494 



THE PROBLEM OE THE LIZARD ROCKS. 



in the shape of an elongated pocket, a portion of the j&rst layer, 

 as shown in Fig. 8. 



The final stage of such almost incredible compression and 

 distortion is shown in the two last figures. Supposing the dark 

 inner layer to be serpentine, and the outer lighter layer to be 

 banded schist or granulitic rock, we then have an angular frag- 

 ment of the solid rock, as in Fig. 9, entangled in the eruptive 

 serpentine, as Professor Bonney would describe it ; and, finally, 

 we have the identical appearance as described by the same 

 author in his paper on the Lizard rocks — Q.J.Gr.S., vol. xxxiii., 

 p. 894 — of "a tongue of serpentine about \\ foot wide exposed 

 in the schist." 



Fig. 10 represents snch an elongated or sqeezed out "tongue," 

 or, preferably, "pocket;" and in the absence of demonstration 

 of the successive stages, by which it came to attain its present 

 position and shape, it might well be called an igneous rock 

 injected into the banded schist. 



There are innumerable instances of such serpentine pockets 

 all through the Lizard rocks, from the size of a walnut, or the 

 weight of a few ounces to hundreds of tons in weight. 



I have advanced no new theory, but I submit with all due 

 deference to Professor Bonney and other zealous explorers of 

 the Lizard district, that the dynamic theory, as I have now 

 endeavoured to apply it to these rocks, is the only theory hither- 

 to propounded that will meet all the facts of the case. 



There is, of course, a number of collateral questions which 

 I have refrained from touching upon, in order not to com- 

 plicate my main argument. 



