ACCOUNT OF THE CAVE CONTAINING BONES AT ADELSBERG IN CARNIOLA.
The following interesting account of the cave, slightly noticed at pages [524 and 525], is extracted from a memoir by M. Bertrand Geslin, Member of the Natural History Society of Paris, published in the number of the Annales des Sciences Naturelles for April 1826.
M. Cuvier, says Gesler, speaking of the Adelsberg Cave, from the account published by M. Volpi of Trieste, says, that it was nearly two leagues from the entrance where he discovered bones of animals.
Having visited this cave myself, I am obliged to say that M. Volpi’s assertion as to this matter is not very correct. On my way to Trieste, in July 1823, before going to Adelsberg, I had the advantage of seeing M. Volpi. In shewing me the bones collected by him at Adelsberg, he also assured me that they were found two leagues from the entrance of the cave, and only in a very compact block of several cubic feet, from which it was not possible to procure more, as he had taken all that he could easily remove.
Notwithstanding this discouraging account, I betook myself to Adelsberg, in order to see a sample of those immense caverns of secondary limestone. The entrance of the cave is situated in a white compact secondary limestone, lying in great beds inclined to the south-west, at an angle of from 30 to 35 degrees. At fifty paces from the entrance, we find ourselves as in a large apartment, which crosses the torrent of the Pinka. After passing to the left bank of this torrent, we enter a rather low and not long passage, which leads to a second apartment of an elongated form. It is here that the line of chambers truly commences. They are of large but variable dimensions, and are situated nearly upon a horizontal plane.
On entering this second chamber, I saw that the ground was formed of a yellow and reddish clayey mud, from one to two feet thick, and more or less impregnated and covered with crusts of yellow stalagmites. In the places where it offered little resistance, I dug it up with the point of my hammer, and was fortunate enough to disunite some fragments of bone, although, from what had been said to me, I ought not to have expected to find them. From this I was convinced, that if M. Volpi had only found bones at a distance of two leagues from the entrance, it was because he had not been at the trouble to search for them nearer. I fell to work with more ardour, and succeeded in digging up some in good preservation, such as radii, cubiti, femora, humeri, fragments of jaws, calcarea, toes, vertebræ, &c., belonging to bears of different sizes, of the species termed Ursus spelæus. It would appear that the hyena tribe is rather rare here, for I only procured a single bone belonging to it. It was particularly in two small lateral chambers, near the narrow passage, that I obtained a great quantity of these bones, the clay there having been dug up by the guides, in order to make the floor of the great apartment even with it.
I continued to dig as I advanced, and everywhere found bones more or less broken and enveloped in the clayey mud. After proceeding for half an hour, I fell in with a mass, in an apartment of considerable dimensions, which was of a conical form, and composed of blocks of compact white limestone, of all sizes, mixed with yellowish clayey mud. These blocks had their edges as sharp as if they had only been lately broken. The mass, which reached to the right wall of the cave, might be fifteen feet in height, and twenty in diameter at its base: it was covered with stalactite in several places. It was in this mass, at about ten feet above the floor of the cave, in the clayey mud that filled up the interstices between the blocks, that I found the entire skeleton of a young bear, in a space of two square feet at most. The bones which I dug out were the frontal part of the head, the lower jaw of the left side, the seventh cervical and eighth dorsal vertebræ; the eighth and fourteenth ribs of the right side; two tibia, femora, and cubiti, and two large canine teeth of another bear. If I could have raised up the limestone blocks, between which these bones lay, I might without doubt have procured a great part of this skeleton. There are still found here and there in the cave some small heaps of clayey mud, with fragments of white secondary limestone, as well as large isolated limestone blocks, which the guides are daily destroying, to make the floor even for the convenience of visitors.
I had only advanced an hour and a quarter’s progress into the cave, always finding bones, when the oil of my lamps beginning to fail, I was obliged to return without reaching the block in which M. Volpi had found the first bones. This block is without doubt owing to the same causes as the heap of which I have spoken above.
The manner in which these heaps exist, being composed of blocks of compact white secondary limestone, similar to that which forms the walls of the cave, with sharp edges, and piled upon each other, made me imagine that they might have fallen from the roof. As I returned, I examined the ceiling of the vaults with attention. As it was all covered over with stalactites, I could not discover any fissure.
From this short excursion in the Adelsberg cave, I am induced to believe, that the bones exist along the whole extent of the cave, and that they occur in two different ways; 1st, scattered in the clayey mud which forms the floor of the chambers; and, 2dly, buried in heaps formed of blocks of white secondary compact limestone, and yellow clayey mud.
The hypothesis which M. Cuvier admits as the most probable for explaining the presence of these bones in the caves, is that which would make these caves to have served as a retreat to carnivorous animals.
The presence of bones in the clayey mud of the floor of the Adelsberg cave accords well with this hypothesis; but the case is different with those which I found in the heaps of limestone blocks and clayey mud. The bones are not at the surface of the heap, but rather towards its middle part, buried among the blocks, and crushed by them. From this position, and the height at which the skeleton mentioned above occurs from the floor of the cave, it cannot be supposed that it formed part of the bones with which the bottom of the cave is strewed, nor that the blocks had fallen upon it. The bones contained in the heap in question must have been brought into their present position at the same time, and by the same cause as the limestone blocks. They could not, therefore, have belonged to animals which inhabited these caves, and died there peaceably.
If it be remarked, that these blocks, which are sometimes very large, heaped up above one another, and mixed with clayey mud, have their angles perfectly fresh, and are of the same nature as the limestone of the walls of the cave, it cannot be admitted that they have been brought from a distance. This mode of arrangement could only have been produced by their falling from the roof of the cave.
The following facts also give support to this opinion. In the cave of Gaylenreuth, a fissure of the third grotto, was the means, in 1784, of disclosing a new one, fifteen feet long and four broad, where the greatest quantity of hyena or lion bones were found. The aperture was much too small for these animals to have passed through it.
In a cave discovered in 1824, in the district of Lanark in Upper Canada, Mr Bigsby observed, that the floor was covered with debris of brown granular limestone, similar to that of the walls, and that the bones especially formed a heap there. He thinks that the animal, whose bones have been found in this cave, was much too large to have got into it alive or entire.—Silliman’s Journal, June 1825, p. 354.
It must therefore be also admitted here, either that the bones could only have got into the cave in the same manner as the heaps of blocks found in the Adelsberg cave; that is to say, by falling from the roof, or that the apertures have been closed since the period at which the animals were buried.
If it be now considered, 1st, That the surface of the secondary limestone mountains of Carniola is covered with a layer of reddish clay; and, 2dly, That the clayey mud of the heap in the Adelsberg cave is mineralogically the same as that which forms the floor of the cave; may it not be supposed, that the same catastrophe which produced the heaps in the cave may have, at the same time, introduced into it the reddish clayey mud of the surface, which, by extending itself over the floor of the cave, would have contributed to cover the bones that were lying there?
Moreover, may it not have been the case, that, after the caves had been inhabited by the carnivorous animals, the substances falling from above, and coming from the surface of the soil, may have carried along with the clayey mud and the bones of bears, the spoils of large herbivorous animals, which they may have met with, and which cannot be supposed to have sought refuge in these caves during life.
There will, no doubt, be objected to me, that opinion which maintains, that the bones of herbivora have been dragged into the caves by the carnivorous animals. This might certainly have been the case with regard to small species, but it is not probable that the bones of large species could have been introduced in the same manner.
Admitting as certain, at least with regard to the Adelsberg cave, that the limestone blocks and the bear bones which accompany them, have fallen from the ceiling, the phenomenon of caves containing bones would connect itself pretty well with that of osseous brecciæ in a geological point of view. As M. Cuvier observes, “The nature of the rocks which contains the one and the other is not very different; and, besides, the fissures of caves being generally pretty wide, the bones would not have stuck, but would have fallen to the bottom, while those of the osseous brecciæ being much narrower, and not so deep, would have retained the bones at no great distance from the surface of the soil.”
Thus, from the facts observed in the caves of Germany and England, and from that of the Adelsberg cave, which I have described above, we may conclude, 1st, That the presence of bones in caves has been produced at two different periods, which, without doubt, have not been very distant from each other; the first, that when the animals inhabited these caves; the other, that when they had been transported there by a somewhat general catastrophe; 2dly, That the second epoch was contemporaneous with the osseous brecciæ, and was produced, like them, by a phenomenon or process of filling up.