The resemblance pointed out by M. Prevost,* of the specimens of recent breccia from New Holland, in the museum at the Jardin du Roi, to those of St. Hospice near Nice, is confirmed by the detail given by Mr. Allan in his sketch of the geology of that neighbourhood;** in which the perfect preservation of the shells, and their near approach to those of the adjoining sea at the present day, are particularly mentioned; and it is inferred that the date of the deposit which affords them, is anterior to that of the conglomerate containing the bones of extinct quadrupeds, likewise found in that country. M. Brongniart also, who examined the place himself, mentions the recent accumulation which occurs at St. Hospice, about sixty feet above the present level of the sea, as containing marine shells in a scarcely fossil state (a peine fossiles) and he describes the mass in which they occur, as belonging to a formation still more recent than the upper marine beds of the environs of Paris.***
(*Footnote. Prevost manuscripts. See hereafter.)
(**Footnote. Transactions of the Royal Society of Edinburgh volume 8 1818 page 427 etc. See also the previous publications of M. Risso Journal des Mines tome 34 etc.)
(***Footnote. Brongniart in Cuvier Ossemens Fossiles; 2nd Edit. volume 2 page 427.)
The geological period indicated by these facts, being probably more recent than the tertiary beds containing nummulites, and generally than the Paris and London strata, accords with the date which has hitherto been assigned to the crag beds of Suffolk, Essex, and Norfolk:* but later observations render doubtful the opinion generally received respecting the age of these remarkable deposits, and a full and satisfactory account of them is still a desideratum in the geology of England. When, also, our imperfect acquaintance with the travertino of Italy, and other very modern limestones containing freshwater shells, is considered,** the continual deposition of which, at the present time, cannot be questioned (though probably the greater part of the masses which consist of them may belong to an era preceding the actual condition of the earth's surface) it would seem that the whole subject of these newer calcareous formations requires elucidation: and, if the inferences connected with them do not throw considerable doubt upon some opinions at present generally received, they show, at least, that a great deal more is to be learned respecting the operations and products of the most recent geological epochs, than is commonly supposed.
(*Footnote. Conybeare and Phillips Outlines etc. page 11, Geological Transactions 1 page 327 etc. Taylor in Geological Transactions 2nd series Volume 2 page 371. Mr. Taylor states the important fact that the remains of unknown animals are buried together with the shells in the crag of Suffolk; but does not mention the nature of these remains. Since these pages have been at the press, Mr. Warburton, by whom the coast of Essex and Norfolk has been examined with great accuracy, has informed me that the fossil bones of the crag are the same with those of the diluvial gravel, including the remains of the elephant, rhinoceros, stag, etc.)
(**Footnote. Some valuable observations on the formation of recent limestone, in beds of shelly marl at the bottom of lakes in Scotland, have been read before the Geological Society by Mr. Lyell, and will appear in the volume of the Transactions now in the press. See Annals of Philosophy 1825 page 310.)
Since it appears that the accretion of calcareous matter is continually going on at the present time, and has probably taken place at all times, the stone thus formed, independent of the organized bodies which it envelopes, will afford no criterion of its date, nor give any very certain clue to the revolutions which have subsequently acted upon it. But as MARINE shells are found in the cemented masses, at heights above the sea, to which no ordinary natural operations could have conveyed them, the elevation of these shells to their actual place (if not that of the rock in which they are agglutinated) must be referred to some other agency: while the perfect preservation of the shells, their great quantity, and the abundance of the same species in the same places, make it more probable that they lay originally in the situations where we now find them, than that they have been transported from any considerable distances, or elevated by any very turbulent operation. Captain de Freycinet, indeed, mentions that patellae, worn by attrition, and other recent shells, have been found on the west coast of New Holland, on the top of a wall of rocks an hundred feet above the sea, evidently brought up by the surge during violent storms;* but such shells are found in the breccia of Sicily, and in several other places, at heights too great, and their preservation is too perfect, to admit of this mode of conveyance; and to account for their existence in such situations, recourse must be had to more powerful means of transport.
(* Freycinet page 187. The presence of shells in such situations may often be ascribed to the birds, which feed on their inhabitants. At Madeira, where recent shells are found near the coast at a considerable height above the sea, the Gulls have been seen carrying up the living patellae, just taken from the rocks.)
The occurrence of corals, and marine shells of recent appearance, at considerable heights above the sea, on the coasts of New Holland, Timor, and several other islands of the south, was justly considered by M. Peron as demonstrating the former abode of the sea above the land; and very naturally suggested an inquiry, as to the nature of the revolutions to which this change of situation is to be ascribed.* From similar appearances at Pulo Nias, one of the islands off the western coast of Sumatra, Dr. Jack also was led to infer, that the surface of that island must at one time have been the bed of the ocean; and after stating, that by whatever means it obtained its present elevation, the transition must have been effected with little violence or disturbance to the marine productions at the surface,** he concludes, that the phenomena are in favour of a HEAVING UP OF THE LAND, BY A FORCE FROM BENEATH. The probable nature of this force is indicated most distinctly, if not demonstrated, by the phenomena which attended the memorable earthquake of Chili, in November, 1820,*** which was felt throughout a space of fifteen hundred miles from north to south. For it is stated upon the clearest evidence, that after formidable shocks of earthquake, repeated with little interruption during the whole night of the 19th of November (and the shocks were continued afterwards, at intervals, for several months) IT APPEARED, on the morning of the 20th, THAT THE WHOLE LINE OF COAST FROM NORTH TO SOUTH, TO A DISTANCE OF ABOUT ONE HUNDRED MILES, HAD BEEN RAISED ABOVE ITS FORMER LEVEL. The alteration of level at Valparaiso was about three feet; and some rocks were thus newly exposed, on which the fishermen collected the scallop-shell fish, which was not known to exist there before the earthquake. At Quintero the elevation was about four feet. "When I went," the narrator adds, "to examine the coast, although it was high-water, I found the ancient bed of the sea laid bare, and dry, with beds of oysters, mussels, and other shells adhering to the rocks on which they grew, the fish being all dead, and exhaling most offensive effluvia. And I found good reason to believe that the coast had been raised by earthquakes at former periods in a similar manner; several ancient lines of beach, consisting OF SHINGLE MIXED WITH SHELLS, extending, in a parallel direction to the shore, to the height of fifty feet above the sea." Such an accumulation of geological evidence, from different quarters and distinct classes of phenomena, concurs to demonstrate the existence of most powerful expansive forces within the earth, and to testify their agency in producing the actual condition of its surface, that the phenomena just now described are nothing more than what was to be expected from previous induction. These facts, however, not only place beyond dispute the existence of such forces, but show that, even in detail, their effects accord most satisfactorily with the predictions of theory. It is not, therefore, at all unreasonable to conceive, that, in other situations, phenomena of the same character have been produced by the same cause, though we may not at present be enabled to trace its connexion with the existing appearances so distinctly; and though the facts, when they occurred, may have been unnoticed, or may have taken place at periods beyond the reach of historical record, or even beyond the possibility of human testimony.