the relation in this respect of other parts of England, Scotland, and Ireland. North of England, and Scotland. COAL FORMA TION Transition series CARBONIFEROUS LIMESTONE SERIES Transition series ་ རྩྭ OLD RED FORMATION Derbyshire, North and Belgium, and South Ireland. Coal, shale, grits, and Coal, shale, grits, and Coal, shales, Coal, shales, grits, and iron- grits, & ironstone ironstone ironstone. stone. ར་ Kulkeagh grit D Kulkeagh shale Limestones and Alternations of red Alternations of red sand- Alternations of red sandstone and Red sandstones and Red sandstones and Red conglomerate Kulkeagh lime stone Loch Earn shales and grits Enniskillen lime stone Alternating red grits and lime stones Red sandstone and conglomerate It is necessary, for the sake of a careful comparison between one country and another, to divide the larger groups of associated strata into convenient assemblages or series; but in doing this we must be ever mindful that our lines of division contain much that is arbitrary, and more that is merely of local application. The carboniferous system undoubtedly does permit itself, in almost all situations, to be considered in three series, characterized by the prevalence of coal, limestone, and red sandstone; and corresponding to some general physical conditions which anciently prevailed in the regions where this classification applies. But to draw hard lines of division between these groups is only possible in local cases, where geological accidents have broken the continuity of natural operations; for where on such accidents (whether arising from near or distant convulsions) have occurred, the three groups pass into one another, by gradual approximation of character, or repeated alternation of deposits. In Somersetshire the distinction of coal series and mountain limestone series is absolute; but in Yorkshire and the North of England, the two groups are com pletely united by intermediate and almost indefinite alternation of cal, and ironstone. Though in some sandstone, limestone, shale, coal, and ironsto 2 countries the old red conglomerate shews no sign of union to the mountain limestone, yet near Bristol, round all the region of the Cumbrian slate, along the Penine chain, and in Tweeddale, the alternation of red sandstone and mountain limestone is a common and characteristic phenomenon. Such a series of strata is in fact double, and belongs equally to the superior and inferior groups and instead of being considered neutral, bor named as a distinct a series, should rather be included in both, as indicated by the mode of arranging the brackets in the table just given¡ to 99mbi79 alt go yoll gigold e botimbs on abod yub bas manos 9't talt Groups or series, quite distinct in their middle terms as limestone and shaley may yet graduates into one another, so as to leave no line of demarcation, but as band of transition deposits. This phenomenon depends on the same general principle as the union of deposits by alternatiónéviz. › a change of the physical conditions of the region ; the difference between the two orders of effects produced in bue period, may hereafter reveal to us the geographical circumstances of the deposits, especially their distance from the centre of the physical disturbance.I sdt to aasd it al 1916” notzino') to 2d991 978le 106 guiqqib ozls woggs abod yno bae obrvomoign09, 9lsbajo.I ydrid Transition groups formed by gradation or alternation of the terms of any series may be thus represented. Let cd stand for, coal, limestone, and red sandstone.ort on bod godu& ri biswdron lttu Cow 110319126Ɔ mi m552 978 yoT i of moinsdyr soft, godz. 01 25 06 Gradation of substance.dsdoro, tour glo dat Alternatio of beds. 1 = C+C+C Coal formation 2 Coal formation Transition group){ 953 +1 cthrel men Transition group b + {h #b+1+1 .: il 1 to 29226nt bob un adı mot bi bim, da zbu Mountain, limestone for _L+LTL mation 4 4 Mountain limestore for--}·L+L+L' mation Red sandstone formation R+R+Rod Red sandstone formation = vir o9uLIA OLD RED FORMATION. Throughout a great part of the North of England, the lower scar limestone rests on the slate rocks, without any interposition of the old red formation (Kendal, Ingleborough); in, other districts, (Brough, Lowther, Ravenstonedale,) red, purple, and white micaceous grits and shales alternate abundantly with the lower limestone beds; and in some localities coloured clays, and conglomerate sandstones, occupy irregular spaces between the limestone and the slate.go 211 E to sbont oft rd botesibm as dod i bobiom d It is chiefly on the evidence of intermediate geographical position, that these conglomerate and clay beds are admitted as belonging to the old red formation; for I am not certain that in any one locality they are really seen to lie beneath the mountain limestone. They are confined to valleys in' the slate formation, where these approach the limestone; they never follow that rock to its escarpments on high ground; and no where rise, to a great height above the sea, except in Mell fell, and other lower hills at the foot of Ulswater. The following localities may be indicated. North of Ulverston, red and bluish beds of gritstone and clays, dipping southward toward the limestone from the slate rocks of Coniston water. In the banks of the Lune, north of Kirby Lonsdale, conglomerate and clay beds appear, also dipping southward from the silurian beds and toward the limestone which declines in the same direction (toward the south). The same beds appear a little northward in Barbon Beck, near the vertical limestone, but not so as to shew their relations to it. They are seen in Casterton woods in such a way as to make it the most probable supposition that they dip under the limestone there. Similar beds are seen in the Rother, near Sedbergh, and in the Mint, near Kendal. In the lower part of Ulswater they abound, and form the rounded masses of Mell fell, and Dunmallet. At Dacre castle they decline from the slate country toward the limestone, so as to make it probable that they pass under it. The Lowther river, and some of its branch streams near Bampton, disclose similar beds between the limestone and the slate. Beds of conglomerate, much related to these, occur in the Hilton valley, near Appleby, between the limestone and the slate. It is almost exclusively a valley deposit, though deeply cut through by the lower part of the valleys in which it occurs. It seems to have been formed during some period of disturbance affecting the region of the Cumbrian mountains, just as similar rocks along the Grampians and Lammermuirs are referred to similar, perhaps contemporaneous disturbances. The characters of the conglomerate are plain and striking. Large and small pebbles of a brown colour, sometimes blue internally, in immense abundance are accumulated together, and partially cemented into vast irregular beds by red clay, red sand, or calcareous spar. The pebbles vary in size, number, and degree of cohesion to the matrix in different beds. With these alternate other beds of red and white clay and red sandstone, almost or wholly devoid of pebbles. They are but feebly cemented in the clay and sand, and may be detached by a blow of the hammer, leaving a concave, smooth impression. In some cases I have imagined thats one pebble indented another. But when calcareous spar is the cement, as is common about Kirby Lonsdale, the compound is more firm and makes a pretty appearance. The pebbles which occur in this rock at Kirby Lonsdale, are be Rarely-Red limestone with lithodendra, a few crinoidal joints, and other organic bodies tule bus s P Blue limestone, with crinoidal joints, and a fragment of syringopora. Hornstone compact, purplish. Calcareous spar. Conglomerate of fine grain, micaceous, with white effervescing particles. Quartz pebbles, holding micaceous iron ore. Abundantly-Grauwacke, same as in the neighbouring fells of Casterton, Hougill, &c. By this list will appear the limited extent of the current which brought together these pebbles, no trace of granite, syenite, porphyry, greenstone, amygdaloidal slate, or any of the Cumbrian rocks which are remote from the valley;-the same data may perhaps confirm our belief that the rock is of higher antiquity than the limestone series, for if it had been of the age of the new red formation, how could it happen that none of the limestones, gritstones, and shales of the then uplifted Penine chain, of the sources of Lune, or the neighbouring country should have found their way to this deposit? The few limestone pebbles really found in it may have been derived from the Coniston limestone in the Shap country, but this is uncertain. Veins of calcareous spar traverse these beds, and sometimes divide the pebbles, as at Oban in Argyleshire, and in the Nägelflue of the Rigi. This proof of the posteriority of such veins to the rocks which enclose them, joined to the evidence afforded by the quartz pebble with micaceous iron ore, is of great value in limiting the question concerning the age of mineral veins Though, as before observed, the limestone is not any where in its higher ranges based on conglomerates, numerous and large fragments of grauwacke are often seen embedded in its lower strata, as in Kingdale, Ingleton dale, &c., and quartz pebbles, as at Underbarrow scar, Winder, &c. In a little stream descending from Moughton scar, nearly west of Horton, to the Ribble, the slate is covered by a series of beds which I did not find elsewhere. Immediately on the slate rests a layer of fragmented quartz and slate in a calcareous paste. four feet of shale, containing an indurated bed; next, a bed, eighteen inches thick, of fragmented quartz and slate with pyrites; then two feet of lumpy shale; three feet of lumpy limestone; five feet of broad, laminated shale, which throws out the water. Limestone scars come on above. Conglomerate beds underlay the limestone of the Penine chain in Hartside, and Hilton Beck. ALTERNATING RED SANDSTONE AND LIMESTONE. Above are This intermediate or transition group, until lately little noticed by geologists, is of great importance in all questions concerning the comparative age of unconnected deposits of the older mountain limestone series. My attention was first drawn to it in the neighbourhood of T |