144 THE PROGRESS OF GEOLOGICAL RESEARCH IN TASMANIA, 



system with the Pre-Cambrians of the Australian mainland 

 is a step which can only follow such an investigation. 



(b). The relationship of the Dikelccephalus sandstone 

 series to the other rock systems still remains to be deter- 

 mined. It seems highly desirable that the series should be 

 thoroughly searched for a complete suite of fossils, and 

 these examined in detail in order to definitely establish, or 

 otherwise, the Cambrian age determination. 



(c). The rock system now termed Cambro-Ordovician 

 requires more exact age determination. Particularly should 

 search be directed in the sedimentary members for fossils 

 which so far have escaped observation. 



(d). The stratigraphic relationship between the Dun- 

 das slates, the Balfour slates and sandstones, and the Math- 

 inna slates and sandstones yet remains to be determined. 



(e). The structural geology of the whole of the Cambro- 

 Ordovician system must be worked out on the lines already 

 accomplished in the Read-Rosebery district. In this con- 

 nection it will be important to deduce from the strike and 

 dip of the planes of schistosity of the schistose members of 

 this system the position of the drag folds, and from these 

 to determine the location of the axes and dimensions of the 

 major folds. 



(f). The petrology of the porphyroid igneous complex 

 must be studied in greater detail, and the effusive and pyro- 

 clastic members distinguished from the intrusive and plu- 

 tonic. With the solution of the structural problem will then 

 come the opportunity of finally determining the order of suc- 

 cession within the petrogenic cycle. Incidental to this is 

 the relationship between the Read-Rosebery and Mt. Lyell 

 schists, which are probably different facies of the same geo- 

 logic horizon. 



(g). The sapropelic coals of the Permo-Carboniferous 

 system are deserving of minute investigation, as they pro- 

 mise to throw much light on the natural history of coal. The 

 exact details of the transition from these coal beds to the 

 Tasmanite shale marine facies of the same horizon still re- 

 main to be determined, 



(h). The stratigraphy and more definite age determina- 

 tion of our Trias-Jura system both demand attention. Par- 

 ticularly a detailed study of our Trias-Jura flora and com- 

 parison with that of the mainland must be undertaken. It 

 is important also to determine whether the break between 



