On the Cycadeoideae, a family of fossil plants found on the oolite quarries of the Isle of Portland / [William Buckland].

  • Buckland, William, 1784-1856
Date:
[1828]
Catalogue details

Licence: Public Domain Mark

Credit: On the Cycadeoideae, a family of fossil plants found on the oolite quarries of the Isle of Portland / [William Buckland]. Source: Wellcome Collection.

    7/44
    Oolite Quarries of the Isle of Portland. By THE Rev. WILLIAM BUCKLAND, D.D. F.G.S. F.R.S. F.L.S. PROFESSOR OF MINERALOGY AND GEOLOGY IN THE UNIVERSITY OF OXFORD. [Read June 6th, 1828.] About twenty years ago I saw for the first time specimens of these fossil plants, in the collection of H. H. Henley, Esq. of Sandringham near Lynn. They had been procured by him from the celebrated freestone quarries of the Isle of Portland, where they were known to the workmen by the name of petrified birds-nests, their external form bearing a rude resemblance to the shape and size of a common crow’s nest. My attention has been recalled to this subject by a communication which I received in 1825 from Sir George Grey of Portsmouth, who transmitted to me a similar fossil found also in the Isle of Portland, and permitted me to make the drawings of it represented in Plate XLVII. On my showing this specimen to Mr. Webster, he informed me that he had presented two similar fossils from Portland to the Geological Society of London*. There are also three more specimens in the museum of Mr.Sowerby, two of which he has kindly permitted me to engrave in Plates XLVIIL and XLIX. These specimens are all exclusively from the Isle of Portland. The mineral condition of these plants is almost entirely siliceous, varying from coarse granular chert to imperfect chalcedony; it resembles that of the petrified trees which abound in Portland and often measure many feet both in length and circumference, in some of which Mr. Brown has recognised * Mr. Webster informs me that he found these plants accompanied by large silicified trunks of dicotyledonous trees, in a stratum which he designates by the workman’s name of Dirt.bed, being about one foot thick, consisting of a dark brown substance, and containing much earthy lignite ; it lies immediately above the Portland building~stone, and divides it from slaty calcareous beds, which Mr. Webster doubts whether to refer to the Portland or to the Purbeck series. See Mr. Webster’s paper on the Purbeck and Portland Beds, Geol. Trans. 2d series, vol. ii. Part I. 3 F 2