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May it not be possible, that all we want to complete the remaining members of the series, is simply to be able to carry out our section into the Moray Frith ?
Such a hypothesis receives confirmation from the fact that in the neighbourhood of Elgin are beds containing wealden fossils; which, says Nicol, we are led to suspect are not original formations, but fragments of more extensive beds, perhaps drifted to this place. The drifted clay, containing lias fossils at Blackpots, may also indicate a formation beneath the waters of the bay. By referring to the Geological Map of England, it will be seen that the greensand accompanies the chalk on the west, and on the east, the lias, &c., to the shore of the channel. Our patch of it at Cruden might form part of the termination of a similar strip, unless it too may be accounted for in the same way as the Moray wealdens, by supposing it a drifted fragment from the north.
May we then fairly infer that at one period the space now occupied by the Moray Frith contained a perfect sequence of the Secondary formations? That first, the soft chalk strata suffered denudation, by the ordinary action of north-easterly gales, and that the roll of the German Ocean piled up its water-worn flint boulders along its successive ancient shores; and that the wealdens and oolites of Elgin, and the lias of Blackpots, followed in the same course ?
That part of this theory applicable to the lias of Blackpots, Mr. Miller states thus, in his description of that deposit : “ There had probably existed to the west or north-west of the deposit, perhaps in the midst of the open bay, formed, by the promontory on which it rests (for the small proportion of other than liassic materials which it contains seems to show that it could be derived from no great distance), an out-lier of the lower lias. The icebergs of the cold glacial period, propelled along the submerged land by some arctic current, or caught up by the gulf-stream, gradually grated it down, as a mason's labourer grates down the surface of the sandstone slab he is engaged in polishing; and the comminuted debris, borne eastward by the current, was cast down here."
At Blackpots the lias fossils occur in clay, containing few other boulders. At Boyndie, further west, flint boulders are pitched up on the shore. And at Delgaty, ten miles inland, they occur in great abundance, along with boulders of quartz rock, but no fossils except their own. It would therefore appear
that we owe the flint boulders and lias boulders to different periods.—And as the chalk overlies the lias, it may be that its denudation was completed, and its fossils thrown up on the high grounds of the interior, previous to the formation of the boulder clay, containing the fossils of the lias. Although not in this locality, as far as we know the boulder clay has in other places (as on the banks of the Thorsa in Caithness) been found to contain “fragments of chalk flints, and also a characteristic conglomerate of the oolite, as well as comminuted fragments of existing shells.” These facts seem also to favour the hypothesis just stated.
Since I first wrote on this subject, more attention has been paid to the pleistocene deposits in the locality with which we have been dealing. I am not aware that any new facts have been elicited, regarding the topics I have made our subject to-night. And I feel that the subject altogether is one involved in considerable darkness, and that it is vain to attempt any generalisation upon it, till the local geology has been far more accurately examined and determined. To this end, the yearly labours of Mr. J. F. Jameson, of Ellon, are devoted, and each season adds to our knowledge of the country. What a curious jumble we have in that out-of-theway corner of the world. Rock-bound coasts of frowning granite, slates, and porphyries; slips of old red sandstone, patches of greensand and red crag; wealden and lias, and chalk fossils! And all, as we say in Scotland, pretty much “carded thro' other," that is, mixed up promiscuously. Ere this gordian knot be untied, much of interest to the geologist, both scientific and economic, cannot fail to come to light, -and the labour which must be extended on the examination, will assuredly not be thrown away.
The Society then resolved itself into an extraordinary meeting, to consider a recommendation from the Council, “That a sum of £10 be granted from the funds of the Society to the Gallery of Inventions and Science, in aid of the objects of that institution." After considerable discussion the proposition was negatived, the opinion of the meeting being, that, having launched the institution and set it in a fair way of prospering, it would be better to now leave it in the care of its natural guardians - viz., the Library and Museum Committee of the Town Council.
ROYAL INSTITUTION, Monday, February 20th, 1865.
J. A. PICTON, Esq., F.R.S., PRESIDENT, in the Chair.
The following gentlemen were balloted for, and elected ordinary members:-Rev. Alexander Gordon, M. A., Mr. D. M. Lalcaca, Mr. Albert H. Samuel, and Mr. Charles Robert English.
Mr. T. J. Moore exhibited some interesting marine specimens, lately presented to the Derby Museum by Mr. C. J. English, including fine examples of Velella and Porpite, and several species of fish, including a very large and finely-preserved Diodon. They were collected on a voyage to the China Seas, by Captain Cameron, of the Ship Staffordshire, and were accompanied by notes of latitude and longitude, &c.
Mr. Moore also exhibited a small but rare crustacean, presented to the museum by Mr. J. O. W. Fabert. It belongs to the family Leucosiada, and agrees precisely with the species described by Dr. Leach, in his Zoological Miscellany, in 1817, under the name of Ixa inermis, but which Professor Bell, in his monograph of the family published in the Linnean Transactions for 1855, considers to be (as with several other forms described as distinct species) a variety only of the Ixa cylindra of Fabricius. In the dozen specimens which had come under Professor Bell's observation, he found varieties agreeing well with the supposed species, and connecting the extreme forms, which without them would appear to be totally distinct. The peculiarity of the genus is the great lateral diameter of the carapace, and its prolongation into an obtuse spine-like process on either side. The longitudinal diameter of the specimen exhibited is threequarters of an inch, the lateral diameter being nearly two inches, each spine measuring half an inch, and the body part little more than three-quarters. Like the specimen figured by Leach, the limbs are wanting. The supposed habitat of the species is the Indian Ocean.