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Show 126 PROOFS OF FORMER d. ver a vast area, f rom about 475 °o to 60°h, temperature, exte~ mlgdo Melville Island, to near 5 nort or per I1 aps, 1·r we me u e • • • latitude*. . · (J'ination the dtstnbut10n t to restore 10 Imnb h d' When we attemp . d t tlJat remote epoc ' we Is-f land and sea, as tl ley .e xis.t e ta sent limited to 1a tt· tu de s o . £ nnatiOn IS a pre h 1' cover that our m o d c can only hope, t erewre, 6 · f cancer, an w 1 north of the tr pic 0 d' . f the earth so far as re ates to to point out t l1 at th e co.n Itton o as such a' s the theory b eIw! re d rctiC zones, w . . 1 our temperate an a t' 'pate Now there IS scarce y ,d h led us to an tel ' . A . offered woul ave . d 'n Europe, Northern Sia, or any land hitherto :xamme 1 b n raised from the bosom of . ltch has not ee k h' h North Amenca, w 1 . . f h arboniferous roc s, or w IC ' the deep, sm· ce tl1 e onlol' lll 0 t eb c quently acquire d a dd'1 t·1 0na l if previously raised, has nobt su se again all the marine strata, altitude. I f we were. to su met rget he most recent she 11 Y be d s , from the transt· t' n hmestone o ld · 10 • untains alone wou remam . f some primary mo 'd d . 1 the summits o Th .c ts l't is true, consl ere smg y, h t • ese 1ac , . · above t e wa ers. 1 . sality of the ancient ocean m 1 . astotleumver h are not cone usive b the movements of eart - h isphere ecause . . f I the northern. emth e su bs1· 'a ence as well as the upraismg o. t 1e quakes occasiOn : . and sinking of partlcu 1a r d b the alternate nsmg . 1 surface, an Y sive pen.o d s, a great area may become entire y spaces, at succes . d 't althou()'h the whole has never covered with manne epost s, t'meo nay even though the h 1 waters at one I , ' been ben eat t le 1 d d sea may have continued un-relative proportion of a~ I an . d There is however, the altered throughout the w. o te per~o a~ hypothesis, because the Ption acrams sue d highest presum o . h is now in great excess, an land in the northern hemishp eldre . ducc us to suppose that, t alone s ou 10 this circums ance h' h the surface has undergone, amidst the repeated changes ':' ICd . much greater degree. h lly predommate m a t the sea as usua . 1 nposition and fossil conten s But when we study the mmera cor . been found in Italy, Spain, Sicily, or an.y of • Our ancient coal-formation has not Wh th ny of the ammonitiferous lime-the more southern countries o~ Europ~. Sicil e (T:o:mina for exam pi~) c~n be con; stones of the Southern Apenrunes ~n. . t~ our carboniferous senes, ts not ~e sidered as of contemporaneous ongm Wl eneral character of the organic rema.tDJ determined; but it is conjectured, from ~~e g to some part of oux secondary senes, of the A pennine limestones, tha~ they e ong from the lias to the chalk incluSlVe. CHANGES IN PHYSICAL GEOGRAPHY. 127 of the older strata, we find evidence of a more positive and unequivocal kind in confirmation of the same opinion. Calcat·eous rocks, containing the same class of organic remains as our transition and mountain limestones, extend over a great part of tbe central and northern parts of Europe, are found in the Jake district of North America, and even appear to occm· in great abundance as far as the border of the Arctic sea*. The organic remains of these rocks consist principally of marine shells, corals, and the teeth aud bones of 6sh ; and their nature, as well as the continuity of the calcareous beds of homogeneous mineral composition, concur to prove that the whole series was formed in a deep and expansive ocean, in the midst of which, however, there were many isles. These isles were composed partly of I?rimary and partly of volcanic rocks, which being exposed to the erosive action of torrents, to the undermining power of the waves beating against the cliffs, and to atmospheric decomposition, supplied materials for pebbles, sand, and shale, which, togethet• with substances intl'Oducecl by mineral springs and volcanos in frequent eruption, contributed the inorganic parts of the carboniferous strata. The disposition of the beds in that portion of this group which is of mechanical origin, and which incloses the coal, has been truly described to be such as would result from the waste of small islands p1aced in rows and forming the highest points of ridges of submarine mountains. The disintegration of such clusters of isles would produce around and between them detached deposits of various dimensions, which, when subsequently raised above the waters, would resemble the strata formed in a chain of lakes. The insular masses of primary rock would preserve their original relative superiority of height, . "' It appears from the observations of Dr. Richardson, made during the expedi bon under the command of Captain Franklin to the north-west coast of America, and from the specimens presented by him to the Geological Society of London, that, between the parallels of 60° and 70° north latitude, there is a great calcareous ~onnation, stretching towards the mouth of the Mackenzie rive!', in which are Included corallines, productoo, terebratulites, &c., having a close affinity in generic c~aractcrs to those of our mountain limestone, of which the group has been con~ Idere.d the equivalent. There is also in tho same region a newer series of strata, In which are shales with impressions of ferns, lepidodendrons, and other vegetab~~ s, an~ also ammonites. These, it is supposed, may belong to the age of our oolitic senes.-Proceedinos of Geolooical Society, March 1828. |