76 
GEOLOGICAL REPORT—THIRTY-FIFTH PARALLEL. 
or five thousand feet, and separates it provisionally into three divisions : the first, or lower, cor¬ 
responding to the Bunter-sandstein , or Gres bigarres; the second, or middle, to the Muschelkalk; 
and the third, or upper, to the Keuper or Marnes irisees . 1 
Mr. Marcou’s conclusions upon the age of the formation, and the correspondence with the 
groups into which the European formation is divided, appear to rest almost entirely upon the 
mineral characters of the strata. The only distinct fossils found were silicified trunks of trees, 
one of which was thought to “ very much resemble the Pinites fleurotii of Dr. Mougeot.” As 
no specimen of this tree is in the collection, I have not had an opportunity to examine it ; hut 
even if it were proved to he identical with P . fleurotii , I cannot agree with Mr. Marcou in his 
1 For the convenience of the general reader, I append a short description of the Trias of Europe with its divisions, and of 
the Permian formation as developed in Russia. 
In England and France, we find between the strata of the coal formation and those of the Lias a great series of red sandstones 
and shales, to which the name New Red Sandstone was first given, in order to distinguish between it and simdar rocks which are 
found below the coal, and are known as the Old Red Sandstones. The name Poikilitic was afterwards proposed, this name having 
reference to the variegated colors of the strata. After the fossil remains of the series had been more fully investigated, it was 
found desirable to form two divisions, and these were called Upper New Red and Lower New Red. The first is now generally 
known as the Trias; while the second, or Lower New Red, is called Permian. 
The name Trias was adopted by German writers, because the Upper New Red Sandstone could be separated into three principal 
subdivisions, which were called the “Keuper” the “Muschelkalk,” and the “Bunter-sandstein.” The same subdivisions are 
known among French geologists as the “ Marnes irisees ,” the “ Calcaire coquillier,” and the “ Gris bigarrl.” These subdivisions, 
with their respective terms in German and French, are clearly shown in the annexed table, taken from Lyell’s Geology. 5 ’ 
SYNONYMS. 
Trias, or Upper New Red Sandstone. 
a. 
b. 
c. 
Saliferous and gypseus shales and sand¬ 
stones. 
(Wanting in England.) 
Sandstone and quartzose conglomerate. 
} 
} 
German. 
Keuper. 
Muschelkalk. 
Bunter-sandstein. 
French. 
Marnes irisees. 
Muschelkalk, ou cal¬ 
caire coquillier. 
Gres bigarre. 
In England, the upper division of the Trias consists chiefly of fine red clays and thinly bedded sandstones, interstratified with 
beds of gypsum, and containing rock-salt. This division has nearly the same characters in Germany, consisting of variegated 
marls, with gypsum and sandstone. Fossils have been found in it, such as teeth of placoid fish, and remains of reptiles, inclu¬ 
ding the Labyrinthodon. The fossil plants are generically analogous to those of the Lias and Oolite, and consist of ferns, equiseta- 
ceous plants, cycads, and conifers, with a few doubtful monocotyledons. In France, the Keuper , or Marnes irisees, have a very 
variable composition, and consist of beds of limestone, more or less clayey, and of strata of wine-colored clay, sometimes greenish 
and bluish. These strata and colors are much intermingled, and give the highly variegated color to the division—the character 
upon which its name is based. 
The great deposites of rock-salt of Cheshire county, England, are found in connexion with the gypsum and marls of the Keuper. 
The middle division of the Trias—the Muschelkalk, or Calcaire coquillier —is not found in England, but is developed in Germany 
and France, where it consists of a fossiliferous magnesian limestone, and beds of marl. The following description of this division 
as it occurs in France, is translated from Beudant :f “The Calcaire conchylieu commences by alternating at its base with the 
Gres bigarrl , while in its upper portions it passes into the Marnes irisles, which overlie it. The limestone is generally compact, 
greyish, green, or yellow. The upper portions are often magnesian, and frequently earthy. It gradually shades into the marls 
of the Marnes irisles, (Keuper,) among which some beds of limestone, either pure or magnesian, are again found. It often 
presents siliceous pebbles of considerable size, and contains a large quantity of shells.” 
The Bunter-sandstein, or Gris bigarrl, consists of sandstones, alternating with thin beds of dolomite and beds of clay. Ac¬ 
cording to Beudant, the sandstone is quartzose, fine-grained, and generally of a red color; portions of it are white, blue and 
green, which produces the mixture ( bigarrure ) of colors to which it owes its name. In England, this lower division of the 
Trias is found developed in Cheshire and Lancashire counties. It consists of red and green shales, and red sandstones, and con¬ 
tains much soft white quartzose sandstone, in which the trunks of silicified trees have been found. These were of coniferous 
wood, and showed rings of annual growth.$ Impressions of the feet of animals have also been found. 
The Trias, as developed in England and on the continent, is of variable thickness. In the salt region of Cheshire, the total 
thickness is said to be at least 1,100 feet.g The upper group of the Keuper attains a thickness of 100 feet. 
According to Messrs. Murchison and Strickland,|| this upper division is about 600 feet thick in Worcestershire and Warwick¬ 
shire. In At irtemburg, the Keuper is 1,000 feet thick.fT The Muschelkalk of the middle division is not found in England, but its 
° Elements, 5th edition, p. 335. 
f Beudant Geologic, p. 211. 
% Lyell, Elements of Geology, 5th edition, p. 339. 
§ Phillips, p. 266. 
|] Geol. Trans., second series, Vol. V, p. 318. 
T L yell, Elements of Geology, 5th edition, p. 335. 
