LIST OF THE OFFICERS OF THE GEOLOGICAL SOCIETY OF LONDON. The Duke of Argyll, K.T., D.C.L., F.R.S. | J. Gwyn Jeffreys, Esq., F.R.S. H. Bauerman, Esq. Prof. G. Busk, F.R.S. J. F. Campbell, Esq. Frederic Drew, Esq. Sir Charles Lyell, Bart., D.C.L., F.R.S. J. Carrick Moore, Esq., M.A., F.R.S. Sir P. de M. Grey Egerton, Bart., M.P., Prof. A. C. Ramsay, LL.D., F.R.S. F.R.S. Robert Etheridge, Esq., F.R.S. John Evans, Esq., F.R.S. David Forbes, Esq., F.R.S. Captain Douglas Galton, C.B., F.R.S. Samuel Sharp, Esq., F.S.A. Warington W. Smyth, Esq., M.A., F.R.S. W. Whitaker, Esq., B.A. Rev. T. Wiltshire, M.A., F.L.S. Assistant-Secretary, Librarian, and Curator. Clerk. Mr. W. W. Leighton. Library Assistant. Museum Assistant. Mr. B. B. Woodward. EVENING MEETINGS OF THE GEOLOGICAL SOCIETY. TO BE HELD AT BURLINGTON HOUSE. [Business will commence at Eight o' Clock precisely each Evening.] The Library and Museums at the Apartments of the Society are open every day from Ten o'clock until Five. Publications to be had of the Geological Society, Burlington House. QUARTERLY JOURNAL. (Vols. III. to XXVII. inclusive.) £ 8. d. 040 063 056 03 0 0 10 0 Price to Fellows. 13s. 6d. each (Vols. XV. and XXIII. 16s. 6d.), in cloth. CLASSIFIED INDEX TO THE TRANSACTIONS, JOURNAL, &c., by G. W. ORMEROD, Esq. New Edition, to the end of 1868. Price 4s. To Fellows, 2s. 6d. [Postage, 5d.] GEOLOGICAL MAP OF ENGLAND AND WALES, in 6 Sheets, by G. B. GREENOUGH, Esq. New and Revised Edition. Price to Fellows, in sheets, £2 2s. Single sheets may be purchased at the following prices:-No. 1, 4s. 6d.; No. 2, 3s. 6d.; No. 3, 10s. 6d.; No. 4, 88. Od.; No. 5, 12s. Od.; No. 6, 7s. 6d. 9. The GEOLOGY of NORTH-WEST LINCOLNSHIRE. By the Rev. J. E. CROSS, M.A., F.G.S. (Read November 18, 1874.) [PLATE V.] THE Locality to which I would draw attention this evening is the extreme north-west corner of the county of Lincoln-the district, in short, as the rough map (fig. 1) will show, bounded by three rivers, the well-known Humber and Trent and, eastwards, the little Ancholme-this last a strange name to modern ears, but one which has been honoured by the mention of that old English classic, Isaac Walton. It is a corner of the land unknown to fame; but we are now becoming celebrated commercially by the recent discovery of a most extensive and valuable deposit of iron-ore, Fig. 1.—Sketch Map of N.W. Lincolnshire. respecting which I shall have something to say by and by. But, besides this commercial importance thrust upon us, the district has a special value in the eyes of the geologist as being a middle link in the chain of the Jurassic strata, between their development in the south and their somewhat dissimilar appearance on the Yorkshire coast. The labours of Mr. Judd and Mr. Sharpe, in the southern portion of the county, have brought into clear light the commencement of this variation. But the state of things in this northern corner has not as yet been brought before your notice. Q. J. G. S. No. 122. K The accompanying section (fig. 2) gives a general idea of the district. Three escarpments are represented, and two long sloping Fig. 2.-Section from the Chalk Wolds of N. W. Lincolnshire to the a. Cornbrash and Great-Oolite clay. b. Lincolnshire Limestone. c. Upper Lias clay. d. Rhynchonella-bed. e. Capricornus-clay-Middle Lias. g. Lower Lias clay. h. Scunthorpe Ironstone. k. Infra-Lias. 1. Keuper. plains between them. The westernmost scarp is capped with Lower Lias (Bucklandi-zone), the middle one with Lincolnshire Limestone; and the easternmost is the Chalk Wold. Both these latter elevations are characteristic and enduring features in the county. The limestoneridge is called the Cliff," and runs pretty nearly due south from the Humber to Lincoln, and further. The wold trends S.E. towards Boston and "The Wash." The westernmost elevation of the three is not so continuous. What I desire to do now is to give a slight sketch of the Liassic and Oolitic strata here exhibited, from west to east, from the lower rocks to the higher. The bed of the river Trent is in the Keuper Marls (fig. 2, 7). When a railway-bridge was built here a few years back the sinkings for the piers were all through this formation. It would be natural to suppose, then, that the Rhætic beds would make their appearance on the eastern shore, especially as they have been found well developed elsewhere in the county; but I have as yet no sufficient proof of their existence. Nor do I find any trace of the famous bone-bed, nor, again, any single specimen of Avicula contorta, for which I have searched very diligently. Nor have I seen any one specimen of the true Ammonites planorbis. As far as my researches go, the first strata next above the Keuper are those which contain Ammonites angulatus and A. Johnstoni; and if this is so, a considerable gap in the series is exhibited. As regards these two Ammonites, both appear together in the lowest beds (figs. 2 &3,k); but A. angulatus seems to reach far above the extreme limit of the other, throughout a zone of, say, 150 feet or more. Chalk. |