Thorium in Sedimentary Rod's. 



127 



ABLE. 



1. 



2. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 

 14. 

 15. 

 16. 

 17. 

 18. 

 19. 

 20. 

 21. 

 22. 

 23. 

 24. 

 25. 

 26. 

 27. 

 28. 

 29. 

 30. 

 31. 

 32. 

 33. 

 31. 



(gr 



Littorina Limestone (Pleistocene). Rhein Hesse. (45) 



Nummulite Limestone, loc. ? (50) 



Marsupites Chalk, loc? (32) 



Upper Chalk. Co. Antrim. (50) 



Lower Chalk. Isle of Wight. (34) 



Earthy Limestone (Upper Cretaceous). Were, Westphalia. (30) 



Doloraitic Flagstone (Portlandian). Embeckhausen, Hannover. (30) less than 



Oolite. Isle of Portland, Dorset. (50) less than 



Lithographic Slate (Kimmeridgian). Solenhofeu, Bavaria. (30) less than 



TlIOKILWf. 



per grm.XlO— 5). 



013 



less than 

 less than 

 less than 



(40) 



Limestone (Jura). Hohensteiu, Saxony. (30) ... 

 Limestone (Jura). Schnaitheim, LTlm. (30) 



Eed Marble. Italy. (30) 



Limestone (Malm). Untergletcher, Grindelwald. 



Limestone (Dogger). Sandfirn, Todi. (40) 



White Marble (Trias). Carrara, Italy. (30) 



Musohelkalk. Heidelberg. (50) 



Limestone (Zechstein). Tettenborn, Harcz. (30) 



Limestone (Upper Carboniferous). Co. Kildare. (30) 



Limestone (Carboniferous). Armagh, Ireland. (22 - 5) 



Oolite (Carboniferous). Ballina, Co. Mayo. (50) 



Limestone (Carboniferous). Nuttlar, Westphalia. (30) 



Limestone (Carboniferous). Dusseldorf. (30) 



Limestone (Lower Carboniferous). Co. Kildare. (30) 



Lower Limestone Shale. Co. Kildare. (30) 



Grey Marble (Upper Devonian). Namur, Belgium. (30) .. 



Black Marble (Devonian). Shuppach, Nassau. (30) 



Dolomite (Devonian). Gerolstein, Eifel. (30) 



Fa vosites Limestone (Devonian). Torquay, Devon. (30) .. 



Coral Limestone (Upper Silurian). Aymestry. (35) 



Porites Limestone (Middle Silurian). Wenlock. (35) 



White Marble (Lower Silurian). Boda, Norway. (30) 



Cheirurus Limestone (Ordovician). Chair of Kildare. (40) 



White Marble (Archasan). Pentelicon, Greece. (30) 



Dolomite. Fichtel Erzgebirge ; Sayda, Saxony. (30) 



less than 

 less than 

 less than 

 less than 

 less than 

 less than 

 less than 

 less than 

 less than 

 less than 

 less than 

 less than 

 less than 



less than 

 less than 



less than 

 less than 

 less than 

 less than 



less than 

 less than 



In the case of two rocks dealt with (Nos. 6 and 24) there 

 were at once very considerable insoluble residues, and a 

 thorium content greater than was generally indicated. It 

 seemed of interest to find if the thorium was in these cases 

 in the soluble or in the insoluble part of the rock. The 

 soluble part of 42 grams of No. 6 was tested separately and 

 found to contain 5*3 x 10 -5 gram thorium. The total thorium 

 in 42 gram is 9'lx 10~ 5 . Hence there is no special concen- 

 tration of the thorium in the insoluble part, which in this 

 case was found to be very nearly 40 per cent, by weight of 

 the rock. In the case of No. 24 the soluble part of 50 grams 



0-08 

 0-06 

 0-03 



0-05 

 0-22 

 0-05 

 0'0S 



0-05 

 0-05 

 0-05 

 0-05 



0-O4 



0-04 



0-05 

 0-03 

 0-05 

 0-05 

 0-10 

 0-03 

 0-05 

 005 

 014 

 0-33 

 0-05 

 0-05 

 0-16 

 0-05 

 0-05 

 0-05 

 0-05 

 0-05 

 0-05 

 0-05 



