308 



THE GEOLOGIST. 



granite, compared with the sedimentary rocks in New South Wales, being 

 as 3 to 1, while in Tasmania they are as 7 to 1. Of rocks having more 

 than 60 per cent, of Hme as compared to rocks with less, the proportion in 

 New South Wales is 4* 1 to 1 ; in Tasmania the case is reversed, the pro- 

 portion 1 to 3. Count Strzelecki attributes this difference to volcanic 

 agencies, which have beenmore prevalent in Tasmania than in the Australian 

 continent. Some specimens of serpentine veined with asbestos, from the 

 Asbestos Hills, show themselves susceptible of a high degree of polish. 

 Black and white marbles from the Florentine Valley and from Chudlegh 

 are shown ; and of building stones, specimens from numerous quarries are 

 exhibited by Mr. Calder ; there are also some grindstones of large size and 

 fine quality, and some smaller ones said to be eminently suitable for glass- 

 cutting. The beautiful marbles exhibited have hitherto only been used 

 for making lime, but properly polished they will be well suited for internal 

 architectural decorations. Topazes are exhibited from Flinders Island. 



Pembrokeshiee Antheacite. — From Broadmoor Colliery, near Tenby, 

 and Landshipping Colliery, Haverford West (South Wales). Analysis : — 

 Carbon 93. Hydrogen 3-08. Azote '54. Sulphur '68. Oxygen 1-67. 

 Ash 1"03. The following is the order of the strata : — 



Bkoadmooe. 



1, Yellow magnesian sandstone, or lime- 



stone. 



2. "Kock Vein,", about 3 ft. of good 



anthracite. 

 8. Dunstone (Fire Clay). 



4. Argillaceous and arenaceoas rock with 



nodules of ironstone. 



5. "Low Vein," 1 ft. 8 in. of inferior 



culm. 



6. Fire Clay. 



7. Hard siliceous rock with a few argil- 



laceous bands. 



8. Argillaceous slate with bands of iron- 



stone. 



9. "Timber Vein," varying from 7 



to 10 feet thick.* 

 10. Fire Clay. 



Landshipping. 



1. Argillaceous arenaceous shales with 



abundant nodules of ironstone. 



2. "Bright Vein," about 4 ft. 6 in. of 



culm, of a clear bright aspect. 

 8. "Dunstone," or Fire Clay. 



4. Yellow magnesian sandstone, with a 



few bands of shales. 



5. "Rock Vein," about 2 ft. 6 in. of 



good stone coal. 



6. Dunstone (Fire Clay). 



7. Dark argillaceous slate, or slaty earth. 



8. "Timber Vein," an anthracite 

 seam varying from 6 to 8 feet. 



9. Dunstone (Fire Clay). 



10. " Little Vein," 1 ft. 8 in. of culm. 



11. Dunstone (Fire Clay). 



12. Compact argillaceous rock with some 



bands of iron-ore. 



13. Hard siliceous and calcareous rock 



about 2 feet. 



14. " North Vein," 1 feet 3 inches to 1 ft. 



6 in. of anthracite. 



There are several small seams of coal below the "Timber Vein," the 

 largest and most important of which are " the Lower Level ' ( = 1 ft. 8 in.) 

 and the Kilgctty ( = 1 ft. 8 in. to 4 feet), considered the best anthracite. 

 The former is about 70 fathoms below the " Timber Vein," and the latter 



* The beds printed in black letter are those of which samples are in the Exhibition. 



