68 REPORT— 1857. 
eastern extremity Carrick Fell, consist of masses of plutonic and igneous rocks. On 
the southern slopes of these hills there is seen Skiddaw slate, which generally has a 
south dip; and this Skiddaw slate, as it approximates the granite of Skiddaw Forest, 
passes into chiastolite slate, chiastolite rock, and a pseudo-gneiss. On the south side 
of the granite area the same phenomena occur, but on this side hornblende rock and 
actinolite rock also appear. Jn the metamorphic rocks, and likewise in the ordinary 
Skiddaw slates which succeed them in position, the strike of the strata is nearly 
east and west, and the general arrangement of the strata seems to indicate that the 
plutonic and igneous masses of Caldbeck Fells form the axis of the group rather than 
the granite of Skiddaw Forest. With respect to the unaltered rocks of the Skiddaw 
district, these have been referred by Prof. Sedgwick to three groups, black Skiddaw 
slate, grits seen in the masses of Grassmoor, and grey Skiddaw slate containing fossils 
described in the Paleozoic fossils of the Woodwardian Museum. ‘The upper grey 
slates are the deposits which have hitherto afforded organic remains. Last year the 
author obtained traces of worms from the black Skiddaw slate, the lowest member of 
the unaltered series, at Threlkeld, and, from a communication which the author had 
recently from Prof. Sedgwick, it would appear that in these low strata graptolites 
have been lately obtained by Mr. J. Ruthven. With regard to the lithological nature 
of these Skiddaw rocks, it would seem that there is a considerable change according 
to locality. Westward grey slates, with intercalated grits, obtain on the line of the 
strike of the black Skiddaw slates, leading to the inference that coarser beds supply 
the place of the finer black slates on the eastern margin of the area. 
On the Jointing and Dolomitization of the Lower Carboniferous Limestone 
in the Neighbourhood of Cork. By Professor Harkness, F.RS. 
The district round Cork consists of a series of hills and valleys, the former com- 
posed of Devonian, and the latter of limestone belonging to the lower portion of the 
carboniferous series. In the latter are joints having three directions: one, the pre- 
vailing direction being north and south; and of the other two, one is almost horizontal 
and the other oblique. These joints occur in great profusion in most of the limestone 
localities; but in certain spots where the limestone is siliceous and bedded, the joint- 
ings are imperfect and the stratification distinct. Among these limestones there are 
seen in the neighbourhood of Cork dykes of dolomite, and these dykes in jointed lime- 
stone conform to the main perpendicular joints. In the limestone, where the strati- 
fication is distinct, we often find also dolomites; and these agree with the planes of 
stratification. The production of these dolomites appears to be subsequent to the 
deposition of the strata in which they occur, From the observations of Regnault it 
would seem that sea-water (containing sulphate of magnesia) is capable of exerting 
considerable influence on limestone, giving rise to carbonate of magnesia and sulphate 
of lime; and the phenomena exhibited by the district around Cork would lead to the 
inference that sea-water, finding access into rocks by joints, and in some instances 
along the planes of stratification, so produced the dolomitic masses. 
On the Records of a Triassic Shore. By Professor Harkness, PRS. 
The area occupied by the trias strata referred to occurs in the north-west of England 
and the south of Scotland. The deposits which form this series consist of argillaceous 
strata and sandstones, and these beds have their surfaces marked by ripples, which 
have resulted from the action of the wind on shallow water. Ripples of another 
character also occur, and these have been produced by the influence of small rills 
traversing a muddy shore. Tracks which have originated from the wanderings of 
crustaceans likewise make their appearance on the surface of the sandstones, and with 
these are found associated the sinuous tracks of annelids, as well as the pitted hollows 
which form the entrances into the burrows of these animals. Pseudomorphic crystals 
of salt are also exhibited in the state of small pyramidal elevations on the under sides 
of the sandstones, affording evidence of natural salt-pans on this Triassic shore. Small 
pittings mark, in many instances, the faces of the sandstones, and the surfaces repo- 
sing upon these pitted faces manifest little dome-like elevations. These have arisen 
from the effect of rain-drops, in most instances of a small size, resulting from fine 
