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Connected with the view which supposes the continuation of a paleozoic flora up to the epoch of the lias is a question raised by our author (p. 29) regarding the association (established by comparison of considerable lists of species from various localities), of the fossils of the different stages of the lias in a single bed. Analogous cases are frequently met with at different geological horizons, showing that the causes which have limited the vertical range of certain animals are so far local, that under somewhat modified conditions the duration of a species may be prolonged after its disappearance from the adjacent seas. As our author has well said, it is in the continuation of similar chemical and physical conditions, generally dependant upon local accidents of the surface, that we must look for the cause of these apparent anomalies in the distribution of fossils. The investigations of Prof. Safford in Tennessee and Sir William Logan in Canada have made known a remarkable example of this in the Lower Silurian series of North America. In the State of New York the fauna of the Black River and Trenton limestones are almost totally distinct, so that the division between the two formations constitutes a wellmarked paleontological horizon, while in Canada and in Tennessee the fossils of the two formations are so completely intermingled that it is impossible to distinguish between the Black River and Trenton limestones. (Billings, Report Geol. Survey of Canada, 1857, p. 152.) The genus Catenipora in North America also presents a remarkable instance of anomalous distribution; this coral throughout New York and Western Canada is Upper Silurian and is unknown below the Clinton Group, while at Lake St. John on the Saguenay it is abundant in the Black River limestone, a position which corresponds with its geological horizon in Europe.

The anthracitic system of the Alps has been described by Gras with great minuteness in the memoir cited above. He estimates the total thickness of the system at between 25,000 and 28,000 feet, and divides it into an upper and lower series, which are unconformable. The former with a thickness of about one-tenth of the whole, is referred to four subdivisions, and consists chiefly of argillo-calcareous shales terminated by a considerable mass of limestone, immediately beneath which occurs a bed of spilite, associated with gypsum and a yellow altered dolomite. The inferior division also consists in great part of similar shales, interstratified with gneissoid and talcose rocks to be noticed farther on; gypsum and a yellow altered limestone (dolomite?) also occur in this portion. In both the upper and lower divisions sandstones and shales are found with coal plants and layers of anthracite, the latter sometimes changed into graphite, while the associated calcareous shales contain in various localities, and at different horizons, belemnites and ammonites of liassic age.

Sismonda confirms the accuracy of the observations of Gras, and admits an upper anthracitic series, resting unconformably upon the lower, and of oolitic age, the lower only being referred by him to the lias proper, while Studer concludes the discussion of the subject as follows: "The intercalation of the lower anthracitic slates sometimes with gneissoid and talcose schists, and sometimes with the belemnitic shales, the layer of jurassic limestone which separates the lower from the upper anthracites, the extraordinary thickness of this calcareous layer and the anthracitic

zone which covers it, the presence of the verrucano (or talco-quartzose conglomerate) between these two formations and the quantity of talc disseminated in all these rocks, present us problems which science is not able to solve completely."-(Studer, cited by Laugel, Bull. Soc. Geol. de France, [2], xii, 576.)

In the metamorphic rocks of the anthracitic system Gras distinguishes what he calls a protogine or talcose formation, consisting of granite, gneiss and mica slates, generally more or less talcose, containing also schistose diorites, eurites and leptynites. This protogine formation is intimately associated with the argillo-calcareous shales of the lower anthracitic series, which are found interstratified with and even passing into gneiss and other feldspathic schists. Gras concludes that this somewhat irregular interpenetration of the two classes of rocks is due to an irregular metamorphism, portions of the argillo-calcareous sediments having, as he supposes, been profoundly altered by emanations from below, and he hence regards the protogine formation as a portion of the inferior anthracitic series. Similar crystalline schists also occur in some parts of the upper anthracitic series, and in both the upper and lower there are found serpentines, euphotides, porphyries and spilites, all of which the author regards as of sedimentary origin, and as having undergone in situ a profound metamorphism which has often effaced the marks of stratification; this view he declares is the only one which appears to agree with the observed facts. This protest against the theory of the igneous origin of serpentines is in accordance with the results obtained by the Geological Survey of Canada; in his report for 1848 Sir William Logan insisted upon the sedimentary origin of the serpentines which occur in the altered palæozoic strata of the Green Mountains.

Rozet, in his investigations of the Alps, has referred to the liassic and jurassic periods the great system of gneiss, with micaceous and talcose schists, which makes up Mts. Cenis and Pelvoux, and a great part of the mountains of the frontier of Piedmont, while, according to Fournet, the jurassic rocks of the Valais have been altered in like manner. (Coquand, des Roches, pp. 300–301.)

Our author however supposes that all these altered strata are of carboniferous age, and remarks that the fossils in the limestone of the lower lias show but slight marks of metamorphism, from whence he concludes that "in this region of the Alps there are no highly metamorphosed jurassic rocks," and that the metamorphic action "which took place beneath the sea before the elevation of these mountains" ceased to be powerful after the deposition of the Valorsine conglomerate, (which he regards as of carboniferous age,) the paste of which is often converted into a crystalline talcose schist. At the same, although the liassic and so-called triassic rocks are comparatively unaltered, the jurassic shales are described as more or less talcose and greasy to the touch, but the alterations of these argillaceous rocks our author regards as rather mechanical than chemical." (p. 76.)

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The question before us is then, whether in that series of rocks which embraces liassic and jurassic beds with gypsum, dolomite, anthracite, and a carboniferous flora, and which geologists have generally referred to one great system not older than the lias, we have really in these mountains,

as Favre supposes, the whole succession of formations from the oolite to the carboniferous inclusive, so involved by foldings and inversions that it has hitherto been impossible to determine their real structure.

But even if we admit with Favre the paleozoic age of the protogine formation described by Gras and Rozet, we cannot agree with him in limiting to the rocks of that period the action of the metamorphic process. The development of a talcose character in the jurassic shales we cannot regard as the result of a mechanical process, and we have besides evidences in the Alps of the metamorphism of still higher rocks.

As early as the year 1834 Keferstein had asserted that the granites of Mont Blanc are nothing more than altered strata of flysch, (Naturgeschichte des Erdkörpers, i, 286–292; Bul. Geol. Soc. de France, [1], vii, 198,) and in 1850 Sir Charles Lyell in his address before the Geological Society of London suggested that the protogines of the Alps might be of tertiary age. This is so far true that both Studer and Murchison have shown that portions of the eocene flysch have been converted into crystalline gneiss, mica slate and even granitic beds; Murchison, like Gras, whom we have already cited, remarks that the metamorphism seems irregular, some bands of the rock being apparently much more altered than others. (Geol. Journal, v, 164, 210.) The intercalation of wedgeshaped masses of fossiliferous limestone of liassic age among the gneissic strata of the Alps has been well described by Studer (Bul. Soc. Geol. de France, [2], iv, 208), and similar phenomena observed in various other metamorphic regions present a problem the right understanding of which is most important in its relations to the theory of metamorphism, and one which we propose to consider at an early day.

In conclusion we hasten to say, that although dissenting from some of the views of Mr. Favre, we are not less grateful for his very suggestive memoir, which with its carefully prepared lists of fossils and its beautiful sections is a valuable contribution to alpine geology.

T. STERRY HUNT.

2. The Geological Structure of the "Jornada del Muerto," New Mexico, being an abstract from the Geological Report of the Expedition under Capt. John Pope, U. S. Top. Eng., for boring Artesian Wells along the line of the 32d parallel; by G. G. SHUMARD, M.D., Geologist of the Expedition, (Trans. Acad. Sci. St. Louis, vol. i, No. 3, p. 341. 1859).-This paper gives a description of the geological structure of a district of country lying immediately east of the Rio Grande, and between the 32d and 34th parallels. The "Jornada del Muerto" is described as a gently sloping plane, of an elliptic form, from twelve to forty miles in breadth, and extending from near the southern extremity of the Doña Ana Mountains eighty or ninety miles in a N.N.W. direction. It is bounded on the east and west by ranges of mountains, varying in their elevation from two or three hundred to one thousand feet above the plane, and seem to be mainly composed of dark colored limestones of Upper Carboniferous age, dipping towards the interior of the intermediate plane; these rocks however, in the western range, were observed at some places, surmounted by shales and sandstones referred to the Cretaceous epoch. Igneous rocks form a belt of low hills along the eastern side of the eastern range, and also occur between the other and the Rio Grande. From the structure of

the surrounding country, the "Jornada" is supposed to be a great synclinal depression, in which water could probably be obtained by artesian borings, through heavy detrital deposits.

The fossils found in the Carboniferous rocks here, and in the Organ Mountains, are all Upper Carboniferous types, many of them being identical with species almost everywhere common in the western Coal Measures. Those mentioned in the Cretaceous beds are Inoceramus and Cardium. The paper also contains interesting local details in regard to the igneous and metamorphic rocks of the several mountain ranges explored.

M.

3. Notice of Fossils from the Permian strata of Texas and New Mexico, obtained by the United States Expedition under Capt. John Pope, for boring Artesian Wells along the 32d parallel, with descriptions of new Species from these strata and the Coal Measures of that region; by B. F. SHUMARD, M.D., (Trans. Acad. Sci. St. Louis, vol. i, Part 3d. 1859).— This is an important paper, containing descriptions of many new species, with an enumeration of others identified with forms known in the Kansas rocks, and of a few which are, by the author, supposed to be identical with foreign species; it is also illustrated by an excellent plate of twentyseven figures by Leopold Gast & Brother of St. Louis.

Most of these fossils are from an extensive deposit of white limestone, and inferior beds of sandstone and darker colored limestone, in the Guadalupe Mountains, referred by Dr. S. to the Permian System. The new species described from these rocks are

Campophyllum? Texanum, Chonetes Permiana, Spirifer Guadalupensis, Terebratula perinflata, Rhynchonella indentata, R. Texana, Camerophoria Swalloviana, Crania Permiana, Arinus securis, Turbo Guadalupensis, Pleurotomaria Halliana, and Chemnitzia Swalloviana. Those from the beds regarded as Carboniferous, are Turbo Texanus, Straparollus cornudanus, Pleurotomaria Proutiana, P. obtusipira, P. perornata and Machrocheilus Texanus.

All of which appear to be described with the author's well known care and accuracy.

Dr. S. had previously described from the beds he places in the Permian, Phillipsia perannulata, Fusulina elongata, Productus Mexicanus, P. pileolus, P. Popei, Strophalosia (Aulosteges) Guadalupensis, Spirifer Mexicanus, S. sulciferus, Spiriferina Billingsii, Terebratula perinflata, Rhynchonella Guadalupe, Camerophoria bisulcata, Retzia papilata, R. Meekiana, and Myalina recta,—

several of which are well illustrated in the plate accompanying the paper now under consideration. He also gives the following list of forms from these rocks, regarded by him, with more or less confidence, as identical with species occurring in the Permian and Upper Carboniferous beds of Kansas, viz:

Acanthocladia Americana, Productus Calhounianus, P. Norwoodii, Spirifer cameratus, Streptorhynchus (Orthisina) Shumardianus, Edmondia suborbiculata, and Pleuraphorus occidentalis; while he thinks he recognizes the following foreign species in the same association :-Chatetes Mackrothii, Productus semireticulatus, var. antiquatus, P. Leplayi?, Terebratula elongata, Camerophoria Schlotheimi?, Myalina squamosa, Monotis Speluncaria, and Turbo helicinus?.

As Dr. S. finds a Phillipsia and a Fusulina, in these rocks, neither of which genera are known to range up into Permian beds in the old world, and Spirifer cameratus is a characteristic Coal-measure species, from Pennsylvania to the Rocky Mountains; while Productus semireticulatus,

is regarded by most authors as peculiar to the Carboniferous systemand a large proportion of the other species mentioned as common to the New Mexican and Kansas rocks, are known to occur in the latter territory in beds containing even a majority of well marked Coal-measur♦ species, we may infer that in New Mexico, as in Kansas, there is a considerable blending of Carboniferous and Permian types; so that it becomes a matter of doubt and difficulty to determine at what particular horizon the line of demarkation should be drawn between these two Systems, if indeed there is any such natural break in our upper Palæozoic series of this country. It is to be hoped Dr. S. will continue his investigations of the fossils occurring in these formations, which he will doubtless have an opportunity to do, in connection with the geological survey of Texas, under his charge.

M.

4. Observations on the Geology of the County of Ste. Geneviève, being an extract from the Report made to the Missouri Geological Survey, in 1859; by B. F. SHUMARD, M.D., (Trans. St. Louis Acad. Sci., vol. i, part 3, page 404, 1859.)-In addition to information respecting the iron and lead mines, building materials, &c., of the county, this extract contains some facts having an important bearing on mooted points in the classification of the Lower Carboniferous Series of the West. Dr. S. found this series to be composed of the following members, in the descending order: 1st. THE UPPER ARCHIMEDES LIMESTONE, characterized by Pentremites pyriformis, P. sulcatus, Agassizocrinus dactyliformis, Spiriferina spinosa, Spirifer trigonalis, and species of Archimedipora. 2d. THE FERRUGINOUS SANDSTONE, in which no fossils were found,-estimated thickness, 80 to 100 feet. 3d. THE STE. GENEVIEVE LIMESTONE, a second Archimedes bed, in which the following fossils were found:-Rhynchonella trimela, R. Wortheni, Spirifera hirsuta, Retzia Marcyi, Spiriferina spinosa, Spirifera Leidyi, Productus elegans, P. bisulcatus, Murchisonia vermicula, Pentremites florealis, and one or more species of Archimedipora.

4th. THE SAINT LOUIS LIMESTONE-containing Lithostrotion mammillaria, Archæcidaris and Pentremites conoides,-thickness 100 feet or more.

5th. THE THIRD ARCHIMEDES LIMESTONE, containing Pentremites laterniformis, P. conoides, Archimedipora, Dichocrinus simplex, Spirigera hirsuta, Productus Indianensis, Rhynchonella subcuneata, and Holopea Prouti,-thickness from

100 to 150 feet.

6th. THE ENCRINITAL LIMESTONE (= BURLINGTON LIMESTONE), with its usual fossilsbeing the lowest member of the great Carboniferous series.

Of the Devonian rocks he recognizes the CHEMUNG GROUP, HAMILTON GROUP, and the ORISKANY SANDSTONE. Of the Silurian-1st. LOWER HELDERBERG SERIES, 2d. The NIAGARA GROUP, 3d. The HUDSON RIVER GROUP, 4th. The RECEPTACULITE LIMESTONE, 5th. The TRENTON LIMESTONE, 6th. The BLACKRIVER and BIRDSEYE LIMESTONES. Then comes the five members of the GREAT MAGNESIAN LIMESTONE SERIES, which represents the Calciferous, and possibly portions of the Potsdam and Chazy Limestones of New York; and last of all, eruptive rocks.

Of the Coal measures, only thin outliers cap the hills half a mile above St. Mary's on the Mississippi. The beds are alternations of shale and sandstone, surmounted by a thin bed of hard siliceous limestone.

M.

5. Third Series of Descriptions of Bryozoa, from the Paleozoic Rocks of the Western States and Territories; by H. A. PROUT, (Trans. Acad. Sci. St. Louis, vol. i, part 3, p. 443, 1859.)--Every geologist who has

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