516 



Notices of Memoirs — British Association — 



so that the grains have elaborate zigzag shapes with innumerable corners 

 and edges. The contrast between these heavy grains and those in 

 desert sands is much more marked than in the case of c^uartz. 



Tlie heavy mineral contents prove the sands to belong to at least two 

 entirely different kinds : — 



(ff) Sands in which the heavy mineral grains consist mainly or 

 largely of garnets. 



(6) Sands in which garnet is absent or scarce. 



Vertical and Lateral Distribution. — The amount of evidence yet 

 collected is onlj'^ sufficient to be suggestive of the kind of results which 

 maj^ be obtained. 



In the following list o denotes garnetiferous, x denotes non- 

 garnetiferous. (Measurements in bore sections are actual, and are not 

 corrected for inclined strata.) 



Mecl Measures. 



o Eutherglen. 



Coal-measures. 



o Cambuslang 

 o Chaijelhall, Shottsburn 

 o Chapelhall, Shottsburn 

 o Chapelhall, Shottsburn 

 o Fauldhouse Quarry 

 X Chapelhall, Shottsburn 



Millstone Grit. 



X Bilston Burn, near Edinburgh 



X Glasgow, Blochalrn Quarry 



X Muirhouse Bore, Lanarkshire 



X Muirhouse Bore, Lanarkshire 



X Levenseat .... 



X Balfour Bore, Fife 



o Bilston Burn 

 Carboniferous Limestone Series. 



o Balfour Bore, Fife 



o Bilston Burn 



o Balfour Bore 



X Giffnock .... 



o Balfour Bore 



o Bilston Burn ... 



o Bishopbriggs, Hunters' Hill 



X Kirkintilloch 



o Linlithgow .... 



X Bilston Burn 



X Balfour Bore 



o Balfour Bore 



X Balfour Bore 



o Bilston Burn 



X Bilston Burn 

 Calciferons. 



X Milngavie .... 



Burntisland, Grange Quarry 

 Hailes Quarry. 

 Craigleith. 



above Humph Coal. 



21 feet above Lower Drunigray Coal. 



just above Lower Drumgray Coal. 



above Crofthead 4 feet Coal, 

 below the Coals, faulted, and near Millstone 

 Grit. 



Roslin Grit. 



above fireclays. 



depth 30 feet. 



depth 174 feet. 



above Curdley Ironstone. 



12 feet above Levenseat Limestone horizon. 



6 feet above Castle Carey Limestone horizon. 



36 

 100 

 360 

 270 

 150 



12 



40 



200 



540 



798 



1,242 



1,374 



5 



10 



feet below Calmy Limestone horizon, 

 feet above Index Limestone. 



just ,, ,, 



feet below Index Limestone. 



feet below Hosie Limehouse horizon, 

 feet above North Greens Limestone. 



above the Traps and below Hurlet Lime- 

 stone, 

 about Burdiehouse horizon. 



Conclusions and Suggestions. — The sands containing such an extra- 

 ordinary quantity of angular garnet have been derived from the 

 Highland schists to the north and north-west of the ba5in, whilst the 

 sands devoid of garnet are likely to have come from the north-east, east, 

 or south. 



It may be possible by a study of the heavy mineral grains and of 

 the current-bedding, and the thickening and thinning of the beds, to 

 subdivide the whole of the Carboniferous accumulation into a number 

 of great lens-shaped or wedge-shaped bodies of sediment, which have 

 been introduced from various directions and are interdigitated in 

 a complex manner. These great lenticles might be expressible on maps, 

 and might be helpful in explaining the lateral changes and the dis- 

 tribution of the coals. 



