reliquiæ are plentiful; calamine has been worked in the hill W. of Whitewell, not in a vein, but in the joints and cavities of the rock: lead ore has been wrought at Dunsop.

Parallel to the axis of these large oval tracts is another singular anticlinal ridge of limestone, at a place called Sykes, on the road leading from Whitewell to the trough of Bolland: the distance between these axes of elevation being about three miles. An observer proceeding on the road towards the trough of Bolland, finds the strata of gritstone and shale dipping N. W. (the road rising in that direction), till within a small distance of Sykes, the dip is then suddenly reversed; beds of shale pass out from under the grits; limestone rocks rise beyond at a high angle to a considerable altitude, and again descending as rapidly to the N. W., are covered by the same shales, over which, in the hills around, are the ordinary grit rocks. What makes this interesting case more curious, is the occurrence of a sparry lead vein, precisely in the summit of the anticlinal ridge of limestone. The range of this vein seems to be nearly N. N. E. (See Diagram, No. 4.) The limestone is cherty, and has interposed short beds of calcareous spar and pearl spar. At Ash Knot, two miles from the Slaidburn limestone, on the S. E., is another detached mass of lower limestone, also exhibited by 'dislocation, and marked by the occurrence of lead veins,

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Approaching the valley of the Ribble, we find at Widgill, near Bashall, another detached mass of lower limestone, with abundance of fossils.

Ribblesdale.In Lower Ribblesdale, the principal mass of this lower limestone lies about Clitheroe, where it shews itself in the castle hill and other points, ranging N. E. toward Downham and Rimmington, and dipping S. E. toward the ridge of Pendle hill. The Ribble flows in limestone from near Gundleton to above Eadsford bridge.

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Most of the laminated dark limestones of Craven; appear as much connected with the shale above, as with this lower member of the mountain limestone series. They may, in fact, be considered

as the feeble representatives of the upper limestone group of Yoredale. An excellent section of these beds is afforded in the quarry on the bank of the Leeds and Liverpool canal, near Thornton, where alternations of calcareous and argillaceous beds rest upon a thick mass of laminated and crinoidal limestone. (See Diag. No. 5.) The range of the beds here, as in most parts of the neighbouring country, is N. E. Similar beds, with the same strike, occur at Lawley, Rimmington, Twiston, Gisburn, Bradwell, Broughton, &c.

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Lothersdale.-A very remarkable exhibition of these dark limestones appears in the narrow valley of Lothersdale, which is formed along an anticlinal axis, ranging nearly N. E., between hills of shale and grit. The limestone is dug in very large quarries, nearly in the middle of its range, where the general N. W. and S. E. dips are locally altered to N. E., and W. by N. (30°). The stone is hard, fine grained, thinly laminated, of a blue colour, and contains many lamina of chert, and cross strings of calcareous spar. This latter circumstance is always observed near the contortions and other dislocations which are so frequent in the laminated shales and dark limestones of Craven. In the eastern quarry on the south side of the valley, occur veins of sulphate of barytes, ranging E. by S. across the anticlinal axis, and dipping to the south. The limestone cheeks of the vein are altered in character. Sulphate of barytes likewise occurs in many of the joints which range N. W, and S. E. The dip of the beds is N. E. 30°. Few traces of organic remains can be perceived. Shales and alternations of argillaceous limestone cover the rock. (See Diagram No. 6.)

Skipton.—A similar and more extensive exposure of the same dark laminated limestone occurs in the valley of elevation which ranges from Skipton E. by N. to Bolton Abbey. The sides of this valley are formed of the Craven shales, surmounted by millstone grit, dipping each way from the limestone ridge to the S. by E. and N. by W. The axis of elevation is crossed by certain transverse undulations of the strata ranging N. and S., accompanied by parallel slips, and sparry

and partially metalliferous veins. In the great quarry near Skipton, which is opened on the north side of the axis, with a dip N. by W. of 40° to 70°, a sparry vein, with many ramifying strings, ranges N. and S., and dips 45° ? to the E. That at Bolton (See Diagram, No. 7.) shews a very remarkable dislocation, ranging N. and S., accompanied by spar and lead ore. All the quarries display a very great mass of shales and limestones both compact and crinoidal, black and grey,-spar strings abound in the beds, generally running transverse to the surface of stratification, whether this be arched or inclined N. or S. In a small quarry E. of and very near the town of Skipton, a minor anticlinal ridge, running E. by N., or parallel to the main elevation, is cut across so as to allow of a careful study of this curious phenomenon. There is here seen one rectangular upward fold, ('saddle') between two relative depressions, ('troughs'), the flexure of both the upward and downward folds being by much most acute in the lower parts of the quarry, (See Diagram No. 8.), and becoming rounded and evanescent above, as if the bending force had been laterally applied, and the resistance to it comparatively slight in the upper parts. The anticlinal angle is 90°, the steepest and shortest slope of the beds is to the south, (50°), on which side also is the most violent return to a nearly horizontal condition. The lower beds of the section are limestone, thick, partly of a black colour, and partly crinoidal; the upper beds are shale, with some argillaceous limestone. Inhumerable spar strings divide the beds, with an evident general tendency to be at right angles to their surfaces. Slickenside' faces appear on the beds of stone and in the spar veins, and the prevalent direction of these on the horizontal beds is N. and S., as if the beds had been made to slide laterally.

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The great anticlinal elevation of Skipton appears to be a continuation of that at Thornton, whose range passes between Pendle hill and Clitheroe, and parallel to the lower Ribble. In the other direction it passes eastward along a characteristic and dislocated country, by Blubberhouses to Harrowgate, being in fact one of the most remarkable subterranean ridges on record. The Lothersdale ridge is prolonged

nearly in a parallel course on the line of the Rearing Beds' of Barrowford, and Padiham heights, and Whalley; the millstone grit ranging from thence by Ormskirk to the sea, and dipping to the S. E., indicates the continuation of the same combined axes of elevation, while the coalfield of Burnley lies in a parallel depression on one side, and Longridge fell forms its boundary on the other.

Rylstone.-North of the Skipton anticlinal, and nearly parallel to it, is another very interesting line of elevated limestone masses, ranging from the limestone valley of the Aire, by Flasby, Craco, and Burnsall, to Greenhow hill. From Flasby towards the Wharfe, the limestone passes along a valley, continually expanding in area as it proceeds to the N. E., so as to unite with the calcareous masses of Wharfedale, and dipping in the most distinct manner beneath the shaly slopes and gritstone summits of the Rylstone and Flasby fells; on the northwestern side it is covered by shaly hills connected with Ryeloaf. Its upper beds, as seen about Craco, are of the dark laminated stone, so frequent in the Craven country, and below are solid gray and blue crinoidal rocks. In passing along its southern border, toward Burnsall, the average range points E. by N., and the steep southern dip soon brings it, near the village of Burnsall, down to the Wharfe, which, here changing its course, continues on its edge as far as Appletreewick. From Burnsall it extends E. by N., growing narrower continually to the anticlinal ridge of Nursa Knot. Between Nursa Knot and Greenhow hill is a depression of the limestone ridge, filled with shales and grits, called 'dead ground.' Its range is nearly N. N. E., and it is crossed by many veins. (See the Map.)

Greenhow. The Greenhow hill ridge rises into two eminences, called Greenhow hill and Coldstones; from both of them the beds dip rapidly to the north and south, (the dip diminishing as the distance from the axis augments,) 40°, 30°, 20°, 10°. Many metalliferous

See Whittaker's Craven, for an account of this local name.

veins cross the ridge, ranging E. or E. S. E., and are traversed by north and south lines of irregular cavities called 'gulphs,' which are full of broken portions of the bordering rock, and are said to 'ruin the veins.' Shales and grits of great thickness, inclosing a thin limestone, envelope on all sides the oval mass of Greenhow limestone, which is more than 100 fathoms thick, the bottom having never been reached.

Wharfedale. From Appletreewick by Burnsall, Grassington, Coniston, as far as Kettlewell, the limestone so largely developed in Wharfedale conforms to the southern type. From Kettlewell downward to Litton dale, its area is narrow, and so continues on the left bank to Grassington, but on the right it expands considerably in Litton dale, and on the hills above Kilnsea, to connect with the great limestone plateau of Malham moors.

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The thickness of limestone exposed between Kettlewell and Great Whernside is about 900 feet. According to my own observations, corrected in part by an account given me by the men employed in a mine on the bank of one of the streams which I explored here, the series downward consists of the following terms, (under grits and shales.)