BY A. X. LEWIS. M.C.. LL.I!. JO 



Geological Survey in 1914 shows the eastern boundary of 

 the Pre-Cambrians here from 3 to 5 miles too far east. 



(b) Early Palaeozoic. 



Recks of this age predominate in the area. They con- 

 sist of massive and extremely hard quartzites with occasional 

 beds of slate and conglomerates. The age of these beds, 

 which occur considerably in south-west Tasmania, is not 

 definitely fixed. They are to be seen overlying the Prote- 

 rozoic (Twelvetrees, 1908) and at Tim Shea, the Needles, 

 and the Thumbs they underlie beds of West Coast Con- 

 glomerate, now known to be the base of the Silurian (G. A. 

 Waller 1904, Loftus Hills 1921) which cap these peaks. 

 Beds of limestone occur south-west of Mt. Mueller, and 

 these can be seen to be overlying the quartzites. Mr. W. S. 

 Dun considers these limestones (Gordon River series) from 

 palaeontological evidence to be undoubtedly members of the 

 Silurian system, and these beds of quartzite, allotted by 

 R. M. Johnston, Twelvetrees, Mcintosh Reid, and others, to 

 the Cambrian, appear certainly to be Pre-Silurian. For 

 the present Cambi'o-Ordovician appears the most correct 

 classification. 



On the east side of the Huon every eminence protruding 

 from the glacial plain consists of quartzites of this age, 

 always inclined at a high angle and in massive layers 

 separated at intervals by thin layers of more flaky rock. 

 Time did not permit of the working out of the details of 

 the stratigraphy of these beds, but almost every outcrop 

 showed a different angle of dip. The colour is generally 

 white, but often tinged with pink. The cliffs to the north- 

 west of the more northerly of the two western spurs of Mt. 

 Anne show a beautiful salmon-tinted shade visible from 

 some distance. On the western side of Mt. Anne the quartzite 

 is dipping at an angle of about 50 degrees in a direction 

 about 45 degrees W. of N. The quartzite is traversed in 

 all directions by veins of white quartz, often over an inch 

 in thickness. 



The quartzite extends under the diabase cap of Mt. 

 Anne, which is about 1,500 feet in thickness. Perched on 

 the top of the diabase is another small layer of quartzite. 

 This will be commented on later when dealing with the dia- 

 base. The quartzite can be seen emerging from under the 

 diabase on every side of the mountain, and is continued 

 southward at least as far as the valley of the Huon, com- 

 prising the plateau mentioned as lying south and south-east 



