.36 



THE FARMER'S MONTHLY VISITOR. 



Geology of Maine. 



BY ClIARLKS T. JACKSON, M. D. 



Geological origin^ distribution^ chemical composi- 

 tion and capabilities of soils. 



Considering' the vital importance of a correct 

 knowledjrc of the science and art of agriculture, 

 upon which man depends for liis daily bread, we 

 shall willinijly avail ourselves of any information 

 that may throw light upon the principles, by which 

 we are to be nruided in practical operations. 



It cannot be concealed that agriculture in this 

 country is far below the standard attained in Eu- 

 rope, and that by their more scientific methods, the 

 Frencii, German and Italian farmers are enabled to 

 raise larger crops, so as to supply us with many ar- 

 ticles of agricultural produce, at a lower rate than 

 we have been able to grow them upon our own soil, 

 and this too has been effected by people whose soil 

 costs vastly more than ours. 



It is well known, that for several years past, large 

 quantities of wheat, barley, Indian corn and beans, 

 have been imported into this country from France, 

 Germany, Vcnitian Lombardy, Tuscany and Egypt, 

 while at the same time, orders have been sent out 

 from France for the purchase of our refuse bones ; 

 and the bone black of sugar refineries — substances 

 used in that country for improving the soil. Thus, 

 strange as it may seem, the French farmers send 

 out to this country for manure, and supply us with 

 bread, while many remain ignorant of the value of 

 those very substances so eagerly sought for by our 

 foreign brethren I 



European science has been brought to bear upon 

 tlie art of agriculture, and hence the improvements 

 are rapidly progressing there; while we have as 

 yet done but little towards the development of this 

 most important of arts. 



I know that many intelligent farmers decry "book 

 farming" as useless, and tlicir remarks are certain- 

 ly worthy of our attention, and we may perhaps 

 remove their objections. Good books on this sub- 

 ject record the experience of many excellent prac- 

 tical farmers, and concentrate all the informa- 

 tion that is scattered in various parts of the world; 

 Ti'hile at the same time they give general rules by 

 •which we are to be guided in practice. Where 

 then is the objection that has been raised against 

 such knowledge.'' It will be found that there are 

 few such books in existence, although there are 

 materials enough on record to furnish a good trea- 

 tise, and those books that have appeared, are defi- 

 cient in some of the most essential particulars, or 

 they are so technical that those who are unacquaint- 

 ed with the elements of science cannot understand 

 them. There are also imperfections in the certifi- 

 cates and rules, owing to no analysis having been 

 made of the soils in question. 



So also our own farmers are unacquainted with the 

 composition of their own soils. Hence we account 

 for the uncertainty of the results obtained by those 

 who make trials of new methods of farming, and 

 we ought not to be surprised at their frequent fail- 

 ures. 



If, however, all the conditions of the problem 

 were understood by both parties, farmers would 

 readily join hands with their scientific co-laborers, 

 and tlie art of agriculture would soon become as 

 certain as any other art, while, by the application 

 of scientific principles, the business would become 

 of a more exalted charactor, and assume its true 

 rank in the consideration of all men. 



In order to make rational experiments in farming, 

 it is essential that the composition of the soil should 

 be known, and then wg can act understandlngly in 

 our operations. In order to amend a soil, that 

 knowledge is absolutely necessary, otherwise we 

 might destroy its fertility, by the processes intend- 

 ed for its amelioration, and thus be subjected to dis- 

 appointment and chagrin. 



Mineralogy, geology and chemistry come to our 

 aid, and serve to indicate the nature of the various 

 soils, while sure indications are readily discovera- 

 ble for the amendment of those which are sterile. 



Agriculture is of so great importance to the com- 

 munity, that we should not allow our knowledge of 

 it to rest upon mere empyricism. It oughi. to be 

 exalted to the rank of a true science, and then it 

 will become one of the most honorable, as it is one 

 of the most useful of arts, and even the most high- 

 ly educated men will then be proud to rank as 

 scientific farmers. 



Let us now examine the subject more in detail, 

 and ascertain how much light we may obtain from 

 the science of geology, that jnay serve to guide us 

 in our researches. 



We have first to consider the geological origin of 

 soils. 



Every attentive person must have observed, that 

 solid rocks, exposed to the combined action of air, 



water, and different degrees of temperature, under- 

 go decomposition and disintei^ralion, so that they 

 crumble into powder, and that some rocks decay 

 more rapidly than others, owing to their structure, 

 or mineralogical composition. If a rock is porous, 

 or stratified in its structure, water infiltrates into 

 it, and on freezing, expands with such power, as to 

 tear the surface of the rock to pieces, so that it rea- 

 dily crumbles. When fire runs through the for- 

 ests, it heats the surface of the rocks, and by the 

 irregular expansion produced, they are shivered in- 

 to fragments. 



The action of running water and friction of 

 stones, also serve to grind the rocks into powder, 

 by attrition of their surfaces, and the detritus is 

 borne along by the streams, and deposited in low 

 lands, or along their borders. 



When a rock contains iron pyrites, or sulphuret 

 of iron, that mineral, by tiie action of air and wa- 

 ter, decomposes, and forms copperas, or sulphate of 

 iron, and the sulphuric acid of that substance acts 

 powerfully on some of the ingredients of the rock, 

 and causes its rapid decomposition. Any person, 

 who has been on the Iron Mine Hill, in Gardiner, 

 will fully understand how rapid Is this operation, 

 and may there see its results. The oxidizing pow- 

 er of the atmosphere, also, acts powerfully upon 

 the surface of those rocks, which have for one of 

 their components, the prot-oxides of the metals, 

 iron and manganese, and as those oxides take up 

 another portion of oxigen, they increase in bulk, 

 become brown or black, and the stone falls into 

 fragments. 



These are a few of the causes now in action, 

 which modify the solid crust of the globe, and it 

 appears that their effects are far more important, 

 than we might at first imagine. Whoever looks 

 upon the muddy waters of the Mississippi, Ganges, 

 Po, the Rhine, and the Rhone, or reads the calcu- 

 lations respecting the enormous quantity of matter 

 brought down from the mountains by those rivers, 

 will at once appreciate the modifying influence of 

 those causes which are continually wearing down 

 the solid matter that forms the mass of our moun- 

 tains. 



Geology teaches us, that such causes were for- 

 merly in more powerful operation, and that the an- 

 cient world was, from its infancy, subject to vio- 

 lent catastrophes accompanied by powerful inroads 

 of the sea ; oceanic currents and tumultuous waves 

 having for many successive periods rushed over the 

 land, and beaten the loftiest crags of the highest 

 mountains. We should then naturally expect, that 

 the earth would present ample testimony of the ac- 

 tion of these powerful causes of disintegration of 

 the rocks, and we do observe that a large portion 

 of the loose materials upon the surface, bear proofs 

 of aqueous action and mechanical abrasion. By 

 thos« ancient convulsions, the detritus of the solid 

 rocks was prepared, and forming the various soils, 

 which we observe, the earth was rendered capable 

 of yielding its rich stores of vegetation, on which 

 a large proportion of the animated creatures de- 

 pend for their food. From the foundation of the 

 everlasting hills, the Creator, began to prepare 

 the world tor the habitation of his noblest crea- 

 ture, man, and converted a portion of the solid 

 rocks into soils, which were given as the field of 

 human labor, and to the progenitor of our race it 

 was commanded that he should till the soil. 



If we take up a handful of earth, and examine 

 it attentively, we shall readdy discover such min- 

 eral ingredients, as denote the rocks from which it 

 originated. Thus we discover in a soil numerous 

 spangles of mica, grains of quartz, and white or 

 brown earthy looking particles, which are felspar ; 

 besides which, we remark a considerable portion of 

 fine brown powder, which being examined with a 

 microscope is found to be composed of the same 

 minerals, more finely pulverized, and mixed with 

 the brown oxide of iron. It will be at once under- 

 stood, that such a soil arises from the disintegra- 

 tion and decomposition of granite rocks, and that 

 the oxide of iron was derived from the pyrites, or 

 the prot-oxide of iron, contained in that rock. 



A soil arising from the decomposition of gneiss, 

 possesses similar characters, only the mica is 

 more abundant. 



aoils from mica slate are made up of a large pro- 

 portion of mica, mixed with grains of quartz. 



Sienite, and hornblende rock, produce a dark 

 brown soil, in which there is but little quartz, and a 

 i^reat deal of feldspar, and decompo.sed hornblende. 



Greenstone trap-rocks form by their decomposi- 

 tion a brown soil, which contains pieces of the un- 

 decomposed rock, but the component minerals in 

 the soil itself, are rarely so distinct as to be discov- 

 erable. This soil is a warm kind of loam, soft 

 and spongy, easily compressed into smaller dimen- 

 sions by the pressure of tho hand, but not adhesive 



like clay. It is peculiarly adapted to the growth 

 of p-'tatoes, and is a luxuriant sod for most of our 

 ordinary produce. 



Slate-rocks forma soil of a blue color, in which 

 numerous undecomposed fragments of the rock 

 may be discovered. When transported by water, 

 it is deposited in the state of tough blue clay. 



Limestone forms various colored soils, according 

 to the nature of the impurities it contains. They 

 are generally of a light yellowish brown color, from 

 admixture of a certain proportion of oxide of iron. 



This is especially the case with those soils deriv- 

 ed from the argillo-ferruginous limestone. 



Calcareous soils, if they are rich in carbonate of 

 lime, may be distinguished by their effervescence 

 with acids, and the quantity of this siibstance may be 

 estimated by the loss of weight which indicates the 

 proportion of carbonic acid, that has been expelled, 

 and since the carbonic acid always occurs in the ra- 

 tio of nearly 44 per cent, to 5G per cent, of lime, it 

 is easy, by a proportional calculation, to ascertain 

 the quantity of that mineral in the soil. 



It more frequently happens, that there is so mi- 

 nute a quantity of carbonat, of lime in the soil, as 

 to require a minute chemical analysis for its detec- 

 tion, and few farmers have either leisure or means 

 for such an operation. Examples of such analy- 

 ses will be presently laid before you. 



Talcose slate rocks, when decomposed, form a 

 light brown soil, in which particles of the rock are 

 discoverable, and on analysis, a considerable quan- 

 tity of the silicate of magnesia is found, which is 

 one of the chief components of talc. 



Red sandstone, on disintegration, forms soil com- 

 posed almost entirely of grains of quartz, with ox- 

 ide of iron, and clay, with a few spangles of unde- 

 composed mica. 



Grau-wacke, or conglomerate, when disintegrat- 

 ed, produces a light grey soil, full of smooth rounded 

 pebbles, which originate from the undecomposed 

 components of the rock. 



Red porphyry is very slow of decomposition, and 

 forms a bright red fine powder, filled with angular 

 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 vari- 

 ous 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 de- 

 pend upon their situation. 



In various sections of this report maybe seen re- 

 corded the proofs of diluvial transportation of rocks, 

 far from their parent beds, and we have every rea- 

 son to believe, that this removal was effected by a 

 tremendous current of water, that swept over tho 

 State from the North 15 d. West, to the South 15 

 d. East, and we have adduced in testimony that 

 such was the direction of the current, numerous 

 grooves, furrows or scratches upon the surface of 

 the solid rocks, in place, and have shown conclu- 

 sively, that the rocks which we find thus transport- 

 ed, proved to be portions of ledges situated to the 

 North of the localities where their scattered frag- 

 ments 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 reflect 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 ICtaidn, 

 it is proved, that the current did rush over the sum- 

 mit of that lofty mountain, and consequently 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 increas- 

 ed by its enormous pressure. 



It will be readily conceived, that if solid rocks 

 wore moved from their native beds, and cj.rrled for- 

 ward several miles, that the finer particles of soil 

 should have been transported to a still greater dis- 

 tance, so we find that the whole mass of loose 

 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 was ev- 

 idently derived from those ledges which occur to 

 the Northward. 



If an attentiva observer examines th» soil in the 



