Name of rock or mineral. Locality. Character.
Volume of gas ! per volume of rock. 1 1 Composition in 100 volumes. j c o 2. i H2) * c. 1 . Rocks o f Tertiary Age. 1 i fltVm ............................. Plutonic, acid .. .. i 1-6 11 *5 | 88-5 vxranite l . .................. ..................... 2 . .............. 2-8 31 0 69 0 >3 .............................................................. Salen, Mull........ .. ” * ” _ 1-3 34*7 65 3 J) ....................* * *................ *........ Gabbro........................ . ................ L. Coruisk, Skye ............ ,, basic,. .. ! 3 *5 21 *6 78-4 A ntvim . ..................................... 8*0 1 32*0 68-0 RocJcs of Palaeozoic Age. Quarlzifft t , - .................. Durness (Sutherland).. . . . . . . Aqueous, altered .. 2*2 14*3 | 85-7 G-abbro..................... . . ........................... L izard.............. ............... .... Plutonic, basic.. .. 6*4 trace 1 100-0 Granite. ... Petevhefl.fi.................................. „ acid. . . . 2'6 24*8 75-2 .. . . . . t Onvnwflll..................................... ! .... 4*3 i 8*8 91-2 RocJcs o f UnJcnotvn Age (mostly Archaean). Granite.................................................... . [ Near Dublin.. ...........................| Plutonic, acid........ 1 5*0 9*4 90-6 Ardshiel 6*9 79*5 20-5 Greisen.. ,. .. Altenburg (Saxony)................ i ,, altered.. 1*8 13 *6 86 *4 Granulite......... ............................ . Central India. ...................... •, 2*6 j 48*7 5 1 3 1 Quartz schist. ,. Castlewellan (co. Down).. . . . . Metamorphic........ 2*8 23 *0 77-0 1 ITuclisite schist 4*2 20 *8 79-2 Corundum ro c k .................... .................... .. Pipra, S. Bewail, In dia..........] 3*5 26*0 74-0 ! Pyroxene gneiss.......... t t......... Pom bra (Ceylon)...................... 7*3 84*4 15 6 1 Gneiss with corundum.................................... Seringapatam........................ » ..... 17*8 18*0 82 -0
- , „ garnets and graphite.. . . . . .. Doloswella (Ceylon)................ ,, ..... 4*5 11*0 89'0
1 Himalayas (Nanga Parbut)... „ . • • • • 7*2 11 *5 88 *6 Recent Lava. | Vesuvius, 1760 ! ..........................| • • 0*65 !72'0 \28-0 Minerals. Graphite......................t .. J Cey 1 o n .......... 7*5 48*0 5 2 0 Quartz matrix of same . .. 1 *2 44*5 55 5 j Beryl.......................... 1 Glen Cullen (co. Wicklow) .... 6*7 6*0 94 0 Tinstone .................... ' Straits Settlements ................. 1 3 45 *4 54-6
