—o 
TRANSACTIONS OF SECTION C. 797 
Syenite was next intruded, generally along the main movement planes such as 
faults, and the junction of the Brand series with the Maplewell series. It has 
been somewhat crushed by the movement, and its main divisional planes agree 
with the cleavage and faulting directions in the country. 
A still later intrusion appears to be the Mount Sorrel granite, which does not 
penetrate into the Forest proper while it is in contact with rocks whose relation 
to the rest of the Forest has not been ascertained with certainty. It is the only 
igneous rock which effects any considerable amount of metamorphism in the clastic 
rocks with which it is in contact. 
As to the age of the rocks we have little to guide us. They are unlikely to 
be later than Cambrian ; they are not at all like the fossiliferous Cambrian rocks 
of Nuneaton ; they do not contain Cambrian fossils, nor do the Nuneaton diorites 
penetrate them. On the other hand, the movement by which they were affected 
came from the direction 8.W. to N.E., whilst Lower Silurian and Cambrian rocks 
are generally, except at Nuneaton, affected by forces which acted at right angles 
to this. 
Professor Lapworth, when with the author in Charnwood, succeeded in finding 
a worm burrow in the slates low down in the Brand series, and Mr. Rhodes has 
since obtained one or two additional examples: these are the first undoubted 
fossils found in Charnwood. 
5. The Geology of Skomer Island. 
By F. T. Howarp, JZA., F.G.S., and E. W. Smatt, I.A., B.Sc., F.GS. 
I. Previous Literature.—De la Beche (in ‘Trans. Geol. Soc.,’ 2nd series, vol. ii.) 
mentions the presence of a ‘quartzose and striped cornean,’ of ‘ bedded greenstone,’ 
and ‘massive compact greenstone.’ Murchison (Silurian system) gives a section 
across part of the island, and indicates the occurrence of Upper Cambrian rocks. 
Rutley and Teall have described the microscopic characters of some of the rocks, 
but none of these authorities gives exact localities, or describes the relationship of 
the different beds. 
II. General Character and Arrangement of the Sedimentary and Igneous 
Rocks.—The general strike of the beds is more or less east and west, with a 
southerly dip. A well-marked ridge of felsitic conglomerate running from the 
west side of the Wick in an east by north direction to the north of Welsh Way 
serves as a convenient base line; beneath it are finer conglomerates, sandstones 
rich in felspar, and red shales; above it finer beds occur to the south, faulted 
against basalt in the Wick, conformably passing beneath the basalt at High Cliff. 
This basalt forms the southern promontory of the island except near the Mewstone, 
where quartz grits occur. Beneath the conglomerate, between the Wick and 
Tom’s House, a very coarse breccia occurs, resting upon and derived from a highly 
siliceous banded and spherulitic felsite, which weathers white and shows spherules 
up to several inches in diameter. This appears to be the felsite described by 
Rutley, and is probably the striped quartzose cornean of De la Beche. In the cove 
west of Tom’s House a basalt appears to pass quite regularly beneath the felsite. 
Massive and thinly bedded basalts follow to the north, but in Pigstone Bay thin 
felsites, grits, and shales are seen, and a conglomerate of basalt and felsite frag- 
ments resting upon an uneven floor of basalt. The section here shows clearly the 
interbedded character of the igneous rocks. North of Bull Hole we meet with 
felsite again, which occupies the northernmost part of the island, including the 
outlying Garland stone. Some bands of ash are seen in the basaltic cliffs between 
the north point of the island and North Castle. Sedimentary grits and shales 
_ occur in North and South Haven, and at the Rye Rocks; they pass beneath a 
basalt which apparently forms all the remaining portion of the Neck. 
IIL. Influence of the Geological Structure on the Physical Featwres,—The two 
marked inlets of North and South Haven, as also the channel separating (at high 
_ water) the Mewstone from the main parts of the island, have been formed by the 
more rapid erosion of the sedimentary strata, and the Wick has been clearly eaten 
out along a line of fault between basalt and sedimentary beds. A curious series of 
