AUSTRALIAN GLACIATIONS 211 
In the majority of cases the glacial deposits of Tasmania (of 
this age) appear to have been laid down under the agency of land- 
ice, but in a few localities, as in the fossiliferous mudstones of the 
Derwent, near Hobart, sporadic bowlders occur mixed with a 
marine fauna in a way that is suggestive of floating ice. 
NEW SOUTH WALES 
The Permo-Carboniferous rocks of New South Wales occupy 
an area of about 26,000 square miles and are by far the most 
important development of rocks of this age in Australasia. They 
owe their existence to a great monoclinal fold which, on the western 
side, formed the Blue Mountains; and on the eastern, the great 
geosyncline that supplied the conditions for the building up of a 
vast coal field. This basin, including the Triassic beds which con- 
stitute the upper portion of the basin, is about 17,000 feet in thick- 
ness. 
The Permo-Carboniferous series consist of the oleae main 
divisions: 
1. Upper, or Newcastle Coal Measures (fresh-water beds with 
BroduchivecodlMabout mej. ace nent is holes ae nee 1,500 feet thick 
2. Dempsey Series (fresh-water without productive coal), 
I BXOUIE eae esate & eGR Ts os SRR SRLS) ORR oP 2,000 “ : 
3. Middle or Tomago Coal Measures (raductive)s abOUtA RT ILOCO! a 
4. Upper Marine Series (includes the Branxton glacial hed), 
NOG UCR ree ene er mers wenn UU ution ty coche 6,400. 0 
Em cower or Greta Coal Measure, about.....0 0.0.2.2... DOOM a ain 
6. Lower Marine Series (including several horizons of glacial 
GEUS) ea OU esis rarer entre ot ates te HAS te NL od ae iypsletey hae 
The flora of the fresh-water beds is especially characterized by 
Glossopteris, Noeggerathiopsis, Gangamopteris, Sphenopteris, etc., 
while the marine beds yield an abundant’ fauna of a distinctly 
Carboniferous facies, with such genera as Lithostrotion, Cyatho- 
phyllum, Zaphrentis, Favosites, Productus, Chonetes, Orthis, Spiri- 
HICTZ CLC. 
Glacial erratics are met with at various horizons both in the 
Lower Marine series and the Upper Marine series, and have been 
found in many localities. The two main horizons for glacial 
