46 Transactions. 
Far more extensive than the above are the marine sediments of the 
Rolling Downs formation in Australia, concerning which ideas at present 
are somewhat uncertain. As recently as in 1914 Professor David, in 
summarizing their occurrence, declared them to be a Lower Cretaceous 
series of glauconitic sands and clays, almost wholly of marine origin, 
passing conformably downwards into fresh-water Jurassic rocks, and 
Ke pitt 
m Hte 
#7 
, 
SUR PERIODS 
^ 
` 
lbs аду же чань О ||| LOWER & MIDDLE 
| ШЫН ORR SF | all C A 
| 
“ 
à 
D 
D 
E ^E 
IH : 
Li ct 
INE Ae 
| 
| 
Lo єл» ОА; 
ШШ Late Jurase to Mid. Crets Deep оо HH Exposures af sediment of origin indicated 
| т prs 
pe | | he | 
1*9. 
a" "Tr; |, Based with modification 
| on Or Walkom's chart 
i 
ẹ 
[E] Land ' á go ES nari | 
[SS inao: Pacific Middle Cretaceous Sea фа l 
E Lote Juras: to Mid. Crets Rolling Downs Sea RE { 
see 
| 
~ -li 
= Juras* to Basal Cret? Tethyan Sea 
Regression in Early Cretaceous times 
ti 
Etheridge (1902), after the examination of many cores obtained from 
artesian wells, felt that “ the time is not far distant when we shall be in a 
k up our continental Cretaceous system into a number 
of well-defined life-zones." ^ Gürich (1901) had previously discussed the 
age of a collection from these beds near Wileannia, and had referred them 
to the Jurassic on apparently inadequate evidence. Particular interest 
attaches, however, to the age of the Maryborough plant-bearing marine 
bed, which at first was classed with the ^ Desert Sandstones " as Upper 
