90 PROCEEDINGS OF THE ROYAL SOCIETY OF QUEENSLAND. 
slickensiding must be the result of earth movements that post-dated the 
upper division basalt, and accordingly of late Tertiary age. Moreover, 
with reference to the weathering, it seems feasible from its very position 
that the basalt may have been extensively weathered by the action of salt 
water before the recent uplift. This suggestion seems to receive further 
support from the presence again of this very slickensided decomposed 
basalt in the cliff banks of Scott’s Point on the Redcliffe Peninsula, 
several miles to the N.N.E. Another possible explanation, however, is 
that slickensiding was brought about by slumping of the very weathered 
basalt or clay following supersaturation. 
As opposed to this, the basalt which caps Bald Hills is normally 
weathered and shows no evidence of slickensiding. In fact, quite fresh 
specimens can be obtained from the central portion of the weathered 
spheroids in the road cuttings. This fresh basalt is greenish-black in 
colour, and has a specific gravity of 2-81. Microscopic examination has 
shown it to be made up predominantly of titaniferous augite and 
plagioclase (acid labradorite), together with olivine altering in part to 
iddingsite, and magnetite. 
Apart from the basalt at Bald Hills which has previously been 
mapped, the writer has noticed weathered basalt outcropping in the road 
bank along Ridley road between Beams and Roghan road. As this is 
approximately on the same level as Bald Hills, and is only one mile S. 
of the most southerly exposure of Bald Hills basalt, it seems likely that 
this patch of basalt in the Ridley-Roghan road area was formerly- 
connected with it. 
III. THE EASTERN AND NORTH-EASTERN ST R ATI- 
GRAPHICAL RELATIONSHIP OF THE SERIES. 
On certain lithological resemblances and the presence of inclusions 
of shale containing plant markings, it was formerly thought by the 
writer that the sandstones recently exposed in excavations near the 
Hornibrook Highway at Brighton, and those outcropping on the 
southern side of Bald Hills Creek, near the corner of Hall and Lascelles 
streets, might represent an eastern extension of the Petrie Series 
towards the coast. Palaeontological evidence has, however, disproved 
this assumption. A recognisable impression of Cladophlebis australis 
has been discovered in the sandy shales near Bald Hills Creek, and slides 
made of the fossil wood, which is quite abundant in one sandstone horizon 
in the excavated cuttings at the Brighton locality, have shown the age 
to be Upper Triassic. All the fossil wood specimens collected, probably 
representing seven or eight separate trunks, have proved to be coniferous. 
They show no sign of water-rounded surfaces, and their relative abund- 
ance also tends to confirm their contemporaneity with the sandstone. 
Radial and transverse sections from two of these specimens have shown 
them to be identical with DadOxylon ( Araucarioxylon ) australe 
originally described by Crie (1889, p. 5) from beds of Upper Carnic (i.e., 
Upper Lower Keuper) age at Teremba, New Caledonia. Microscopic 
study of thin sections made from another specimen has shown it to be 
Dadoxylan ( Araucarioxylon ) rajmahalense described by Sahni (1931, 
p. 69) from the base of the Rajmahal stage (Upper Gondwana) of India. 
The Rajmahal stage is at the very base of the Jurassic in India. It 
might be mentioned that Fisher ( 1931, p. 44) has recorded fossil wood 
“comparing very closely with Dadoxylan ( Araucarioxylon ) rajmahal- 
ense Sahni” from beds with a typical Upper Esk facies at Aspley, some 
