IMAGE EVALUATION TEST TARGET (MT-3) 1.0 Li '- IIIIIM |50 '"" '- "■" 12.0 2.2 m 125 ! 1.4 1.8 1.6 i^. ^ Va ^ /}. / e". ei d^. % Photographic Sciences Corporation 23 WEST MAIN STREET WEBSTER, N.Y. 14580 (716) 872-4503 A"^ -b ^ nji V^ ^9) '^^ f^ \\ -^"U ^ *> « 4 * • ' - • . » . •• • . • «... ••,••«..- uje 'i. MAP TO IM.I.HTKATK THE RELATIONS 01" GEOLOGY TO AGRICULTURE I» NORTII-E ASTERN AMF.llICA. St. Jdkn's River. SuJol^n^^" Soils S». 1. .vud U. liiiiiji s'/7^/mr/r/^— The' cxmnplcs ol' a cK.sc ro hifion hotwccn .ireolojric al structure and air,-ic„lturnl (•.-.pahilitv wl.jcli 1 introduced into the prcccdin- part of this paper,* were mterostino: to the Kn-lish reader chiefly in their purely scientific ami economical bearin-s. Relerrin- to the Atlantic border of the United States, and to the interior of the State of New Vork, they would come home, if I niaj so ex])ress myself, to few amon-' ourselves as a matter of directly personal concern. It will he somewhat dffTerent as re-ards the exam])le I am now ab.)ut to submit, Jt IS drawn from one of our own Rritish provinces, where many of us have friends and relatives, and where wide unoccupied lands exist, to which we may emi-rato witliout either abandoning our loyalty or ^{yiivr ui) our connexion with :lie homes of our fatliers. The province of New Brunswick contains an area of 18 mil- lions ol acres; much of this is still covered with forests, and many districts still unexplored even by the lumberer. As repre- sented in the ^eolojrital ma])s hitherto published, its central part forms an extensive coal-field, boumh^d on tiie north by a riband <)1 granitic and of old metainorphic and slate rocks, which runs diajronally— or m a mntli-east and south-west direction— across the wliole province. On the south and south-west it is bounded along the shores of the Bay of Fuudy by a belt of slate ro.ks of uncertain age, altered and hardened by extensive masses of hard, intrusive trap, which give an inhospitable and uninvitin- cha- racter to the region ovc^r which they extend. This coal-field occupies about one-half of the whole area of \«nv Brunswick • and, as it is situated in the central part of the province, the rocks' * Sec this Jouiiuil, vol. xiii. Part I. I! 2 MAP TO IlMIgTllATE THP RELATIONS OF GEOLOGY TO AGRICULTURE tM NOllTII-EASTERN AMEllICA. St. John's River. St. Jolin^ ^^ Soils Xo. I. and II. mn. Soil . . No. III. I^^l Soil . . No. IV. ^Pi Soil . . No.V. ] Bogs and Swamps . I^f|§-'1 S C A L K OF M 10 5 10 To face piKje 3. HAY I't: CIIAI.KIUS. 4 Rehtions of Gcohn/}/ tn Af/ricuUnrc of which it consists impart tlicir prcvailinjj; physical charnctcrs to the soils of this laijjc portion of the colony. It may be said uitli truth that tlic extensive prevalrnre ol this coal-lield in \e\v r.nnis\vi( k forms ah.ue a strikinj; illustration of the close natural (onnexJon wliich exists between }j<'oloj;i< al structure and a«iricidtural ( inability. Of <'very cxtenbivo (oal- fieid tliis mijfht, to sonu; extent, be said ; but there are two • ircumstances in tonnexicm with th(« coal meas\uvs ot New Hrunswick, which in an espec ial manner determine the agricul- tural relations of the soils wiiich rest upcm them. 'I'he first is the chemical nature of the nun\erous beds of rock of whi.li tliis coal formation consists. 'J'hesc are, for the \\\oj,i part, \ixvy sandstcmes, sometimes dark and greenish, and some- times of a pale-yellow colour. The siliceous matter which they c«mtain is cenu'nted together or mixed with only a small propor- tion of clav (deiav^'d' felspar principally), so that when these rocks crund'de, wliich thev readdy do, they form light sods, pale in colour, easily worke(., little retentive of water, admitting therefore of being ph/ughed early in spring and late in autumn; l)ut hungry, greedy of manure, liable to be l)urnt up hi droughty summers, and less favourable for the production of successive crops of hay. • i , • i Of course, among the vast number of beds of varied thickness which come to the surface in dlfl'ercnt p.arts of this large area, there are many to which the aboAc general description will not appl}— some which contain more clay and form stiffer soils ; and some which, though green or gray internally, weather ol a red colour, and form reddisli soils : but lightness in texture and in cohmr forms the distinguishing characteristic of the soils of the whole formation. The generalization drawn from this single fact, therefore, gives us already a clear idea of the prevailing physical character of the soils over a large portion oi the pro- vince, and illustrates the nature of the broad views which make the possession of geological maps so valuable to the student of general agriculture. , i v. i In other countries, as in England and Scotland, the coal measures omtain a greater variety of rocks than is found oyer the carbcmiferous area of New T^runswick. They arc distm- giiished in our island by the frequent recurrence of beds of orrk- coloured shale, often of great thickness, which form cold, stiff, dark-coloured, ])o(n- clays, ^ard to work, and, until thoroughly ral piiysiral conformation. It \i thstiuijiiishcd l)y a {jcnf?ral flatness ol' si:rl".ico: it undul-itos Icrv* and there, indeed, and is intersected l>y rivers and occasional h-tkcs ; hut it consists lorth;; most part ol" tahh'-lands more or less elevated, over which forests, ciuelly of pine-timher, extend in every direction. This gener;il flatness is owin;,^ to the small inclination of the sandstone strata on which the country rests, and to tlie small numlxr of strikin!;; pliysical distuihanc(!s to which, as a wlude, they 1 ave been suh- jected. Tiiesc level tracts of land are not unfrequently stcmy, covered with blocks of fi^rey sandstone of various sizes, amonij; which the trees jj^row luxuriantly, and from nmonu^ which the settler may reap a first crop of corn, hut which almost defy tiie labour of man to bring the land info a fit condition for the j)loug!i. It is chiefly on the borders of the coal-field, however, that these ston; iracts occur, as if the disturbances, to which the neigh bourin.'j;' rocks have in many places been •^ubjected, had broken up the edges of the sandstone strata, a: A '< c+tered their fragments over the adjoiiiing surface. A characteristic feature which results from this physical flat- ness is the occurrence of frequent bogs, swamps, cjirriboo plains, and sandy barrens. The waters which fall in rain or accumulate from the mcdted snow rest oi the flat lands, fdl the hollows, and, for wrnt of an outlet, stagnate, causing tlie growth of mosses and of plants of various other kinds, to which such swampy places are jnopitious. Thus bogs and barrens, more or less extensive, are prvxluced., and these greatly modify the natural agricultural relations of the sur^^ace. Thus the geological age, the chemical composilicm, and the physical disposition of this coal region, in reality appear almost equally to conspire in producing the peculiar general agricul- tural character of the central half of the province of New Bruns- wick. To this conjoined influence of important modifying causes I shall again advert before the close of the present article. But J\ew Brunsv/ick also presents exam})les of the most striking and immediate dependence of agricultural value upon geological structure alone. On the outskirts of the coal field, and rising up from beneath its edges, appear red sandstones and|red conglomerates, associated with limestones, red marls, and gypsum. These give rise to soils of a remarkably fertile cha- racter, in the midst generally of .scenery of a most picturesqu*! description. In such localities rock and soil so close'y accompany each other, that the most sceptical is compelled to admit that t!ie 1 6 Relations of Gcoloi/ii to Af/ricultinc &: change in forest trees, in character of soil, and in nature of rock, arc at once siniultaneous and determined by a common cause. Tlie foHowing section (No. I.) gives an idea of the w.'iy in which tliese rocks occur in connexion with the coal measures, and ' the kind of soils which they res})ectively form : — The section commences cm the left with the tran nnd altered rocks which J bound the coal-field towards the south, i as at the head ol Belleisle bay, or 1 on the Hammond river, about twenty f miles from the town of St. John. On these rocks scanty soils are found, and the gloom of the narrow-leaved >, forest is rarely broken by the intrusion & . of the more cheerful beech, the oak, or I c the niaple. But (m the rounded hills £| of the red c:onglomerate (1), — which in |§ Albert county remind the luiglish tra- ^> veller of the hills of our own Monmouth- 3 sliir(? — I)road-leaved forests of various trees cheer the eye, while the free and ^ ojx'n soils which rest on them, tliough I sometimes too gravelly, yet admit of being ■| (ultivatcd along steep slopes till the S \\aviug corn crowns the very tops of the hills. In the beautiful Sussex vale — justly the boast and pride of the pro- vince — and in some of its tributary val- leys, the eye recognises with pleasure the fi-aturcs, both physical and agricul- tural, which *re familiar in the red sandstone slopes of Strathmore, in the richly-farmed red sandstone fringe of I Sutherland, and wl>ere a tillage hardly to I be surpassetl crowns the hills of VVool- '- ler, and ac( oijij)anies the N()rthund)rian tourist to the foot of the Cheviot hills. Over the red c . ' 2nd. That the ptiysical structure of a country Jias niu.ch. in- fluence in causing the production of such diversities of soil upon^ or from, the debris of rocks of the same age and kind. 3rd. That the existence of flat table-lanjs; for example, ox of depressions having no natural outlet, will cover extensive portions of such a surface with swamps and bogs, in' cliraates. which favour the accumulation of vegetable matter. Thu^, u« in Ireland not less extensively than in New Bruns\v4ck, the econo.mico- agricuHural influence of geological structure may be disguised or wholly hidden by the purely su])erficial covering of decaying, vegetable matter. 4tli. That, generally speaking, the soil of a district of uniform geological character will improve in the direction of the natural drainage and river outfalls. Wliere rains fall or snows melt, it is the tendency of the flowing water to enrich tlie lower at the ex- }>ense of the higher country, and thus to establish differences of soil which did not originally exist. At the same time the final result of such action will depend very much upon the nature 16 Relations of Geolof/i/ to Agriculture of tlio rocks tlinnsclvos. If tlicy consist of limestone, the r.-ins may wash down tlio finer particles from many i)laees ; hut wherever soil nunains it will still retain nearly the same com- position as at first, and will be little impaired in fertility by the action of the rains. Henc(! the fine sweet herhajro whu h clothes our limest(>ne-hills, and makes them so j;rateful to the pasturing; Hocks. Or if hills or table-lands of red marl* form the hi<;her country, portions may be washed down without materially affect- ing the quality of what r(Mnains. Let a fresh portion <)! the n)ck crum])le, and thinirs are a-ain as they were before. A new soi is produced, equally fertile with that which has been washed away, and thus the fertility natural to the rock will be perma- nently maintained. It is different, however, in the case of sandstone ro-ks, such as those of the coal-fields of New Brunswick. When such rocks crumble they form soils more or less sandy, according to the pro- portion of fine clay which has been originally ccmtained in the materials from which the rock was formed. Now, the action ol hi., y rains upon such a soil is not to carry it away bodily, as in the case of the limestone or of the fine red marl, but to wash out the fine clayey particles, and carry them down to lower levels. Thus on the uplands the sandy soils become every day more sandy and of less value, while, in the direction of the drainage, they become, on the other hand, constantly more tenacious and productive. • i i • Thus the amount of infiuence exercised by physical thainage is itself limited, and determined by the chemical composition oi the rocks of which the country consists. 5th. That the passage of rivers or of sea-arms across a poor fountry, after it has previously traversed a richer geological region, is sure, to a greater or less extent, to modify— to increase, in fact, the value of the surface in the line of its course. 1 Iuk is seen, as I have pointed out, on the St. John river, and at the head of the Bay of Fundy, and is confirmed by observations made by myself and others in nearly all parts oi the world. Gth. That partial elevations of the Innd at successive periods will aid otlier physical causes in establishing such differences, often, as in New Brunswick, covering with more fertile land the surface which has been most recently raised from beneath the waters of seas or lakes. It is conceivable, however, that in other conditions the very converse may take place. These practical results are drawn directly from the map before us. Of course they do not indicate or exhaust all the causes by whicii modifications are introduced into the agricultural indications ot * Sucli us is rt'prese' 'i» <-»ui sections l)y (a). in North- Eastern America. 17 pure gcolofjy. A siir.llnr annlysis of other oxnmplcs will in('irencies? In what way and to what extent have climate, physical structure, recent chanjjes of physical structure, the neifjhbourhood of unlike p^eological formations, the action of those induences which produce what geologists call changed or metamorphic rocks, or other natural causes, been instrumental in producing such modifications? This, like all other more ad- vanced inquiries, is more complicated and difficult than the simple proldcm of the direct relation between the character and age of a rot k, and the quality of the soil it produces when broken up. B t it will result in furnishing us with Sj^ecial surface maps, waich will be of direct and immediate use to the practical agriculture of every country. And, what will be not less in- teresting, theoretically, it will at once connect these soil-maps with our strictly-geological ernes, through the intermediate agency of physical causes, similar to those which have operated in a greater or less degree at all geological epochs.