« AnteriorContinuar »
from each other in the depositories from which they were drawn? If thrown up successively from separate repositories, would they naturally be deposited from the waters of the ocean in separate layers? If introduced into the ocean in that manner, would the slight intermixture of them naturally take place, that is now seen in the strata? What is the third fact which gives confirmation to this view? Show how, if injected into the waters of the sea in the manner we have supposed, they would be diffused over wide areas. What may be presumed to have been their form when ejected into the ocean? Did their union in granules and larger bodies take place then probably or at a later period?
What explanations of important phenomena are furnished by these views that corroborate their truth? Could such elevations and depressions of the rocky surface of the earth as exist, have taken place, had the globe been as many geologists hold it once was, in a state of fusion? State the reason. How is it that heat and expansive gases are generated? Is all the latent heat evolved in matter that is in a state of perfect fusion? Were the interior of the globe in a state of fusion, would it necessarily be in a state of repose, so far as the generation of gases is concerned? Would volcanoes, be impossible in such a globe? Is this consideration overlooked by the geologists, who hold that the earth is now a molten ocean, except a thin rocky crust which forms its surface? Are the phenomena of earthquakes, volcanoes, and the elevation and dislocation of the surface, explicable on the views we have advanced? Show how these great processes may have been produced. Does this view of the causes of these great movements allow of their repetition as often as the strata indicate that they have taken place? Show how.
Do these views suggest an explanation of the great accumulation of vegetable matter in the localities where coal exists? Is it apparent that the materials generally, of which coal beds are formed, did not grow in the places where the coal lies? What is the proof of that fact? Is it clear also that the whole materials of a bed, must have been deposited at once, not slowly accumulated? What is the proof of that fact? Can they have been borne to the places where they were buried, by rivers? Why not? What then is the only force that could have swept them together? State in what manner it might happen. How does it appear that the materials of the coal beds were deposited in a short space? How does it appear that the strata which lie next above the coal, were immediately formed over them? What indicates that the strata in which the relics of animals are buried, were deposited with rapidity? What is the testimony of Mr. Daubney respecting it? Would the larger animals have decayed if they had not been immediately involved in the earthy and mineral matter in which their remains are preserved? Does the condition also of shells indicate that they were buried suddenly in the beds of mud which were their birth-place and residence; not swept from them by violent currents and long exposed to erosion and fractures before being interred in the strata in which they are now found? What is the testimony of Sir T. H. De La Beche respecting it? Do all these facts confirm the view we have advanced, by showing that the strata were formed with rapidity?
The Materials of the Strata derived from the Interior of the Earth.
This view of the mode in which the materials of the strata were introduced into the oceans and seas, suggests the probable reason that those animals that were invested with a covering of silex or lime, swarmed at periods in certain localities, in infinite numbers. The infusion into the waters of the ocean at those points, of the elements of which their shells are formed, perhaps at a temperature equal to or above that of the equatorial seas, and that rendered their propagation practicable through the whole year, may have been the cause of their extraordinary multiplication. The slight animalcula whose silicious sheaths are in a few places accumulated in vast masses, cast their coverings periodically, and, like other creatures of that order, multiplied with a rapidity in an inverse ratio to their minuteness. The bulk of their relics is not greater, perhaps, in proportion to their power of increase, than that of some larger animals. There is, at least, no satisfactory explanation of their infinite multitude on any other theory. The supposition of vast ages during which they existed, is altogether inadmissible; for they are not common to all geological times, but confined to periods of comparatively slight length; and there are no indications that the strata formed contemporaneously with them, occupied a long round of ages. Myriads as innumerable as those of the infusoria that sometimes now animate every drop of the ocean through hundreds of cubic miles, casting their sheaths at slight intervals, would in a few years accumulate masses as great as those imbedded in the strata.
It suggests a more probable solution than any other of the origin of rock salt, and the saliferous marls from which salt springs arise. Those marls were undoubtedly ejected, like all others, from the interior of the earth; and why should not the salt with which they are saturated have been ejected along with them? We know that soda exists in the depths of the earth, as it is a conspicuous element in many of the volcanic rocks; and chloride also, as it is an element of muriatic acid, which is one of the most common and abundant of the gases emitted from volcanoes.
"Muriatic acid seems to be generated during almost all the phases of volcanic action; for although some have attempted to establish a class of volcanoes to which the production of muriatic acid was peculiar, yet it would appear that there were none from which this gas is not in greater or less quantity disengaged."—Daubney's Description of Volcanoes, p. 60 1.
Their ejection in combination, and in such conditions as to form rock salt, however it may transcend our comprehension, is no more incredible than many other processes, of the occurrence of which we have ample evidence. There is no other theory of its origin that is not perplexed with insuperable objections.
This view of the rapidity with which the strata were formed, is confirmed by the softness and pliancy which they appear universally to have retained, till the time of their upheaval. That they were so soft when elevated as to be susceptible of flexion without breaking, is seen from the curvatures and contortions to which those of every species, especially from gneiss up to the last of the shales, sandstones, limestones, and coal beds of the carboniferous system, have been subjected.
"Contorted strata are common on the skirts or flanks of many mountain chains, appearing to show that before the latter attained their existing forms, there was a pressure from the central parts outward, causing the lateral contortions.
"To produce this effect—as in the Alps, between Rigi and the Hospice of St. Gothard—we seem compelled to suppose the wholo mass of the calcareous Alps—a series of mixed strata of limestone, argillaceous slates, shales, and sandstone, the former predominating—to have been in a yielding or comparatively soft state. We can scarcely suppose with any approach to probability, that the soft, yielding condition of this mass should have continued sufficiently