GEOLOGY. 



GEOLOGY. 



0-1 



the whole there seems ration to think the new red-sandstone system 

 could not hare occupied a long time in its formation compared to 

 other deposits of equal thickness. [RED-SANDSTONE FORMATION.] 



Oolitic System. Into the same European and Asiatic basins which 

 received the red clays, red sands, and mognesian limestones of the last 

 system, subsequent agencies brought blue clay*, sands more or leas 

 ochraceous, and limestones characterised by an oolitic texture. These 

 deposit* are parallel to the old rocks below, and no trace of nny change 

 of level in the region where they occur has been noticed in England 

 perhaps not in Germany. Mutt we refer to some distant convulsion 

 fur an explanation of the change of sediments, and for the equally 

 great change, or rather sudden development, of organic life, which 

 comes in with the oolitic era ? New and more abundant forms of 

 plants (t'ytaderr), with many varieties of Zoophyla, Moliuica, Cruttacea, 

 fishes, and gigantic reptiles of the laud, rivers, and the sea, mark thu 

 oolitic rocks, and render them justly comparable, as a system, to the 

 great carboniferous assemblage of strata. Locally indeed the oolitic 

 rocks yield coal among the interpolated grits and shales, just as 

 happen* among the rocks interatrutiued with the older mountain 

 limestone. 



The resemblance of the oolitic to the carboniferous limestone tracts 

 is extremely great in general features ; and the reason is that both 

 are essentially sea-deposits, characterised by calcareous rocks formed 

 jn the deep sea, and liable to admixtures of sandstone and shales along 

 the shores. In such situations each u carboniferous. Both are highly 

 rich in oceanic life, but during the formation of the oolitic rocks there 

 is no proof that anywhere such excessive richness of vegetation was 

 renewed on the land as that which yielded the mass of coal-plants 

 in an earlier period. [OOLITIC SYSTEM.] 



Cretaceous System. The last portion of the series of secondary 

 strata was deposited in the same oceanic basins as the earliest as fur 

 as Europe is concerned, but this is not the cose in America. Generally 

 in Europe the cretaceous rocks hare their stratification parallel to 

 that of the oolites, though some uncomformity in this respect occurs 

 in Yorkshire and Dorsetshire ; and in the south-east of France dislo- 

 cations affected the oolitic strata before the production of the creta- 

 ceous rocks. But these comparatively slight movements of the bed 

 of the sea appear totally insufficient to account for the complete 

 change in the chemical and minerologicnl character of the rocks, and 

 the new orders of Xoojihyta and M oilmen which date from the 

 commencement of the cretaceous era. 



Sands coloured green by silicate of iron, white soft limestones with 

 beds or nodules of flint, seem to bespeak an origin from the waste of 

 other lands than those which discharged other sands into the ooliti- 

 ferous sea, and other modes of chemical or vital action in the sea ; yet 

 a scrupulous analysis of the oolitic system shows in its upper part 

 analogies to the cretaceous rocks so strong and so various as to render 

 it probable, if not certain, that the new conditions characteristic of 

 the new system were gradually or partially introduced till they entirely 

 predominated for greensanus alternate with the uppermost of the 

 oolitic limestones in the Alps, flinty nodules lie in the calcareous grit 

 and Portland oolite, and chalky limestones constitute the great portion 

 of the latter rocks in some situations of England. It is to be regretted 

 that we are so little able to determine upon good evidence what the 

 new conditions influential on the deposits of the cretaceous rocks 

 were ; for their effects are very similar along a great range of the 

 Atlantic coast of North America from New Jersey to the Mississippi, 

 and throughout the interior of Europe. 



The cretaceous period was not ended in England by dislocations 

 situated in or even near that part of the surface. In Ireland eruptions 

 of basalt of enormous extent cover the chalk, and indicate a crisis of 

 volcanic disturbance. In France, Elie de Beaumont refers to the 

 concluding part of the cretaceous period dislocations which range 

 north-north-west in the Jura, and travrrre the primary moss of Mont 

 Vim. After the chalk formation was completed in the south of 

 France the Pyrenees were uplifted to a great height, so as to limit 

 the tertiary basins of the south of France ; and it is supposed that at 

 the tame time the Apennines and the Carpathians experienced an 

 upward movement Conjecture hsa even joined to these the Allegha- 

 nies ; but it may be gathered from Professor Rogers' s reports on the 

 geology of America ('British Association Keporti'), and accordant 

 notices of Frathentonuaiigh and other competent geologist*, that an 

 earlier date should be allowed to that mountain range. [CHALK 

 FOBMATIOIT.] 



Tertiary Peri<xU.~ln general no contrast can be more complete 

 than that between the secondary and the tertiary stratified rocks : the 

 former retaining so much uniformity of character, even for enormous 

 distance*, as to appear like the effect of one determined sequence of 

 general physical agencies; the Utter exhibiting an almost bonndlrs* 

 local variety, and relations to the present configuration of land and 

 sea not to be mistaken. The organic bodies of the secondary strata 

 are obviously and completely distinct from those of the modem laud 

 and sea ; but in the tertiary deposits it is the resemblance between 

 fossil and recent kinds of shells, corals, plants, to., which first arrests 

 the judgment In general there is a decided break between the two 

 group* of rocks a discontinuity which is nowhere completely filled. 

 Y A, besides the pseudo-tertiary or transition chalky rocks of Maestricht 

 and the Pyrenees, and the conchiferous marls of Gosau, we hare in 



England and France above the chalk a prevalence of green and ferru- 

 ginous sands extremely similar to those below. Perhaps they !i.,-. > 

 been derived from the waste of these older rocks: Sir Charles I, yell 

 suppose* the tertiaries of the London basin to have been formed 

 from the waste of the secondary strata of Kent, Surrey, Sussex, and 

 Ham pah ire. 



With the tertiary system came into existence (if we may trust the 

 negative evidence which the earlier strata present) many races of 

 quadrupeds, some birds, reptiles, and fishes, extremely auul 

 though for the most part specifically distinct from the modern di 

 of laud and water; thousands of corals, shells, Criutaeea, &c., which 

 present with living races quite as great analogy as obtains !> ' 

 the tribes of the Atlantic and the Pacific oceans of our day ; tin- 

 general features of laud and sea as they now exist begin to appear, 

 and there can be no doubt that in a philosophical study of the revo- 

 lutions of the globe the tertiary era of geology cannot be properly 

 separated from the existing system of nature. 



Yet during the deposition of these rocks the relations of lui.l and 

 sea were greatly altered iu Europe by the rising of the I'yi 

 beyond the height they reached after the cretaceous era, and by the 

 uplifting of the Alps from the Mediterranean towards Mont lilanc. 

 In England we may believe the upward movement of the southern 

 counties, connected with the Hampshire axis of elevation and 1 1. 

 of Wight convulsion, was euded before the close of the tertiary period. 

 The eastern range of the Alps from Mont Blauc to Vienna is : 

 date, and may be viewed as the most marked phenomenon of elevation 

 which accompanied or preceded the dispersion of erratic rocks iu 



Europe. [TERTIARY StSTKM.] 



The following table, from Professor Ansted's ' Elementary Geology,' 

 gives a summary view of tha various strata of the earth, arranged 

 according to the latest authorities, and also gives tha foreign equiva- 

 lents of the various British rocks : 



Table of Clusiijicalion of Rockt. 

 TERTIAUY EPOCH. 



Foreign Equivalents or Synonyms, 

 and chief Foreign Localities. 



British. 



Modern Deposits : 

 liaised beaches . 

 Tent bogs 

 Submerged forests 

 Doposiu in caverns 

 Shell marls 



Newer Tertiary, 

 Series : 



or I'lioccnc 



1. Vppcr gravel and sand . 

 1. Till .... 

 :l. Mammalifcrous crag 

 4. Fresh vr.icr sand and 

 gravel 



J. Kcd crag . 



Middle Tertiary, or Miocene 

 Series : 



C. Coralline crag 



Lower Tertiary, or lioccnc 

 Series : 



7. I'luvio. marine beds 



8. Burton clnys . . . 



9. Bagshot and llracklcsham 



sand* . . . 



10. London clay and Boguur 



beds .... 



11. rhuler and mottled clays, 



sands, and shingles . 



Similar appearances in Northern Kuiopc, 

 Siberia, and America. 



These beds or their equivalents arc knoirn 

 in various part* of Northern 1 

 America. Other but very diHVrent de. 

 posits arc the newer beiU i-f 

 Others again arc found occupying a 

 large part of South America. 



Sutaappcninc beds. 

 r.iuwn coal (of Ucrmany}. 

 llclgian tertiaries (crag). 

 Tlie Mvalik beds (India) arc supj 

 belong partly to this period. 



PTouralnc and Itordeaux bed*. 

 Tart of the Molassc of Switzerland. 

 Vienna basin. 



Certain I .-iatic, North Aii u.m, 



and Noitll A met lean beds. 



Paris Basin. 



Onllnl France. 



Moluse of Switzerland (lower bed.-). 



Belgian tertiaries. 



Various beds in Western Ai-ia and Imli .1. 



Various beds in North and South Aim in a. 



Nutnmulilic beds. 



SECOKDA.IIT Krocii. 



Cretaceous System ; 



1.'. t ]i| cr chnlk nith (Unit 



.Ik without flinx 

 14. Ixjwer chalk and chnll 



marl . 

 13. 1'pper irriynsand . 

 10. Oault 



17. Lower greenund . 

 i. Kentis.i rag . 

 t. AthriHcId clay 

 Spec ton clay 



Scaglla li im tones of the Mediterranean. 



Maestricht 1...I-. 



M-Miiin.m elm-inn of D'Orbigny ((.'raie 



blanche). 

 Turonlan beds of U'Orbliiny, (Ciait 



tufallj ; <Juailrr.;niil-!rn, u! < .> rm.nn . 

 Altaian beds of D'Orbigny. 

 .J. <>! i ,. i many. 



. ,111 <>i M\ it/ei land and Krancc. 

 lliUthon of Germany, 

 i'ondicherry beds. 

 Bogota beds, South America. 

 (I) Aptun beds of U'Orbigny. 

 (!) lills-conglomcrat of Ucrmany. 



