The Comparative Geology of Hotham, Near South Cave, Yorkshire
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**s?wifr 472 THB GEOLOGIST. smaller or ventral valve, showing that the muscular impressions were exactly similar to those observable in Spirifera; no septa existed in this valve, so that th^ shell cannot be classed with Pentamerus. None of the fragments, however, exhibited a trace of spiral processes, but this is no proof that they might not have existed. The terms Athyris and Atrypa have been made use of in this paper, but I wish it to be distinctly understood that I do not recommend their adoption. I used them as mere names, and on account of their priority of date; but, as the generality of naturalists on the Continent, and some in Great Britain, have for some time past made up their minds to repudiate both M'Coy's and Caiman's misnomers, for the reason that they invplve a zoological mistake, my readers can adopt M. d'Orbigny's substitutes of Spirigera for Athyris, and Spirigerina for Atrypa, although other denominations might have been preferable. ERRATUM. In page 412, line 19, instead of genus Atrypa, Dalm. = Spiri/erina, D'Orb., read Spirigerina, d'Orb. THE COMPARATIVE GEOLOGY OF HOTHAM, NEAR SOUTH CAVE, YORKSHIRE. By the Rev. T. "W. NOBWOOD, of Cheltenham. (Continued from page 424.) II. It is about a mile across the Lower Lias, on which the villages of North Cave and Hotham are situated, to another gently-rising ground which ascends out of Hotham Park to the eastward in a beautiful sloping bank, and being tastefully planted with stately trees, contributes very much to the charm of the scenery. Coming in with my hammer to the ancient village, in the bright and odorous evenings of midsummer, I have often been arrested by the sweetness of this place; and, enamoured of its serene and peaceful beauty, I have loitered to admire its dark plantations, and the greensward slope that I am now describing, and the illuminated wold rising high in the distance. It is the low escarp ment of the Middle Lias which declines thus pleasantly into the park at Hotham. As we go out of North Cave towards Beverley, this bank may be observed to rest upon soft blue shales, which have hitherto supplied no fossils. When we begin to ascend it, we may turn into a copse on the right-hand side and study the section in a marl-pit, or we may notice the roadside cutting. In either case, we shall observe that the beds change as follows:—From blue shales at the bottom and lower part of the ascent, through brown earthy-looking shales and sand with irregular broken bands of nodular clay-ironstone, one of which enclosed Fucu.xa. l*ho« IJSCVIASOTI daL&.Ti£h. NOEWOOD—GEOLOGY OF HOTHAM. 473 a cast of Unicardium cardioides, to a hard rock-bed of the true Marhtone, two or three feet in thickness, which again is capped at the top of the ascent by a very rusty, rubbishy, and ferruginous rock. It is in the last division only that I have succeeded in obtaining fossils at this place in any quantity worth mentioning; and they are always in a very corroded and imperfect condition. The most plentiful forms are Belem- nites, and next to them, masses of Rhjnchonella tetraedra; but with perseverance and good fortune Terebratula resupinata and other charac teristic shells of the Middle Lias may be collected here. This zone may be traced both towards the north and south, though it does not maintain that upland character which it assumes in Hotham Park, for more perhaps than two miles of its course. It is seen in one direction, near Hotham, as we leave that village by the road to Beverley; in the other it crosses the turnpike at Everthorpe, and passes close by the castle and church of South Cave. There is a moory valley with a surface of sand and peat lying along on the north side of Hotham towards Newbald, between the escarpment of the Lower Lias on the one hand and the rise of the chalk-wold on the other; a favourite haunt, in spring and summer, of lapwings and sand-martens. Two pits, which were opened in this valley for marling, about a mile from Hotham church, have exposed a substratum of remarkable drift which is very well deserving of examination. It consists of a medley, in great masses more or less rounded, of all the surrounding formations, from the " Posidonomya- bed " to the White Chalk, and contains some organic remains distinctive of rocks which are not known at present to exist in situ anywhere in the neighbourhood of Hotham. For example, it has supplied an Ammonites cordatus, with a matrix of Oxford clay, which leads me to suspect that that rock might be found stratified no great way off, especially as the Kelloway rock occurs in its place hardly more than a mile to the eastward. The fact, too, that the formations composing this drift lie mostly to the westward of their proper lines would indicate that the great transporting waters which accumulated these ponderous and disordered masses had their origin in some eastward direction. Mixed indiscriminately in the general ruin lie large and small blocks of Middle Lias Mwlstone, dissimilar, however, in colour and texture to the marlstone which I have mentioned as cropping out near North Cave, and which may also be traced through Everthorpe and South Cave in its progress towards the Humber. The colour of these rocks 474 THE GEOLOGIST. is more darkly ferruginous and their texture markedly oolitic or granular, though not unfrequently they change to a deep green hue, imparted to them by the protoxide of iron, when the granular structure becomes less observable. The fossils, also, which they enclose, though exceedingly distinctive and familiar, have not yet been found in situ at Hotham. They are the common forms of the true Marlstone—the " Bpinatus " and " Margaritatus " zone of Oppel and Wright—which is shown in typical seotions, as at Gretton, near "Winchcombe, in Glouces tershire, to occupy the top of the Middle Lias in the southern counties. I collected here the large Peoten equivalvis and P. oorneus, both of which were plentiful as usual, Belemnites, Plewomya unioides (?), Cardinia crassissima, and Ammonites Englehardti, with some others. The drift which I have been now considering contrasts remarkably, from its mixed character, with those other and almost homogeneous deposits which have been shown to cover the neighbourhood of North Cave. III. It may be about 200 yards across the Middle Lias; but its junction with the rock next succeeding is not well exhibited. The eountry is now flat to the foot of the chalk, and the sequence of the different rocks that traverse this level is partly undeterminable from lack of sections, and partly obscured by drift, so that I could not make it out with sufficient exactness. I ascertained, however, that the ferruginous beds give place to an inconsiderable band of yellow tenacious clay; and that this again is apparently succeeded by a still narrower zone of very peculiar marly limestone, which I shall call provisionally the LISNIFEBOTTS MAEL, and describe as fully as my present materials will permit. I regret that these are not more ample, which is owing, in part, to my limited opportunities. I believe this to be an exceptional bed, possibly it may even be unknown hitherto, and unrecorded in our series. Its lithological character might refer it to the Upper Lias; but its fossils in general, and particularly in one or two instances, are muoh more of Oolitio than Liassic types; and consequently I should be inclined, in the existing state of my knowledge, to assign it an inter mediate place between the Upper Lias and Inferior Oolite, somewhere in that " debatable ground" which has lately received such elaborate illustration from Dr. "Wright. I have reason to suspect the existence of the Upper Lias Clay at Hotham; and I shall hope to prove that I have seen there the lower portion of the Inferior Oolite, a little NORWOOD—GEOLOGY OF HOTHAM. 475 above this Marl; but, until the relative places of these rocks are accurately known, I desire to speak with great reserve of the horizon and affinities of the "Ligniferous Marl;" and shall better employ myself in discussing its appearance, so far as I have really seen and studied it, in the hope that I may induce some geologist with more leisure and experience to go down to Hotham and complete the investigation. A small opening made this year for road-stone, in the lane-side between Hotham and the Drewton turnpike, exhibits the place, breadth, and character of this limestone. Its position might argue it at first sight to be " Upper Lias;" its width is but a few yards; and structurally it is a band of sharp irregular uncompacted Stones, which may be divided, not naturally but for convenience of description, into two kinds. Those of what I shall call the first sort are com paratively soft and marly, of a yellowish-grey colour and general fresh-water aspect, interspersed throughout with fragmentary re mains of land-plants, particularly of a fern, with a frond-lobe much resembling in outline that of the common Polypody (Polypodium mlgare). The venation is generally distinctly preserved : the lobe has a prominent mid-vein, from which alternately, on either side, branch out the lateral veins, these last being twice-forked and thus divided into four branches. I am indebted to Professor Phillips for pointing out, when I lately read a paper on this subject before the British Association at Leeds, the affinities of this] fern in general; and the interesting fact which I had omitted to notice, that one specimen in my collection shows its fructification.