390 
PROFESSOR F. D. ADAMS AND DR. J. T. NICOLSON 
39. Marble. Lot 14, Range III., Township of Lake, Canada. 
40. Limestone. Lot 1, Range I., Township of Lake, Canada. 
41. ,, Lot 16, Range XII., Township of Wollaston, Canada. 
42. Marble. Lot 12, Range V., Township of Burleigh, Canada. 
Limestones and Marbles showing the Structures of the Artificially Deformed 
Marbles. 
1 . Marble. Troviken, Norway. —This is a beautiful white marble from the contact 
zone in the -Velfjorden. It is cited by Vogt as an example of a marble showing 
cataclastic structure, and is figured in his paper on marble before referred to. It is 
composed of large irregular-shaped individuals or fragments of calcite, embedded in a 
mass of smaller grains. In the hard specimens the cleavage surfaces of the large indi¬ 
viduals can often be observed to be bent or curved in a striking manner. Under the 
microscope the large grains are seen to be in the act of breaking down into smaller 
grains. Almost every grain is twinned, and the great majority show strain shadows, 
which are often very marked. The structure is cataclastic, the smaller grains having 
been derived from the breaking down of larger ones, some of which survive in part as 
the remnants. There has not, however, been that rolling out and flattening of the 
grains seen in No. 13. The rock is stated by Vogt to owe its coarsely crystalline 
character to contact metamorphism, and its secondary cataclastic structure to subse¬ 
quent dynamic action. 
2. Marble. Tyrol, Austria. —A medium grained white saccharoidal marble of 
Liassic age, the precise locality of which it has been impossible to ascertain. The 
rock has undergone incipient deformation, and under the microscope presents an 
appearance similar to that seen in those artificially deformed marbles where the 
motion is due to twinning and gliding. The individuals of calcite with scarcely a 
single exception are twinned, often showing a double set of twin lines crossing one 
another. Many of the grains are bent or twisted along certain lines marked by 
deep strain shadows. The individual grains are approximately uniform in size and 
usually come together along smooth sweeping lines. 
3. Marble. Alte Kirke, Anclermatt , Switzerland.- —This well-known marble, 
believed to be of Jurassic age, and which has, according to Heim, been reduced to 
one-tenth of its original thickness by the enormous pressure to which it has been 
subjected during the folding of the Alps, is distinctly foliated, consisting of rude 
bands of larger and smaller grains of calcite. The foliation is chiefly due to the 
flattening of the calcite grains. Almost every grain is twinned and many show 
strain shadows. The sections also show little streaks or areas of much more finely 
crystalline calcite, containing a good deal of dark colouring matter, apparently a 
carbonaceous pigment. These are quite different in structure from the rest of the 
rock, and evidently represent the last remains of the original fine-grain limestone, from 
