The banks of the Meuse at Maestricht, like those of the Rhine at Bonn and Cologne, are slightly elevated above the level of the alluvial plain. On the right bank of the Meuse, opposite Maestricht, the difference of level is so marked that a bridge with many arches has been constructed to keep up, during the flood season, a communication between the higher parts of the alluvial plain and the hills or bluffs which bound it. This plain is composed of modern loess, undistinguishable in mineral character from that of higher antiquity, before alluded to, and entirely without signs of successive deposition and devoid of terrestrial or fluviatile shells. It is extensively worked for brick-earth to the depth of about 8 feet. The bluffs before alluded to often consist of a terrace of gravel, from 30 to 40 feet in thickness, covered by an older loess, which is continuous as we ascend the valley to Liege. In the suburbs of that city patches of loess are seen at the height of 200 feet above the level of the Meuse. The table-land in that region, composed of Carboniferous and Devonian rocks, is about 450 feet high, and is not overspread with loess.
A terrace of gravel covered with loess has been mentioned as existing on the right bank of the Meuse at Maestricht. Answering to it another is also seen on the left bank below that city, and a promontory of it projecting into the alluvial plain of the Meuse and approaching to within a hundred yards of the river, was cut through during the excavation of a canal running from Maestricht to Hocht, between the years 1815 and 1823. This section occurs at the village of Smeermass, and is about 60 feet deep, the lower 40 feet consisting of stratified gravel and the upper of 20 feet of loess. The number of molars, tusks, and bones (probably parts of entire skeletons) of elephants obtained during these diggings, was extraordinary. Not a few of them are still preserved in the museums of Maestricht and Leyden, together with some horns of deer, bones of the ox-tribe and other mammalia, and a human lower jaw, with teeth. According to Professor Crahay, who published an account of it at the time, this jaw, which is now preserved at Leyden, was found at the depth of 19 feet from the surface, where the loess joins the underlying gravel, in a stratum of sandy loam resting on gravel and overlaid by some pebbly and sandy beds. The stratum is said to have been intact and undisturbed, but the human jaw was isolated, the nearest tusk of an elephant being six yards removed from it in horizontal distance.
Most of the other mammalian bones were found; like these human remains, in or near the gravel, but some of the tusks and teeth of elephants were met with much nearer the surface. I visited the site of these fossils in 1860 in company with M. van Binkhorst, and we found the description of the ground, published by the late Professor Crahay of Louvain, to be very correct.*
(* M. van Binkhorst has shown me the original manuscript
read to the Maestricht Athenaeum in 1823. The memoir was
published in 1836 in the "Bulletin de l'Academie Royale de
Belgique" volume 3 page 43.)
The projecting portion of the terrace, which was cut through in making the canal, is called the hill of Caberg, which is flat-topped, 60 feet high, and has a steep slope on both sides towards the alluvial plain. M. van Binkhorst (who is the author of some valuable works on the palaeontology of the Maestricht Chalk) has recently visited Leyden, and ascertained that the human fossil above mentioned is still entire in the museum of the University. Although we had no opportunity of verifying the authenticity of Professor Crahay's statements, we could see no reason for suspecting the human jaw to belong to a different geological period from that of the extinct elephant. If this were granted, it might have no claims to a higher antiquity than the human remains which Dr. Schmerling disentombed from the Belgian caverns; but the fact of their occurring in a Pleistocene alluvial deposit in the open plains, would be one of the first examples of such a phenomenon. The top of the hill of Caberg is not so high above the Meuse as is the terrace of St. Acheul with its flint implements above the Somme, but at St. Acheul no human bones have yet been detected.
In the museum at Maestricht are preserved a human frontal and a pelvic bone, stained of a dark peaty colour; the frontal very remarkable for its lowness and the prominence of the superciliary ridges, which resemble those of the Borreby skull, Figure 5. These remains may be the same as those alluded to by Professor Crahay in his memoir, where he says that in a black deposit in the suburbs of Hocht were found leaves, nuts, and freshwater shells in a very perfect state, and a human skull of a dark colour. They were of an age long posterior to that of the loess containing the bones of elephants and in which the human jaw now at Leyden is said to have been embedded.