W. M. Hutchings—Altered Igneous Rocks, Tintagel. 57° 
I may here mention that it was a section of this schist which Mr. 
Teall saw, together with a piece of the epidiorite, though from 
another outcrop. His suggestion that they might prove to be directly 
connected in derivation was made at the time without the slightest 
knowledge of the actual field-relationships, but has proved to be 
perfectly correct. 
We have here, then, a very interesting case of the passage of a 
massive epidiorite into a perfect chlorite-schist; and doubtless a 
further series of specimens, taken at shorter intervals, would prove 
very instructive. ; 
This sheet is of but moderate thickness—a few feet only. It 
appears to be separated from a very much thicker sheet, which 
underlies it, by a bed of shale or slate, the contact with which is 
well seen at the lower part of the cliff. Concerning the question as 
to whether this and other sheets of igneous material to which I 
shall allude are intrusive or contemporaneous, it seems that De la 
Beche regarded them all as being the latter. So far as my own 
observation goes, I should incline to hold the same opinion, at least. 
as concerns those exposures where a considerable extent of the upper 
and lower contacts with the slates, etc., is plainly visible. But I 
would express this opinion with much diffidence, in view of the 
great. disturbances which have everywhere taken place in this 
district, and the great amount of alteration the rocks have undergone. 
The sheet just considered appears to follow the curve of the coast 
and to wind round towards Barras Nose and the Castle Cove; but 
much of the intervening shore is inaccessible and examination could 
not be made. About two-thirds of the way towards Barras Nose 
there is another outcrop of chloritic epidiorite, intermediate in nature 
between No. 1 and No. 2. 
In the Castle Cove is exposed a sheet of rock which I am inclined 
to think is very likely a continuation of the one just described, though 
it is not possible to trace the connection to the point of proof. The 
nature of the rock is here different in many respects, but nothing is 
more striking than the considerable and often rapid changes of 
character which the igneous rocks of this district show. The sheet 
I allude to is seen on both sides of the Cove. On the left it is 
inaccessible in the cliffs of “Tintagel Head,” but on the right it 
may be freely examined. Jt overlies a bed of black shale, with 
which its contact is sharply defined ;—the same bed of shale which, 
curving steeply upwards from the Cove, passes right under a portion 
of the “Mainland,” part of the Castle. So that originally this sheet 
of igneous rock swept up over the country inland, but is now wholly 
removed by denudation. As seen at the right-hand side of the cove, 
where the fishing-boat is hung on davits, it is a hard, grey, rather 
fine-grained, moderately-foliated rock. It is a good deal jointed 
and cracked, and all these cracks are filled with quartz. This is the 
only case in the district of an igneous rock being veined with quartz 
instead of the usual calcite. 
The microscope shows it to consist mainly of felspar and chlorite, 
without any trace of original ferro-magnesian mineral or of secondary 
