1838] 



FARMERS' REGISTER. 



249 



It more frequenlly happens, that there is so mi- 

 nute a quantity orcarbonate of lime in the soil, as 

 to require a minute chemical analysis lor its detec- 

 tion, and lew liirniers have cither leisure or means 

 Cor such an o|ioraii()n. lOxamples of such analy- 

 ses will be presently laid before j'ou. 



Talcose slate rocks, when decomposed, form a 

 li^lit brown soil, in which particles of the rock are 

 discoverable, and, on analysis, a considerable 

 quantity of the silicate of magnesia is found, 

 which is one of the chief com[)oiient3 of talc. 



Red sandstone, ordisintejiralion, Ibrms soil com- 

 posed almost entirely of irrains of quartz, with 

 oxide of iron, and da}', with a few spangles of 

 undecnmposed mica. 



Grau-wacke, or conglomerate, when disinte- 

 grated, produces a lif^ht ^ray soil, full of smooth 

 rounded pebbles, which originate from the unde- 

 com posed components of the rock. 



Red porphyry is very slow of decomposition, 

 and fjrms a bright red fine powder, filled with an- 

 gular fragments of the rock. 



I have thus distinguished and described the ap- 

 pearances which characterize those soils that arise 

 immediately from the decay of solid rocks, and 

 various characteristic specimens of each variety 

 may be seen in the cabinet arranged for the use 

 of the state. 



Let us next consider how soils are distributed 

 on the earth's surface, and see how their qualities 

 depend upon their situation. 



In various sections of this report may be seen 

 recorded the prools of diluvial transportation of 

 rocks, jar from their parent beds, and we have 

 every reason to believe, that this removal was el- 

 fecled by a tremendous current of water, that 

 swept over the state frum the north 15° west, to 

 the south 15" east, and we have adduced in testi- 

 mony, that such was the direction of that current, 

 numerous grooves, furrows, or scratches upon the 

 surface of the solid rocks, in place, and have 

 shown conclusively, that the rocks which we find 

 thus transported, proved to be portions of ledges 

 situated to the north of the localities where tlieir 

 scattered fragments are found. 



it is a matter of surprise, that such enormous 

 masses of rock should have been moved so far by 

 an aqueous current ; but, when it is remembered, 

 that a rock does not weigh but half so much when 

 immersed in water, as it does when weighed in 

 air, owing to the support given it by the water 

 around ; and when we reHect on the fact, that a 

 rock is still more powerfully supported under the 

 pressure of deep water, it may be conceived, that, 

 if a flood of water did once rush over the land, it 

 might have removed large and weighty masses of 

 rock, such as we find to have been the case. 



From the observations made upon Mount 

 Ktaadn, it is proved, that the current did rush 

 over the summit of that lofty mountain, and con- 

 sequently, the diluvial waters rose to the height of 

 more than 5000 feet. Hence we are enabled to 

 prove, that the ancient ocean, which rushed over 

 the surface of the state, was at least a mile in 

 depth, and its transporting power must have been 

 greatly increased by its enormous pressure. 



It will be readily conceived, that if solid rocks 

 were moved from their native beds, and carried 

 forw^ard several miles, the finer particles of soil 

 should have been transported to a still greater dis- 

 tance, so we find that the whole mass of loose 



Vol. VI.— 32 



materials on the surface has been removed south- 

 wardly, and the soil resting upon the surface of 

 rocks, in place, is rarely, if ever, such as results 

 from the decomposition of those rocks, but waa 

 evidently derived li-om those ledges which occur 

 to the northward. 



If an attentive observer examines the soil in the 

 city of Portland, he will discover, at once, that it 

 is made up from the detritus of granite and gneiss 

 rocks, while the ledijes in that city are wholly 

 composed of the argillaceous, talcose, and mica 

 slate-rocks, and granite and gneiss occur in great 

 abundance to the northward. 



All the markings on the surface of the rocks, 

 and the scattered boulders of granite and gneiss, 

 which abound in that soil, indicate its origin to 

 have been in the north 15'^ or 20° west. I merely 

 quote the above locality, on account of its being a 

 spot where most persons will have occasion to ex- 

 amine the facts stated. The various sections of 

 the state present ample illustration of the same 

 fact, and every one who will take the trouble, 

 may convince himself of its reality. 



The tertiary deposits of clay, sand and marine 

 shells, were evidently produced in tranquil water, 

 since their strata indicate, by their situation, struc- 

 ture and beds of shells, that the clay was gradu- 

 ally and slowly deposited, allowing time lor the 

 propagation and growth of the various shell fish 

 in its several layers. Not so was the diluvial 

 matter deposited, for we find it to bear marks of 

 sudden and violent transportation and deposition, 

 the various pebbles, boulders and erratic blocks of 

 stone being mixed in great confusion. I have 

 formerly mentioned a locality, in Bangor, near 

 the court-house, where, it would seem, there are 

 proofs of a gradual subsidence of the diluvial cur- 

 rent, the various particles becoming smaller, as 

 we ascend the embankment, until we come to fine 

 clay, which must have subsided from tranquil 

 water. 



We observe, then, that the tertiary deposits 

 were cut through by the diluvial waters, which 

 have excavated deep valleys, and heaped up long 

 ridges called horse-backs, and the general direc- 

 tion of these valleys and ridges, coincides with 

 the direction formerly indicated, as the course in 

 which the current swept. 



Although we are informed in the scriptures, 

 that the deluge was ordained for the punishment 

 of wicked men, it is certain, that there was mer- 

 cy mingled with this dispensation, for the soils 

 were comminuted, transported, and mixed in such 

 a manner, that their qualities were improved, and 

 rendered more si:iitable lor the growth of plants, 

 so that new and more fertile soils were prepared 

 for coming generations, who literally reap advan- 

 tage from the deluge. 



Besides the ancient aqueous current, we see 

 every day the action of water modifying the sur- 

 face of the globe, transporting fine particles from 

 the mountain-side, and depositing them in the 

 valleys and along the margin of running streams. 

 Especially during freshets, when the rivers burst 

 their narrow confines, and spread out over the in- 

 tervales, do we see rich deposits formed of allu- 

 vial soil. 



Such currents, arising amid decomposing vege- 

 table matters, transport an infinity of fine particles 

 of such matter, and deposit it with the various 

 earthy ingredients, which form our richest mea- 



