|SECOND GEOLOGICAL SURVEY OF PENNSYLVANIA - REPORT OF PROGRESS
P. DESCRIPTION OF THE COAL FLORA OF PENNSYLVANIA
AND OF THE
CARBONIFEROUS FORMATION THROUGHOUT THE UNITED STATES
BY LEO LESQUEREUX; ©1879
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©George Langford III, 2011
|Stratigraphical distribution of the coal plants.
49. The marine plants cannot be taken here into consideration, as they
cannot offer any positive indication in regard to the horizon of the
strata where they are found, and, indeed, are not likely to afford in
future time documents of importance on the subject. This, not merely on
account of the vagueness of their characters or the difficulty of their
determination, but because their types are preserved for a vast period
of time. Species of marine Algae apparently identical are observed from
the Devonian to the Cretaceous.|
I do not take any account of the species mentioned from the Devonian and the Catskill group. They are considered in the remarks on the succession and development of vegetable types.
§ 50. To the column of the Pocono are referred the plants partly described by Prof. Fontaine from the New River group, with those obtained by Prof. Meek from the Lewis tunnel, of Allegheny county, Virginia; a few from Pottsville, Mauch Chunk, Pittston, and those from the Sideling Hill tunnel in Huntingdon county, Pennsylvania.
The number is small. Excepting those of the New River group and of Lewis Tunnel, we have only from this geological division Sphenopteris flaccida, Archaeopteris obliqua, Archaeopteris obtusa, Archaeopteris minor, Archaeopteris Halliana, Archaeopteris hybernica, Archaeopteris Rogersi, Rhacophyllum truncatum, Lepidodendron corrugatum. Of these we may consider the Archaeopteris as Devonian or Catskill types, for Archaeopteris minor was obtained in numerous specimens from the Catskill red shale of Tioga county, Penn'a, by Mr. Sherwood, and Archaeopteris obtusa is from the same formation at Montrose; Penn'a; Sphenopteris flaccida is a type of the Old Red of Europe. Rhacophyllum truncatum is comparable to Cyclopteris Brownii, which, with Lepidodendron corrugatum, is Devonian in Canada. None of these species are found either identical or by analogous form in the Sub-conglomerate, except Archaeopteris Halliana and Lepidodendron corrugatum.
Taking separately the plants of the New River formation which Prof. Fontaine considers as partly devonian, continued into the Pocono*
Of these plants Alethopteris Helene is the more common species of the Sub-conglomerate of Alabama, also abundant in Arkansas and in the shale of the Jackson coal of Ohio. Megalopteris Dawsoni is apparently a narrow leaved form of Megalopteris Hartii, described by Prof. Andrews from the upper Waverly group of Ohio. Sphenopteris obtusiloba or Sphenopteris acuta is a sub-conglomerate and carboniferous species. These, with Sphenophyllum antiquum and Archaeopteris Halliana, completing the list of the plants of the New River group are all named in the list given here below of the plants from the Conglomerate of West Virginia.
Prof. Fontaine refers also to the New River formation the few plants described by Prof. Meek from the Lewis Tunnel; Pseudopecopteris Virginiana, a species closely allied to, perhaps a mere variety of Pseudopecopteris speciosa of the Sub-conglomerate of Alabama. Triphyllopteris Lescuriana, a beautiful form intermediate between Archaeopteris Bockschiana, sub-conglomerate in Pennsylvania, and Eremopteris, a genus of which all the species are sub-conglomerate or carboniferous, Lepidodendron Scobinfforme, described as Stigmaria minuta from the upper Red shale below Pottsville or from near the base of XII. Then Archaeopteris Alleghanensis which identified with Archaeopteris Roemeri is a lower or Pocono type.**
We have now for comparison the plants of the Conglomerate Series of West Virginia quoted and partly described by Prof. Fontaine, as follow:
Sphenopteris Haeninghausii , Calamites Roemeri, ? Lepidodendron, selaginoides, Sphenopteris adiantoides and Sphenopteris macilenta, Bornia radiata, Odontopteris gracillima, Callipteridium rugosum, Cordaites Robbii, ? Alethopteris Helenae, Calamites Cannaeformis, Alethopteris grandifolia, Neuropteris Smithsii, Neuropteris tenuifolia, two species of undescribed Sphenopteris; Sphenopteris spinosa, an Equisetitites, Asterophyllites acicularis, Trigonocarpus trilocularis, Megalopteris Hartii and another species provisionally named Megalopteris Swelleni, Sphenopteris obtusiloba, Archaeopteris Halliana, Sphenophyllum, antiquum, Odontopteris Newberrii, and Calamites approximates.
This list is a good abridged synopsis of the flora of the Sub-conglomerate, all the species except Archeopteris Halliana being true sub-conglomerate or lower carboniferous; for Sphenophyllum antiquum Daws. is an uncertain species described by the author from a single lobe, and determined also by Prof. Fontaine from a mere fragment of a lobe, and Asterophyllites accicularis is referable to Calamites ramifer, a sub or intra-conglomerate species, whose leaves are similar to those of Asterophyllites foliosus to which Schimper compares Asterophyllites accicularis. Calamites Roemeri and Cordaites Robbii are quoted by Prof. Fontaine as doubtful.
As remarked already, all the species of New River are mentioned in the above list, and though the species are few, as none of them have the characters of an inferior group or any devonian type, it is scarcely possible to admit the New River formation as older than the Sub-conglomerate, whose flora is distinctly characterized.
§ 51. This sub-conglomerate flora is represented by one hundred and five species, of which forty-five exclusively pertain to it. It has none of the older types, except those quoted from New River; among them Archaeopteris Halliana, which pass up to the Upper Waverly Sandstone of Ohio.
Of species continued upwards to more recent strata, it has nine in the Intra-conglomerate, twenty-two in the lower division of the true carboniferous coal A, B, C, and eighteen passing still higher to coal E, besides eighteen which represented in the whole thickness of the coal measures, are common species, and may be eliminated from any comparison made on the stratigraphical distribution. As seen upon the table where they are indicated by an horizontal line, none of them appear lower than the Sub-conglomerate. It is therefore from this well determined geological division that the more important and more numerous typical forms of the vegetation of the Carboniferous have had their origin.*
Stratigraphical determination places into this Sub-conglomerate a peculiar bed of shale discovered in the upper part of the Waverly Sandstone of Ohio, near Rushville, by Prof. E. B. Andrews. This shale has furnished, especially Megalopteris species and some others, described and figured by Prof. Andrews, which have not been found in any part of the productive Coal-measures.
The same formation also barren of coal has been observed near Port Bryon, Ill., as recognized by plants which are of the same type. At this last locality the horizon of the shale could not be positively ascertained, it was merely indicated as in the lowest strata of the Carboniferous of that country.
The originality of the characters of these plants, their dissimilarity from the type?of the other carboniferous species, either American 'or European, may be explained in supposing that there was already at the coal epoch a land flora distinct in its characters from that of the swamps forming coal, as is now the flora of the peat bogs, and that its remains being rarely preserved are still mostly unknown to us. Except two species of Megalopteris found in Canada and W. Virginia and Archaeopteris Halliana, all the species of this isolated formation are peculiar and limited to it. They are indicated upon the fourth column by letter M.
§ 52. The intra-conglomerate plants are marked upon two divisions of the fourth column, the left side for those of the bituminous coal measures, the other for the anthracite.
The whole group has one hundred and sixty-seven species, thirty of which are peculiar to it. Twenty-nine of these are found in both the anthracite and the bituminous, four of them limited to the group; thirteen are also in the Sub-conglomerate, especially in that of W. Virginia, and twenty-five pass above, especially to the lower strata, A to C, of the true Carboniferous.
This group is remarkable for its abundant remains of fructifications found mostly at Cuyahoga Falls, Ohio, and under the Campbell's ledge of Pittston. At Cuyahoga Falls the seeds are associated with Ferns, especially Alethopteris grandifolia, Lepidodendron Veltheimianum, three species of Sigillaria and Whittleseya elegans, while under the Campbell's ledge of Pittston, they are found with few Ferns, Calamites ramifer, two species of Spirangium, Lepidodendron Veltheimianum and two species of Cordaites. Some of these numerous seeds are hypothetically referred to Whittleseya and to Cordaites; others to Lycopodiaceae.
The Coal beds of Youngstown are identified with those of Cuyahoga Falls by the presence in both of some identical species, by the abundance of seeds and by the affinity of types. But until now I have not obtained sufficient materials in plant remains from the Coal beds of Sharon to know if they are referable by their vegetation to the intraconglomerate or the sub-conglomerate measures.
Most of the specimens seen from around Sharon represent Lepidodendron and Sigillaria species, with few fruits. These remains agree in characters with those of the upper coal of Tennessee, the Sewanee mine, which, with Alethopteris Serlii, Alethopteris lonchitica and Asterophyllites grandis, has five species of Sigillaria and five of Lepidodcndron.
The Aetna vein of Tennessee, however, with Sphenopteris tridactylites, Sphenopteris Hildreti, Sphenopteris furcata, three species of Lepidodendron and three of Trigonocarpus has its place in the Sub-conglomerate. Therefore, the upper coal of Tennessee, like that of Sharon, may be intermediate to one of the members of the Conglomerate, XII.
§ 53: It is from the lower coal beds of the true Carboniferous, or from Coal A, the first above the Conglomerate, that we have the more numerous and more important data.
Sometimes two, even the three of the lower coal beds of the Productive Carboniferous, A, B, C, of Lesley's manual are close to each other, even united in one, and for this reason have been indicated in the Reports of the Geol. Survey of Kentucky, by D. D. Owen, as la, lb, lc. For in Kentucky, Coal lc is either the third bed above the Conglomerate, or the second, even the first, by connection with one or the two lower. It is generally a cannel coal, or pass at short distances from cannel to bituminous, in such a way that sometimes cannel coal is taken out at one side of a mine, and bituminous coal at the other.
It is now questionable if the lower coal strata of Illinois seen at Mazon Creek, Morris, Murphysborough, and Colchester, can be identified by concordance of vegetation with the Clinton coal of Missouri and the Cannelton coal of Pennsylvania, from which we have abundant vegetable remains for comparison.
Of the plants exclusively found in connection with each of these coal beds, Mazon Creek has eighty, Morris twenty-three, Murphysborough nine, Colchester five. The geological station of these four localities is identified by stratigraphy as well as by the analogy of their flora, as seen upon the table. We have therefore for comparison, taking all the plants peculiar to the same horizon in Illinois, one hundred and seventeen species. Of these Cannelton has fifty-six, besides its thirty-eight proper species and Clinton twenty-eight, with eighteen proper species. The relation is thus so intimately marked that if it is not possible to admit the strata as synchronous, it is at least necessary to consider them as pertaining to a same group quite as distinct in the characters of its flora as is the Sub-conglomerate. This group corresponds to A B C of the anthracite and if for future reference called Group A. The species discovered in it amounting already to three hundred and twenty.
§ 54. The Coal strata coming after in the ascending order appear to correspond to the horizon of the Upper Freeport of Pennsylvania or Coal 6 of the Ohio, Indiana and Illinois sections.
Of this horizon we have so few materials that it is not yet possible to present points of comparison between the localities where the few plants have been obtained and to relate them to upper or lower strata. Possibly Coal 1 of Olyphant marked Go on the third column of the Anthracite side of the table may be referable to this horizon. But as yet the coal strata have only three species in common. That the flora is a middle one and has distinct characters is indicated by its species.
Those not found elsewhere: Rhacophyllum inflatum, Stemmatopteris insignis, Lycopodites Ortoni, Lepidodendron forulatum, Lepidodendron Tyjoui, Lepidodendron radicans, Halonia secreta, Lepidophloios auriculatus, Cardiocarpus bicornutus, are, with few exceptions, of peculiar types, as also Pseudopecopteris spinulosa which was found at Duquoin first, and of which small specimens have been obtained in the Anthracite of Rhode Island. The other species of the group are related nearly in equal number to the flora of the lower and tq that of the upper strata.
§ 55. The upper division of the coal, including the bed marked in the anthracite measures as M, in the bituminous as G, constitutes a distinct group, though like the former its flora is not yet represented by sufficient materials.
The number of species known from it is seventy-eight, ,besides five marine Algae. Of this number thirty-four are proper to the group, eighteen in the anthracite, eleven in the bituminous measures, three being found in both. The others, forty-four in number, are diversely distributed mostly in the whole thickness of the true coal measures, as are generally the common species found everywhere.
The more distinct relation is with Morris and Mazon Creek by seven species, with Cannelton by seven also, and with Rhode Island by four; a dozen of these are present in two or three localities: Mazon Creek, Morris, Cannelton, Clinton, etc., while besides the three mentioned above, ten are present both in the anthracite and the bituminous.
§ 56. The anthracite bed of Rhode Island is still left for consideration. Do the plants obtained from it indicate its geological station? We have from the coal twenty-seven species, three of which only are proper to it; of the others, twenty are identified in the group A. Though a number of them are of wide distribution, the reference of the coal of Rhode Island to the lower group A seems positive, so far as one may rely on evidence based on such scanty materials.