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The study of organic remains, which has hitherto been much neglected by geologists, to the great injury of the science, affords our author some arguments on a subordinate question, though one of very great interest, which is yet sub judice. Werner and his disciples maintain that the strata found in inclined and vertical positions were so deposited, and do not owe their present situation to any subsequent change. Saussure was of this opinion, until he observed the vertical strata of pudding-stone in the Valorsine. A chemical precipitation on crystallization may be supposed to produce rocks in any position indifferently; but in the mountains in question immense perpendicular beds contained stony masses of great size and weight, which had been rounded by the mechanical action of water. It was difficult to imagine that strata consisting of these huge masses were formed in a vertical position; they must have been originally horizontal, and thrown subsequently by some force, probably acting from the centre of the earth, into the situation they now occupy; and the same con→ clusion must be applied to the tabular masses of granite with which they are in conformable position, and must be extended to the vast ranges of the Alpine mountains.
Mr. Townsend produces a strong argument of a similar character from the position of shells, &c. in rocky beds, which now Occupy a perpendicular position. Vast quantities of these shells lying flat in the direction of the strata prove that they subsided horizontally in the bosom of the ocean. In his section on the dislocation of strata, he brings to view a large body of facts, which clearly evince the surface of the earth to have undergone, from agents of one kind or other, most extensive disturbances and
On the second great geological question, which concerns the elevation of continents above the surface of the ocean, our author coincides in their general position with the Huttonians, although he does not agree with them in every particular. The difficulties may be considered as nearly equal on both sides. It has perplexed all the ingenuity of the Wernerians to discover what has become of the immense volume of water which once covered and stood so high over the whole earth. On the other hand, it is equally hard to imagine a power sufficient for the elevation of whole continents from the abyss. We are, however, in possession of more facts which lead to this alternative than to the other.
With respect to the origin of the two classes of rocks which the Huttonians adopt as the instruments of their operations, Mr. Townsend takes a middle course. He fully allows the aqueous origin of granite, and considers it as the oldest of the deposits of the ocean with which we are acquainted; but he attributes
basalt to volcanic agency. "Considering," says he, " by the statement of this distinguished mineralogist (Mr. Jameson) veins of basalt traverse granite, gneiss, micaceous schist, mountain lime-stone, coal, and most of the floetz rocks, and contain rolled pieces of quartz, gneiss, hornblende, and other fossils, I am inclined to class this rock, not only with amygdaloid and pumicestone, but with lava."
He endeavours to point out a general connection between hot springs, volcanic phenomena, earthquakes, and the vicinity of granitic mountains; and it must be confessed that his opinions on this head are fully established by a series of surprising phenomena observed by Humboldt in the new world. It appears that the whole granitic chain of the Cordilleras, which form the foundation on which the continent of South America may be said to repose, is one immense series of volcanoes. The phenomena observed in this wonderful country are almost sufficient to reconcile us to the hypothesis of the volcanists. We shall quote some of the facts which our author has selected.
"Between Cotopaxi and the Southern Ocean, Humboldt reckons 40 volcanoes constantly burning.
"In the Andes we find Antisana, whose height is 19,300 feet, and in which the grand eruption of 1590 has been particularly noticed. "About the same time Aconcagua, rising 15,600 feet, poured forth its lava.
"Cayambé Ourcon is 19,392 feet high, and is a volcano, but the period of its eruption has escaped observation.
"Cargavirazo was burning furiously in 1698, and has been measured. It is 15,680 feet high.
"Sinchoulagoa broke out at the same time with Pichincha, A. D. 1660. It rises 16,456 feet.
"Besides these many others have been transiently mentioned by our voyagers, but neither their height nor the time of their eruption has been specified.
"Humboldt, near Popayan, visited one volcano at Pasto, and an other on Purace, which throw out water. He is of opinion, that the whole province of Quito is only one volcanic mountain, whose craters appear in the lesser mountains of Cotopaxi and Pichincha and communicate in the depth beneath.
"At Pichincha, lying prostrate on a flat rock, which hung over the mouth of the volcano, he looked down into the throat, which is about one league in circumference. In this he took notice of many mountains, whose summits appeared to be 300 toises beneath him, and he conceived that the bottom of the crater might be on the same level with Quito. He smelt sulphuric vapour, saw blue flames, and almost every minute felt the tremor of the stone on which he lay." (P. 353— 355.)
"Chimborazo rises 21,440 feet over a great gulf of fire," (P. 355.).
But the most astonishing phenomenon occurs in the five peaks of the great volcano Jorullo, of which Humboldt has lately given so interesting an account.
"Stretching from west to east, they extend from Colima to Orizaba, from the Pacific Ocean to the Gulph of Mexico. These rise highest towards the east, and the chain seems to have originated far from land, in clusters of islands, covered with pumice-stones, in the Pacific Ocean.
"From this circumstance Humboldt conjectures that there exists a chasm, running east and west, for the length of 137 leagues. In confirmation of his opinion we may observe, that north of this range hot springs abound, and that from 18° to 22° there is nothing but basalt, amygdaloid, and porphyry.
"Of these volcanoes, Jorullo or Xorullo, pronounced Horuyo, demands particular attention. It first appeared in 1759, and at the same time thousands of volcanic cones were thrown up, from which issued subterranean noises. In the midst of these six large masses rose 1640 feet out of the chasm, extending from N. N. E. to S. S.W." (P. 356, 357.)
We cannot go through the whole series of these observations; but must content ourselves with recording the inference which Mr. Townsend obtains from them.
Having thus cleared my way, I may proceed to state, that the whole western coast of America, from Terra del Fuejo to the northern extremity of Mexico, is indebted for its present relative elevation to the agency of fire, may be conjectured on the subsequent grounds. 1. The Andes, in their whole extent from north to south, show the presence of volcanoes, and appear to be the great storehouse of subterranean fire. 2. They are extremely elevated above the surface of the sea, and the adjacent ocean is extremely deep. 3. They are evidently dislocated, and exceedingly abrupt. 4. The strata, once horizontal, now dip from the Andes eastward into the Atlantic Ocean, and on the eastern coast the water deepens slowly, that is, about one fathom in a mile, as appears by sounding.
"Now as fire, an agent of unlimited power, is visibly at hand in the very spot where a great effect has been produced, and as no other agent adequate to such an effect appears-may we not be permitted to conjecture, that volcanic fire has been the cause of this elevation? If so, then Strabo will appear to have been right in his conjecture respecting the production of islands, and warranted in his conclusionif islands, why not continents?-Dislocation every where appears, and the powerful agent in question has every where been traced." (P. 368, 369.)
Our author has indeed traced phenomena similar in kind, though not so extensive in their present operations over a great portion of the earth's surface. The appearance of several islands above the sea since the period of authentic history is well known, and a multitude of facts are recorded which prove that the cause
producing earthquakes exerts its influence at vast distances, and therefore must be situated at a great depth below the surface.
"In the year 1755, when the great earthquake happened, by which every part of Europe and all the north of Africa were shaken, and Lisbon was destroyed, Loch Lomond in Scotland was observed to be in a state of uncommon agitation, without any apparent cause. In Loch Tay such a phenomenon is not unusual when every thing around is calm. The same frequently occurs in the Lake of Geneva, which suddenly ebbs and flows, when there is not a breath of air to agitate its surface. The cause, therefore, must be internal, and may be sought for in the agency of subterranean fire." (P. 360, 361.)
On the whole, we believe the volcanian hypothesis will gain much by the collection of facts and the judicious reasoning furnished in its support by Mr. Townsend; and we are inclined to consider it as the most probable of the geological speculations which have been maintained. But though we think our author has chosen his ground with discernment on the great scale, we can by no means assent to the manner in which he fills up particular positions. We cannot, for example, conceive how the other primitive rocks can be considered as the offspring of gra nite. Granite is stratified, and it is crystallized; therefore it was deposited from a chemical solution; and if the waters of the ocean held the materials of granite in solution, why may they not be supposed to have precipitated the other formations successively, as gneiss, mica-slate, &c. which recede gradually in their composition from the nature of granite. An inspection of the texture of these rocks, and the crystalline minerals which constantly accompany them, is sufficient to prove the fact.
We are not more disposed to agree with our author in his opinion of the origin of granular marble. He supposes it to have undergone igneous fusion, and to have lost the vestiges of organic bodies in consequence, and affirms it to be connected with volcanoes. But granular marble is a primitive rock, the beds of which are generally found subordinate to the mica-slate formation. Von Buch traced it in this formation through a great part of Norway: it is impossible to refer its origin to fusion, without involving the primitive formations which contain it, in the like predicament. Its situation, moreover, is such as to preclude the idea of its ever having contained organic bodies, or having been in any manner the product of volcanic operations.
But it is now time to add a few remarks on the proofs of the universal deluge. The foregoing view of the convulsions to which our globe has been subjected prepares us for the admission of this wonderful catastrophe. The geological theory adopted by Mr. Townsend is highly favourable to this part of the Scriptural history. If we can trace the actual operation of agents sufficiently
powerful to elevate the continent of South America, and other extensive regions from the depths of the ocean, it is no longer difficult to conceive that the waters may have covered the highest mountains, and that great tracts of habitable land may have been submerged. But absolute and distinct proofs of this event are to be found in the dislocations of strata, and in the phenomena connected with alluvial depositions.
There is no part of the earth in which the violent dislocations of the regular strata are not to be found, and they are chiefly abundant in mountainous tracts, of which no other proof need be cited than the vertical position which the strata forming high mountains now hold, while we are assured that these very strata were originally horizontal. But even in the most level countries we need not go far for evidences of these convulsions. Every river, every brook which breaks out under our feet, and every valley which diversifies the surface, owes its existence to the disruption of strata. All the rock formations were at first unbroken and continuous; wherever a valley occurs there is now an interruption of this continuity. That these hollows were not the mere effect of rivers which have worn out courses for their waters may be proved by a variety of geological facts which we have not room to introduce here; but it is put in a sufficiently strong light by Mr. Townsend's observations on springs, which are in a great measure new, and of very general interest. Every stratum of rock, before it becomes broken up, carries with it in its course under the surface a stratum of water, which percolates its stony beds, and is confined between impervious layers of clay. It is only where these subterranean courses are disturbed, and the strata are torn asunder by some extraneous force, that fountains and rivers burst forth. These dislocations and disturbances of strata can only be attributed to the agency of vast torrents every where flowing over and disorganizing the surface of the earth, and such torrents can only be furnished by the incursions of the Land floods and rivers are the effects of the previous disruption of the strata, and therefore cannot be considered the efficient causes.
That these phenomena were produced by the waters of the ocean is further proved by alluvial deposit. The vast extent of alluvions, independent of all other proof, declares that the ocean gave them birth. One great accumulation of debris fills nearly the whole of Flanders and Holland; it reaches across the Channel, and covers the southern and eastern counties of England, concealing under it, at a great depth, the regular strata of these districts. Another alluvion forms Lower Saxony and Holstein. Similar appearances occur in all level countries, and valleys are generally filled with these accumulations, through the midst of which the