474. TRANSACTIONS OF SECTION C. 
structure’ from those without it, as has been generally done. A key to the 
connection between the ‘buckled’ and ‘ non-buckled’ areas occurs in the ground 
about Shiehallion and to the north (Sheet 55, Scotland). At Shiehallion we have 
the quartzose beds forming the margin of the quartzite, and containing the 
boulder bed and the limestone close by; further north we have the same group 
again. In the first case we have isoclinal folding; in the second, buckled 
folding, or Moine gneiss. 
8. The Heavy Mineral Grains in the Sands of the Scottish 
Carboniferous. By T. O. Boswortu, B.A., B.Sc., F.G.S. 
These observations were made at the commencement of an investigation which 
the author has now no opportunity to carry on. 
The chief heavy grains are :— 
Garnet, which, though in some sands practically absent, in others is in 
such excessive quantity as to almost mask the presence of other grains. 
Zircon, always present, and sometimes the most abundant species. 
Magnetite, always present. 
Tourmaline, always present. 
Rutile, always present, but varies widely in quantity and characters. 
Staurolite, often present, but not plentiful. 
Anatase, occasionally present in noticeable amount, as well-formed plates 
of steel-blue colour. 
Barytes, found in a few cases in large amount. It is probably a cement, 
though well-formed crystal-plates occur. Sandstones containing this 
cement are very hard. I find it in several building-stones. 
Characteristic of all the grains is their angularity. The garnets have the 
dodecahedral cleavage developed out in a remarkable manner, so that the grains 
have elaborate zigzag shapes with innumerable corners and edges. The con- 
trast between these heavy grains and those in desert sands is much more 
marked than in the case of quartz. 
The heavy mineral contents prove the sands to belong to at least two entirely 
different kinds :— 
(a) Sands in which the heavy mineral grains consist mainly or largely of 
garnet. 
(6) Sands in which garnet is absent or scarce. . 
Vertical and Lateral Distribution.—The amount of evidence yet collected 
is only sufficient to be suggestive of the kind of results which may 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.) 
Red Measures. 
o Rutherglen. 
Coal Measures. 
o Cambuslang - «  « above Humph Coal. 
o Chapelhall, Shottsburn. . 24 feet above Lower Drumgray Coal. 
o Chapelhall, Shottsburn. . just above Lower Drumeray Coal 
o Chapelhall, Shottsburn . ; % “ ¥ 
o Fauldhouse Quarry . . above Crofthead 4 feet Coal. 
x Chapelhall, Shottsburn . . below the Coals, faulted, and near Mill- 
stone Grit. 
Millstone Grit. 
x Bilston Burn, near Edinburgh Roslin Grit. 
x Glasgow, Blochairn Quarry . above fireclays. 
x Muirhouse Bore, Lanarkshire depth 30 feet. 
x Muirhouse Bore, Lanarkshire depth 174 fect. 
x Levenseat - «+  «  « above Curdley Ironstone. 
< Balfour Bore, Fife. . . 12 feet above Levenseat Limestone 
horizon. 
o Bilston Burn. . .  . 6 feet above Castle Carey Limestone 
horizon. 
