GYPSUM FORMATION, ITS PROBABLE AGE. 
77 
statement “that it establishes a connexion between the New Red of France and that of 
America.” 
The collection contains a specimen from Cam^ 47, labelled “ Upper Trias,” which is a silicified 
fragment of the trunk of a Lepidodendron. 
Great value appears to have been placed in the indications of age presented by the deposite of 
gypsum—this mineral being considered characteristic of the New Red or Triassic formations. 
The divisions of the formation are so arranged by Mr. Marcou that the gypsum deposites are 
included in the middle group. He regards them as establishing a connexion with the gypseous 
strata of Nova Scotia, at Windsor and Plaister Cove, and at Prince Edward Island, also with 
the strata of New Jersey. 1 These deposites at Windsor and Plaister Cove have been shown by 
Mr. Dawson 2 to he in the carboniferous formation, where they are closely associated with the 
characteristic fossils of that period, such as Productus Lyelli, Terebratula elongata, Fenestella 
membranacea, Spiriferi, Orthoceras, and Connularia. 
Gypsum is found in the carboniferous formation, not only in Nova Scotia, hut in Iowa and 
in Virginia. In Iowa it occurs along the hank of the Des Moines in beds twenty-five feet thick, 
resting on pink shales. 3 It also occurs in large quantities in other formations in different parts 
of the world, and it is by no means characteristic of the New Red sandstone or Trias alone. 
equivalent, consisting of laminated sandstone, called water-stone, is 400 feet thick in Cheshire. The English representative of 
the “Bunter,” or lower division, reaches a thickness of over 600 feet in the same locality, and in the Hartz mountains is over 
1,000 feet thick. The total thickness of the Trias, as developed in England and on the continent, may be considered as nearly 
2,000 feet. 
The characteristics of the lower or second great division of the New Red Sandstone, called Permian, or magnesian limestone 
also claims our attention in this place. 
Permian. —The careful study of the rocks of the New Red Sandstone developed the fact, that the lower portion of the group 
contained fossils, which were connected in a measure with those of the carboniferous era, and which were entirely different from 
those of the Trias. This fact was first brought prominently forward by Sir Roderick Murchison and his associates, who proposed 
for the division the name Permian ,® “ derived from the ancient kingdom of Permia, Russia, within and around which the neces¬ 
sary evidences have been obtained.”f The formations to which this name has been given attain an enormous development in 
Russia. According to the authorities just cited, the “ deposites repose upon carboniferous strata throughout more than two-thirds, 
of a basin, which has a circumference of not less than 4,000 English miles.”t These deposites are of very varied mineral aspect, 
and consist of grits, sandstones, marls, conglomerates, and limestone, sometimes enclosing great masses of gypsum and rock-salt. 
They are also much impregnated with copper, and occasionally with sulphur.? The general characters of the strata have also 
been summed up by Sir R. Murchison, in his recent work, Siluria. This description, coming from such distinguished authority, 
and from one who has so ably investigated the formation, I cannot but quote in full: 
“ Occupying the enormous area before mentioned, the Permian deposites of Russia are flanked and underlaid on the west, east, 
and north by upper members of the carboniferous rocks, but with little or no coal. These Permian strata of Russia seldom 
exhibit a mineral succession similar to that of rocks of the same age in Western Europe; and in different tracts of the vast region 
explored, they exhibit, as explained in the preceding quotation, many variations in their contents and relations. In some places, 
as on the river Kama, near the Volga, cupriferous red grits, with plants, underlie the chief limestones, to which succeed marls; 
but along the eastern limits of the system, as flanked by the Ural mountains, gypseous limestones form the base, followed by the 
red copper grits, sands, marls, and pebble beds, which extend on all side3 around the city of Perm. On the whole, indeed, 
whether we appealed to the sections on the banks of the great Dwina, above Archangel, or to the western flank of the Ural 
mountains, or to the banks of the Lower Volga, near Kazan, localities removed from each other by vast distances, we found that 
limestones, often interstratified with much gypsum, prevailed towards the base of the Russian deposites.”|| 
1 Mr. Marcou also connects this formation, or its lowest group, with the “ red sandstone that forms more than half tho 
contour of Lake Superior.” (See Resum A) It is hardly necessary to state that Messrs. Foster and Whitney, D. D. Owen, 
and Sir Win. Logan and his corps, have severally examined this sandstone with care, and consider it to be the equivalent 
of the Potsdam sandstone of New York. Its Triassic age is not admitted. 
2 Acadian Geology, p. 219. 
3 Report of a Geological Survey of Iowa, Wisconsin, and Minnesota, by Dr. D. D. Owen : Philadelphia, 1852 ; p. 126. 
° We are indebted for this elegant and comprehensive name to Sir R. Murchison, with whom it originated in 1841, as appears 
by the following note, taken from the foot of page 291 of Siluria: “The term was first proposed in a letter addressed by myself, 
at Moscow, to the venerable and accomplished Russian palaeontologist, Dr. Fischer, October, 1841. See Brown and Leonhardt 
Journal, an. 1841, and Phil. Mag., Vol. XIX, p. 417. 
tRussia and the Ural Mountains: Murchison De Verneuil and Von Kcyserling, Vol. I, p. 138. 
t Ibid., Vol. 1, p. 220. 
? Russia and the Ural Mountains, Vol. I, p. 138. 
|| Siluria, pp. 294, 295. 
