ark- 

 wright why one should consider the Burrum beds and the Ipswich 

 beds of identical age. 



• Duastan. Qld. Govt. Mining Journal, 16th I>3cember, 1912. 



t Jack and Etheridga. Goel. and Pal. of Qld. and New Guinea, p. 300. 



t West Moreton Gold-fleld3 2nd Report. QJd., 1907, p. 12. 



