Description of the Muschelkalk and Quadersandstein. By A. von Humboldt.

(Extracted from his Essai sur les Gisement des Roches, &c.)

Muschelkalk.

A formation which varies but slightly, and whose vague denomination of shelly limestone has caused it to be confounded out of Germany, with the lower or upper strata of the oolite formation (with the lias or forest marble).

It is well characterized by its more simple structure, by the prodigious quantity of shells, that are partly broken, which it contains, and by its position above the Nebra sandstone (new red sandstone), and beneath the quadersandstein which separates it from the oolite formation.

It covers a vast portion of northern Germany (Hanover, Heinberg near Gottingen, Eichfeld, Cobourg, Westphalia, Pyrmont, and Bielfeld), where it is much thicker than the zechstein or Alpine limestone (magnesian limestone).

It extends in southern Germany throughout the platform between Hanau and Stutgard.

In France, where, notwithstanding the labours of Omalius d'Halloy, the secondary formations beneath the chalk have been so long neglected, Messrs. de Beaumont and Boue have recognised it round the Vosges chain.

The muschelkalk generally possesses pale, whitish, grey or yellow tints: its fracture is compact and dull, but the mixture of small laminae of calcareous spar, arising perhaps from fossil remains, sometimes renders it granular and brilliant.

Many beds are marly, arenaceous, or passing into the oolite structure.

(Seeberg near Gotha; Weper near Gottingen; Preussisch-Minden; Hildesheim.

Chert (hornstein) passing into flint and jasper (Dransfeld, Kandern, Saarbrück), are either disseminated in nodules in the muschelkalk, or form beds of small continuity.

The inferior strata of this formation alternate with the new red sandstone (between Bennstedt and Kelme), or insensibly pass into the sandstone, by becoming charged with sand, clay, and even (to the E. of Cobourg) with magnesia (magnesian beds of the muschelkalk).

Subordinate beds.

The Marls and clays so frequent in the oolite formation, the new red sandstone, and the zechstein (magnesian limestone) are rare in the muschelkalk.

In Germany, this rock contains hydrate of iron, a little fibrous gypsum (Sulzbourg near Naumbourg), and coal (lettenkohle of Voigt; at Mattstedt and Eckardsberg near Weimar) mixed with aluminous schist and carbonized fruits (coniferae?).

The nearer coal is found to the tertiary formations, the more do at least some of its strata approach the state of lignite and aluminous earth.

Fossils.

From the researches of M. von Schlotheim, and rejecting the beds which do not belong to the muschelkalk, the fossils are:

Chamites striatus, Belemnites paxillosus, Ammonites amalteus, A. nodosus, A. angulatus, A. papyraceus, Nautilites binodatus, Buccinites gregarius, Trochilites laevis, Turbinites cerithius, Myacites ventricosus, Pectinites reticulatus, Ostracites spondyloides, Terebratulites fragilis, T. vulgaris, Gryphites cymbium, G. suillus, Mytulites socialis, Pentacrinites vulgaris, Encrinites liliiformis, &c. Some isolated beds of the oolite formation perhaps contain more fossils than the muschelkalk; but in no secondary formation do organic remains so uniformly abound as in that which now occupies us.

An immense quantity of shells, partly broken, and partly well preserved, but strongly adhering to the stone (entrochi, turbinites, strombites, mytulites) is accumulated in many strata from 20 to 25 millimetres (about 1 in.) thick, which occur in the muschelkalk.

Many species occur united in families (belemnites, terebratulites, chamites).

Between these very shelly strata are disseminated ammonites, turbinites, some terebratulites, with their nacreous shells, the Gryphaea cymbium, and superb pentacrinites.

Corals, echinites, and pectinites are rare.

From the abundance of entrochi in the muschelkalk, this formation has received the name of entrochite limestone (trochitenkalk) in some parts of Germany.

As a bed of entrochi often also characterizes the zechstein, and separates it from the coal measures, this name may lead us to confound two very distinct formations.

The denomination of gryphite limestone (calaire a gryphites of the zechstein and of the oolite formation) and all those which allude to fossils, without indicating the species, expose us to the same danger.

It is stated that the muschelkalk contains the bones of large animals (oviparous? quadrupeds, Friesleben, T. 1, p. 74; T. iv, p. 24, 305) and birds (ornitholithes of the Heimberg; Blumenbach, Naturgesch; 3te. Aufl. p. 663); but these bones may belong, as also the teeth of fish, to the breccias and marls resting on the muschelkalk.

Messrs. Buckland and Conybeare, during their tour in Germany, considered the muschelkalk of Werner as identical with the lias.

I am inclined to think that there is rather a parallelism than an identity of formation.

The muschelkalk occupies the same place as the lias, it equally abounds in ammonites, terebratulae, and encrinites; but the fossil species differ, and its structure is much more simple and uniform.

The muschelkalk strata are not separated by the blue clays which abound in the lias.

The middle strata of the latter possess a dull compact and even fracture, much more resembling the lithographic varieties of the oolite formation than the muschelkalk of Gottingen, Jena, and Eichsfeld. M.

Boue has recongnised the muschelkalk in France, in the platform of Burgundy, near Viteaux and Coussy-les-Forges, near Dax, in the commune of St.

Pan de Lon, &c. I have not observed this formation in the equinoxial part of America.

Quadersandstein (Sandstone of Königstein).

A very distinct formation (Banks of the Elbe, above Dresden, between Pirna, Schandau, and Königstein; between Nuremberg and Weissenburg; Staffelstein in Franconia; Heuscheune, Adersbach; Teufelsmauer at the foot of the Hartz; valley of the Moselle and near Luxembourg; Vic in Lorraine; Nalzen in the Pays de Foy, and Navarreins, at the foot of the Pyrenees) characterized by M. Hausmann, and for a long time confounded either with the quartzose varieties of the new red sandstone, the sandstone of the plastic clay, or with the sandstone of Fontainebleau, above the calcaire grossier of Paris: it is the white sandstone of M. de Bonnard, and the third formation sandstone of M. d'Aubuisson.

Preferring geographical names, I often call this formation the Königstein sandstone, the new red sandstone the Nebra sandstone, and the muschelkalk the Gottingen limestone.

The quadersandstein has a white, yellowish, or grey colour, with very fine grains, which are agglutinated together by a nearly invisible argillaceous or quartzose cement.

Mica is not abundant in it, and is always silvery and disseminated in isolated plates.

It neither contains the included oolite beds, nor the flattened lenticular masses of clay (thongallen) which characterise the new red sandstone.

It is never schistose; but is divided into very thick beds, which are cut at a right angle by fissures, and of which some easily decompose into a very fine sand.

It contains hydrate of iron (Metz)

disposed in nodules.

The organic remains disseminated in this formation present, according to Messrs. von Schlotheim, Haussmann, and Raumer, an extraordinary mixture of sea shells (very analogous to those of the muschelkalk) and dicotyledonous phytolithes.

In it have been found mytulites, tellinites, pectinites, turritellae, and ostreae, (with cerithia, but no ammonites; Habelschwerd, Alt-Lomnitz in Silesia), and at the same time the wood of palms, the impressions of leaves belonging to the class of the dicotyledons, and small deposites of coal (Deister, and Wefersleben near Quedlinbourg), very well described by Messrs. Rettberg and Schulze, and passing into lignite.

M. von Raumer had observed that the quadersandstein is separated from the new red sandstone by the muschelkalk; it is placed between this limestone and the Jura limestone, and consequently beneath the oolite formations of England and the continent.

In this position we cannot consider it, with M. Keferstein (see his Essay on the mineral geography of Germany, T. 1. p. 12. and 48.), as parallel to the molasse of Argovy (mergelsandstein), which represents the plastic clay beneath the chalk.

The nature of the vegetable remains contained in the quadersandstein, and its resemblance to the plänerkalk which belongs to the chloritous and sandy strata of the chalk, have caused it to be regarded by many celebrated geologists as a formation posterior to the oolite formation: thus Messrs. Buckland, Conybeare, and Phillips place it between the chalk and the upper beds of the oolites.

But, according to the observations of M.

Boue and many other celebrated German geologists, the quadersandstein, sometimes alternating with marly and conglomerate beds, rests immediately on gneiss near Freyberg, on the coal measures in Silesia, and in Bohemia; on the new red sandstone near Nuremberg in Franconia; on the muschelalk between Hildesheim and Dickholzen near Helmstädt, and near Schweinfurt on the Mein. It is covered by the oolite formation, and alternates with marly beds of this limestone in Westphalia, between Osnabrück, Bielfeld, and Bückebourg.