Palynology of a wealden section (Lower Cretaceous) in the “Carrière de Longueville”, the Boulonnais (France)

Review of Palaeobotany and Palynology Elsevier Publishing Company, Amsterdam - Printed in The Netherlands

PALYNOLOGY OF A WEALDEN SECTION (LOWER CRETACEOUS) IN THE "CARRIERE DE LONGUEVILLE", THE BOULONNAIS (FRANCE) G. F. W. H E R N G R E E N 1

Institute of Earth Sciences, Free University, Amsterdam (The Netherlands) (Received March 10, 1970) (Resubmitted September 24, 1970)

SUMMARY

This article deals with the pollen-and-spore content of samples which have been derived from two sections, one above and one below a palaeosol in the "Carri6re de Longueville", the Boulonnais region, northwestern France. The sediments exposed in this quarry, are part of the Lower Cretaceous sequence in the so-called Wealden facies, the age of which is, according to the geologic map of France, post-Portlandian and pre-Aptian. Fifty-one different species have been found, most of them belong to well known genera from western Europe and North America; five species are newly described. There are striking qualitative (local range of various species) and quantitative differences, and on this basis the pollen diagram has been divided into two pollenzones A and B, respectively below and above the palaeosol. Interpretation of the palynological data has led the author to the following palaeophytogeographical considerations: a mixed flora of ferns-partly Gleicheniidites- preceeded pedogenesis, which was followed by a pioneer vegetation of mainly Gleicheniidites. The age of the investigated part of the "Wealden" strata is Upper Barremian or Lower Aptian. INTRODUCTION

This paper describes the results of a palynological investigation of a section, sampled in June 1967, in the "Carri~re de Longueville", which is situated in the valley of the "R ~u' de Hamy" near Nabringhen, the Boulonnais, northwestern France (Fig.l).

1 Present address: Rijks Geologische Dienst, Spaarne 17, Haarlem (The Netherlands).

Re~ Palaeobotan. Palynol., 12 (1971) 271-302

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FRANCE Colembert

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Fig. 1. Upper right: map of France; the Boulonnais region is marked with a black spot. Enlargement: the hammers indicate the "Carri6re de Longueville",

In the Boulonnais region occur continental deposits in the Wealden facies, containing plant debris. They were deposited on Purbeckian sands and are superposed by Aptian sands. These sediments are indicated on the geologic map of France as "Wealdien", symbol CIII. The purposes of this investigation are: (1) to present the pollen-and-spore content; (2) to establish eventual palynological differences between the deposits above and below the palaeosol (Fig.3); (3) to obtain if possible, a more detailed chronostratigraphic position than "Wealdien". MATERIALS AND METHODS

Sampling procedure and processed samples The quarry is operated on red and grey clay. Two horizons (palaeosols) are of interest for the exploitation, so there are two steps excavated in the quarry wall (Fig.3). In total 161 samples were collected and 83 of them were prepared (Fig.3). Samples with sufficient sporomorphs for counting are concentrated in two levels: a section of 70 cm above palaeosol I with 37 processed samples, 11 were cot~nted; another section of 53 cm below this palaeosol with 8 processed samples, 6 were counted. 272

Rev. Palaeobotan. Palynol., 12 (1971) 271-302

Slide preparation The samples consist of sand, clayey sand and clay. Several preparation techniques were tried experimentally on larger samples. By the process of elimination, the author finally settled on the following procedure with ca. 1 cm 3 of each sample: 10~o KOH, the KOH treatment dissolves humic matter, 36-40~o HF, bromoform separation (s.g. 2.0), followed by acetolysis, this treatment removes cellulosic matter and also has possible a staining effect on exines. After diluting the organic residue with silicone oil (r.i. = 1.4), one drop of the mixture was added to a slide, a cover-glass was mounted and sealed with paraffin. Microscope analysis and preservation of samples and slides Determinations and countings are made with a Leitz Laborlux binocular microscope nr. 698349 (laboratory number APO 4), objectives 25 x, 40 x and 100 x ; oculars GF I0 x and Leitz ocular-micrometer 12.5 x, laboratory number APO 16. Slides, processed residues, unprocessed portions of samples and unprocessed samples are stored at the Institute of Earth Sciences, Free University, Amsterdam. Slides with holotypes have been designated by the number in the Amsterdam Type Collection (A.T.C.) and are deposited in the collections of the Hugo de Vries Laboratory, Department of Palynology, University of Amsterdam. Consulted literature for determination of the pollen grains and spores For determination of the pollen grains and spores the following publications were used (for full title, periodical, volume number and pages or place of publication, see MANTEN, 1970): BALME,B. E., 1957b; BoLfnovmya, N. A., 1961, 1966; BOLTENHAGEN, E., 1968; BRENNER,G. J., 1963; COOKSON,1. C. and DETTMANN, M. E., 1957, 1961; COUPER,R. A., 1953c, 1955, 1958; DANZIg,J. and LAVEINE,J. P., 1963; DELCOURT,A., DETTMANN,M. E. and HUGHES,N. F., 1963; DELCOURT,A. and SPRUMONT,G., 1955, 1957b, 1959a, 1959b; DOmNG, H., 1965a; HUGHES,N. F., 1955; HUGHES,N. F. and MOODY-STUART,J. C., 1969; JARDIN~, S. and MAGLOIRE, L., 1965; KREMP, G. O. W. (Editor) 195%1968; LANTZ, J., 1958a, 1958b; LEVETCARETTE, J., 1963, 1964a; NmSSON, T., 1958b; NORRIS, G., 1969; PIERCE, R. L., 196l; POTONI~, R., 1956c, 1958b, 1960b, 1966; REYRE, Y., 1964; STANLEY, E. A., 1965c; VENKATACHALA,B. S. and GOcz/~N, F., 1964; VON DER BRELIE,G., 1964. LITHOLOGY

General lithology and sporomorph content In this chapter a short description is given of the lithology of the samples in the quarry and their sporomorph content (Fig.3). Rev. Palaeobotan. Palynol., 12 (1971) 271-302

273

The samples L1-L17, K1-K41 and K56-K67 consist of ferruginous clayey sand to sand, sometimes, K15-K23 and K59-K65, whitish to light grey sand alternating with clayey sand and ferruginous sandy laminae. These samples yielded no sporomorphs. In the section K42-A1 plant debris are regularly macroscopically visible in the overall sandy to clayey sandy samples. Only in K52 and K55, respectively fine whitish sand and coarse ferruginous sand with plant fragments, sufficiently sporomorphs for counting are available. The samples A2-A5 and 1-31 mainly consist of dark grey to black sandy clay with locally plant debris. They contain abundant sporomorphs. In the ferruginous sandy samples 32-36 no sporomorphs have been found. The next 275 cm reveals from top to bottom the following succession: 85 cm light grey to whitish leached clay; 50 cm red clay, samples I1 and 12; with indistinct and irregular changes, this layer passes into: 60 cm yellow to ocreous clay, samples HI and H2; 25 cm red clay, sample H3; 50 cm light grey to whitish leached clay, samples G1-G4. The samples I2, H2 and G2 were processed but yielded no sporomorphs. At least I consider the uppermost red clay horizon and transition to yellow colored strata as a burried fossil soil (palaeosol). Then follows a dark grey sandy clay to clayey sand of about 10-20 cm, locally 110 cm where the samples El-E23 were taken with the Edelman drill. All were processed but only the top, samples El-E8, yielded (abundant) sporomorphs. These sediments are underlain by a red clay (palaeosol II) 3-4 m down to the floor of the quarry. At - 5 5 cm (F1) to - 9 5 cm (F3) occurs grey sandy clay with some sporomorphs, which were however insufficient for counting. X-ray analysis

Six samples were studied on their claymineral composition by means of X-ray analysis with focussing Guinier-De Wolff powder camera: K46,6 and 29 above palaeosol I, E5 and E8 below this palaeosol and sample I2 which represents the palaeosol (Fig.2). Results of interest for the present study are summarized as follows: (1) There is no clear difference between the various samples. (2) Sample I2 (palaeosol) does not differ from the parent material, samples E5 and E8 below palaeosol I, which leads to the conclusion that the pedogenesis was very short and/or not intensive. (3) No indication for marine alteration of the clay minerals was found.

274

Rev. Palaeobotan.PalynoL, 12 (1971) 271-302

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The Boulonnais Wealden deposits represent on the European continent the easterly prolongation of the Weald in southeast England. Tectonically they form part of a northwest-southeast trending anticlinal structure in Cretaceous and Tertiary sediments, often indicated as Weald-axis. Since the Devonian period the region was subjected to many phases of tectonic activity separated by periods of denudation or transgression of the sea. After the Hercynian movements continental deposits of Triassic age were accumulated locally in the depressions of the partly dissolved Vis6an limestones. Afterwards the Jurassic sea transgraded the Boulonnais mainly during the Bathonian (Middle Jurassic); till the Portlandian (Upper Jurassic) the region was submerged. During the deposition of the Purbeck beds regression took place as a result of the Boulonnais phase, and the Lower Cretaceous sediments of continental origin (Wealden facies) accumulated. During the Aptian the sea re-advanced and marine sedimentation continued throughout Upper Cretaceous up to the Eocene. Alpine movements caused the anticlinal stucture of the Weald-Boulonnais-Artois region.

Regional stratigraphy The Upper Portlandian sands and calcareous sandstones with the ammonites Perisphinctes bononiensis, P.giganteus, P.gorei, P.lapideus, P.pseudogigas and the pelecypoda Cardium, Astarte and Trigonia are superposed by: (/) Purbeckian (0-3 m) sands with calcareous concretions yielding Anisocardia socialis and Candona bononiensis. (2) Wealden (20-30 m) continental deposits of sand, ferruginous (coarse) sands, occasionally showing cross-bedding, clayey sands and red and grey clay with lignitic intercalations. These strata contain Cyrena mantelli, C.media, C.tom-

Rev. Palaeobotan.Palynol., 12 (1971) 271-302

275

becki and Unio valdens&. On the eroded surface of the Wealden sediments rest: (3) Aptian; "Sables de Saint-Etienne au Mont" original glauconitic sands, now weathered yellow brown ferruginous sands with Corbula striatula, Astarte subcostata, Exogyra tombecki and Thracia phillipsi, followed by "Sables verts et argiles glauconieuses de Wissant" consisting of a basal conglomerate and clayey glauconitic sands with Ostrea leymeriei, Exogyra aquila, Trigonia aliformis and Rhynchonella gibbsi (PRUVOST and PRINGLE, 1924). ARKELL (1956), dealing with the problem of the stratigrafical position of the lower part of the abovementioned section, referred the Purbeckian sands to the Lower Purbeck of England. He correlates the Wealden of the Boulonnais with the Weald Clay--probably in the sense of Wealden Beds, the interval between Purbeck Beds and Aptian Lower Greensand Formation--of southern England. More recently, new palynological data have offered more information about the age of the British "Wealden". HUGHES (1958) reached the general conclusion that the succession of the Weald area is probably complete through Valanginian to Barremian; the upper part of Weald Clay III at least must be within the lower part of the Aptian Stage. This conclusion is confirmed by ANDERSON and HUGHES (1964); and they correlate the Wealden facies with the marine deposits in Lincolnshire, Yorkshire and Norfolk. ALLEN (1967) assignes the Hastings Beds, the lower part of the English Wealden, to the Valanginian stage and correlates the Weald Clay, the upper part, with the Hauterivian and Barremian stages. THE POLLENFLORAAND THE POLLENDIAGRAMS

Composition of the pollen diagrams The samples of the section above palaeosol I comprise a sedimentary sequence with a thickness of 70 cm, the samples below this palaeosol cover a section of 50 cm. From the data of the quantitative sporomorph investigations two types of diagrams were composed: (1) A cumulative diagram by taking the sum of all components on 100~. Fig.5 shows the mutual relations between: Gleicheniidites, bisaccate forms (Vitreisporites, Parvisaccites, Podocarpidites and decayed bisaccates), rest group (comprising other Triletes, Aletes and Aporatae, rest saccate forms, Monoporatae and Praecolpatae) and indeterminable spores (supposed mainly to be strongly corroded Gleicheniidites and small, corroded Cyathidites). (2) Gleicheniidites is dominating in many spectra and obscures several other features which are of importance. Therefore separate curves (Fig.4) which represent the frequencies of each individual sporomorph were constructed by excluding Gleicheniidites and indeterminable spores and taking the sum of all other components on 100K. 276

Rev. Palaeobotan.Palynol., 12 (1971) 271-302

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Description of the pollen zones On appearance and disappearance of species and on the frequency fluctuations of some major species in the cumulative and separate diagrams (Fig.4, 5) the pollen diagram is provisionally subdivided into pollen zone A below palaeosol I and pollen zone B above this palaeosol. These two zones show striking differences. Rev. Palaeobotan. Palynol., 12 (1971) 271-302

283

Pollen zone A First of all I consider the cumulative diagram (Fig.5). Gleicheniidites fluctuates from 29-44.9 ~o; it is difficult to describe the oscillations in this curve because of the unknown influence of the indeterminable spores (most of them are believed to be strongly corroded Gleicheniidites). The bisaccates fluctuate from 13.4-22.3 ~ with a general increase in E6a +b, E5b and E4b. Rest group: striking are the high values, from 46.1 ~o in E8a with an overall decrease to 2 8 ~ in Ela. The bulk of the sporomorphs consists of the dominants Cyathidites (Fig.4, graph 5) and Trilobosporites canadensis (22), and the subdominants Cicatricosisporites (10), Concavissimisporites (19) and Pilosisporites (29). If we consider the separate curves (Fig.4) the main characteristics are: high values of Cyathidites 22.2-44~ (5), Trilobosporites canadensis 9.8-24.7°J(, (22), Pilosisporites trichopapillosus 2.2-9.8 ~ (29) and Parvisaccites radiatus 19.4-33.3 (41); presence of Cicatricosisporites exiguus (10), Concavissimisporites (19) and Equisetosporites (34, 35); and low values of Classopollis (47). Pollen zone A has been subdivided into two subzones AI and A2 on the basis of: (1) Cicatricosisporites exiguus (10) fluctuates from 4-9.1 ~o in A1 and shows a decrease in A2 to 0.7-0~/o. (2) Concavissimisporites 3.6-7.7 ~o (19) in A1 shows a considerable decrease to 1-0.2 ~ in A2. This is due to a strong decrease of Coneavissimisporites minimus. (3) Trilobosporites canadensis 9.8-12.6 ~o (22) in A1 has a sharp rise to 20.724.7 ~ in A2. (4) Pilosisporites trichopapillosus 2.2-4.5~o (29) in A1 has an increase to 7.3-9.8 ~o in A2. It is very remarkable that the increase of Trilobosporites canadensis (22) and Pilosisporites trichopapillosus (29) in E4b and E la follows the decrease of Concavissimisporites (19) and C.exiguus (10) in E5b, E4b and Ela.

Pollen zone B Characteristic is the dominance of Gleicheniidites (Fig.5) which is fairly constant (64.1-72.1 ~o). It is believed that the group of the indeterminable spores is of minor influence (the majority seems to be corroded Gleicheniidites). The bisaccates including in this case Vitreisporitespallidus (Fig.4, graph 39) show some minor fluctuations between 30b and A2, and a sudden increase in K55a + b and K52b, this is caused by the increase ofParvisaccites radiatus (41). The rest group is moderately represented in all samples~ except a distinct rise in 2a and A2 up to 14.3 ~o, followed by a sudden fall in K55a + b and K52b to 5.5-6.5 ~o. The group as a whole is mainly composed of Cyathidites (5), Psilatriletes (6), Plicatella (9) and Cerebropollenites mesozoicus (45); Trilobosporites canadensis (22) and Pilosisporites trichopapillosus (29) are also important. 284

Rev. Palaeobotan. Palynol., 12 (1971) 271-302

The separate curves, compared with those of pollen zone A, reveal other important features: (1) Higher values of Parvisaccites radiatus 35.8-70.5 ~ (41). (2) An increase of Lycopodiumsporites semireticulatus up to 2.8 ~ (16) and Classopollis up to 5.1 ~o (47). (3) Equisetosporites ovatus (34) and E. sp. E.? albertensis (35) disappear; Concavissimisporites (19) is practically absent (only some strongly corroded specimens are found). (4) Strong decrease of Cicatricosisporites exiguus (10). (5) Characteristic of this pollen zone is the appearance of: Sphagnumsporites antiquasporites (1), Clavifera triplex (3), Psilatriletes sp. (6) Klukisporites variegatus (17), Osmundacidites wellmanii (28), Vitreisporitespallidus (39) and Cerebropollenites mesozoicus (45) of this species also some corroded specimens have been counted in pollen zone A. Pollen zone B can be subdivided into two subzones: B1 which consists of sandy clay and B2, clayey ferruginous sand, on the basis of: (1) Sharp rise of Parvisaccites radiatus 35.8-47.8 ~o (41) in B1 to ca. 70~o in B2 and increase of Trilobosporites canadensis (22). (2) Distinct fall of Vitreisporites pallidus 5.7-8.9 ~o (39) in BI to 0.7-0~o in B2 and of Cerebropollenites mesozoicus 2.1-5.6 ~o (45) in B1 to 0.5-0 ~o in B2. (3) Disappearance of Sphagnumsporites antiquasporites (1), Psilatriletes (6), Plicatella (9) and Osmundacidites wellmanii (28). In both pollen zones sometimes corroded sporomorphs have been found which may be reworked from older deposits e.g., Concavissimisporites minimus in pollen zone B, which is characteristic in zone A, and e.g. some poorly conserved Vitreisporitespallidus grains have been counted in pollen zone A, these are supposed to be reworked from older strata. This is indicated in the curves by a dashed line. As a matter of fact I cannot be sure of the wider significance of the pollen zones and their subdivisions until more and longer Wealden-sections are known from the area; hence I used the provisional letter indications. PALEOPHYTOGEOGRAPHICINTERPRETATION As a rule no attempt has been made to establish the natural relationship of our pollen g~ains and spores. An exception is made for Gleicheniidites Ross, 1949, one of the most characteristic spores. Several authors (Ross, 1949; CooKsoN, 1953; BOLCHOVITINA,1953 and others) assign gleicheniid spores to the recent genus Gleichenia. According to HOLTTVM(1957) the fern family Gleicheniaceae consists of two subfamilies: (1) Gleichenoideae with two genera, Gleiehenia J. E. SMITH (with three subgenera and about 120 species) and Dicranopteris BERNHARDI (with two subgenera and about 10 species). SKARBV (1964) points out that it is impossible to refer the

Rev. Palaeobotan. Palynol., 12 (1971) 271-302

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fossil trilete gleicheniid spores to one of these living genera, both having monolete and trilete spores. She assembles all fossil gleicheniid spores with the characteristic features in the organ genus Gleicheniidites Ross, 1949, family Gleicheniaceae. (2) Stromatopteroidea comprise only one genus with one species with monolete spores. According to COPELAND (1947) and HOLTTUM (1954) the modern Gleicheniaceae are: "terrestrial ferns; tropical and subtropic (except northern Africa) and in the southern hemisphere far into the temperate zone". There are two other important considerations (see also Ross, 1949): (1) modern Gleicheniaceae are rich spore producers; (2) both recent and fossil Gleicheniaceae are herbaceous plants. The dominance in at least pollen zone B, is so great (ca. 64-72 ~ ) that it may suggest an important local Gleicheniidites vegetation, with nearby deposition of the spores. POCOCK (1962) assumes that Classopollis occured in coastal regions with a locally abundant pollen production, so the low values of Classopollis in this section may indicate some distance rcehind the coast. The other features also, as the overall good conservation of the sporomorphs, the horizontal layered sediments and the absence of marine alteration of the clay minerals, seem to stress a deposition of the sporomorphs in an upper deltaic environment e.g. deltaic lakes. This hypothesis is confirmed by the absence of dinoflagellates. HOLTTUM(1954) states: "The Malayan species of Gleichenia form thickets in open places, or on the edges of forest, never in forest shade. They sometimes cover the ground so densely that no other plant can grow, but if tree seedlings grow with them the trees may in time shade the Gleichenia out of existence" and Ross (1949) reports: "certain recent Gleicheniae are known as bad weeds which rapidly colonize clearings and burn-beaten lands, surpressing other plants with their thick leafage". The 2 9 - 4 5 ~ Gleicheniidites and 4 6 - 2 8 ~ rest group of pollen zone A might suggest a mixed flora, which after pedogenesis, was followed by recolonization: a pioneer vegetation of Gleicheniidites (high values, up to 64-72 ~ in pollen zone B), analogous to the modern invasions of Gleichenia pointed out by Ross (1949). The 12-22~o bisaccate grains (Fig.5) may indicate that the gymnosperms e.g. Parvisaccites radiatus and Vitreisporites pallidus did not grow on the spot; although there is no evidence at all for the distance on which these land plants occurred. AGE DETERMINATION For the purpose of age determination several data assembled from the literature on the regional stratigraphy and on the distribution of species (Fig.6) are summarized and compared with the results of this study: (1) On the basis of the regional stratigraphy the Boulonnais Wealden deposits are post-Portlandian and pre-Aptian. 286

Rev. Palaeobotan. Palynol., 12 (1971) 271-302

Jurassic

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T.bernissartensis r.canadensis Aequitriradites Chomotriletes fragilis Foveotriletes subtrianguloris Equlsetosporites ovatus E. albertensis

I J I ] I I [ I I I I I Fig.6. Time-range table of some of the described species.

(2) All described sporomorphs belong to the ?Bryophyta (Sphagnumsporites antiquasporites), Pteridophyta and Gymnosperms. No pollen grains of angiospermous origin were found. Although this negative evidence it may point to a preAlbian age. (3) The flora as a whole is a typical Lower Cretaceous one (Fig.6). (4) An abundance of Parvisaccites radiatus was reported by COUPER and HU~HES (1963)from The Netherlands and adjacent areas and considered to be indicative for a Barremian age. (5) The presence of such species as Equisetosporites ovatus and E. ?albertensis and other Ephedra like types have proved to be of wide time-stratigraphical significance. Their first appearance in the Upper Barremian, has been described e.g., by SINGH (1964) from the Ellerslie Member, Mc.Murray Formation, Alberta, Canada. (6) Trilobosporites bernissartensis leaves the geological record early in the Aptian age (Fig.6). Comparison of the above mentioned data strongly suggests an Upper Barremian or Lower Aptian age of the "Wealden" strata in the "Carri~re de Longueville". Rev. Palaeobotan. Palynol., 12 (1971) 271-302

287

SYSTEMATIC PALYNOLOGY

General systematics and species list The species mentioned in the following list occur in the Lower Cretaceous sediments of the "Carri~re de Longueville", the Boulonnais, France. No attempt has been made to arrange the spores and pollen grains according to a natural classification. I used, for convenience sake only, the artificial scheme as designed by BURCER (1966), with some minor emendations. The author's name is followed by the plate and figure number of the photographs given in this report. New species and supplementary descriptions of existing species are treated in the following section on systematic descriptions. Psilatriletes Sphagnumsporites antiquasporites (WILSON et WEBSTER)POCOCK, 1962 (Plate 1,1 ) Deltoidospora rafaeli BURGER, 1966 (Plate 1,2) Cyathidites sp. (Plate 1,3) Gleicheniidites senonicus Ross, 1949 (Plate 1,4) Clavifera triplex (BOLCHOVmNA) BOLCHOVmNA, 1966 (Plate 1,5) Matonisporites phlebopteroides COUPER, 1958 (Plate 1,6) Psilatriletes sp. (Plate 1,7) Striatriletes and Rugutriletes Plicatella sp.1 (Plate 1,8-11) Plicatella sp.2 cf. P.trieornitata (Plate I, 12,13) Cicatricosisporites exiguus nov. sp. (Plate 1,14~16) Cicatricosisporites sp. (Plate 1,17) Chomotriletes fragilis PofocK, 1962 (Plate II, 1)

PLATE I

1. 2. 3. 4. 5. 6. 7. 8-11.

Sphagnumsporites antiquasporites, proximal view; x 1,000. Deltoidospora rafaeli, proximal-equatorial view; × 1,000. Cyathidites sp., proximal view; x 1,000. Gleicheniidites senonicus, equatorial view; x 1,000. Clavifera triplex, equatorial view, thickened exine and spherical processes; x 1,000. Matonisporites phlebopteroides, equatorial view; x 1,000. Psilatriletes sp., equatorial view, thick exine and margo; x 1,000. Plicatellasp. I; x 1,000. 8. proximal-equatorial view of type 1; 9. distal view of type 1; 10. proximal view of type 2; 11. distal view of type 2. 12, 13 Plicatella sp. 2 cf. P.trieornitata; x 1,000. 12. proximal view; 13. distal view. 14-16. Cicatricosisporites exiguus nov. sp., holotype; x 1,000. 14. proximal view; 15. equatorial view; 16. distal view. 17. Cicatricosisporites sp.; x 1,000.

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PLATE I

7

,

17

Foveotriletes and Retitriletes

Foveotriletes subtriangularis BRENNER, 1963 (Plate 11,2) Lycopodiumsporites austroclavatidites COOI,:SON, 1953 (Plate II,3) Lycopodiumsporites semireticulatus BURGER, 1966 (Plate II,4,5) Klukisporites variegatus COUPER, 1958 (Plate ll,6) Microreticulatisporites sp. aft. M.uniformis SINGH, 1964 (Plate II,7) Scabratriletes, Verrutriletes and Gemmatriletes Concavissimisporites minimus nov. sp. (Plate 11,8-10) Concavissimisporites sp. (Plate II,11,12) Converrucosisporites proxigranulatus BRENNER, 1963 (Plate 11,13) Trilobosporites apiverrucatus COUPER, 1958; form A (Plate 11,14,15) form B (Plate I1,16-18) Trilobosporites bernissartensis (DEL¢OUR'r et SPRUMONT) POa'ON~, 1956 (Plate 1II,1) Trilobosporites canadensis PococK, 1962 (Plate 111,24) Trilobosporites boulonnensis nov. sp. (Plate I11,5-7) Trilobosporites sp. (Plate II1,8,9) Verrucosisporites obscurilaesuratus POCOCK, 1962 (Plate 111,10,11) Bacutriletes and Echitriletes

Osmundacidites wellmanii COUPER, 1953 (Plate 111,12) Pilosisporites trichopapillosus (THIERGART)DELCOURTet SPRUMONT,1955 (Plate Ili, 13 ;IV, 1) Zonoechitriletes, Zonorugutriletes and Zonoretitriletes Aequitriradites spinulosus (CooKSON et DE'ra-r~ANN) COOKSONet DETTMANN, 1961 (Plate II1,14;IV,2) Aequitriradites macroechinatus nov. sp. (Plate IV,3-5) Densoisporites microrugulatus BRENNER, 1963 (Plate IV,6) Cingulatisporites foveolatus COUPER, 1958 Januasporites sp. (Plate V,I 3) lnaperturates

Equisetosporites ovatus (PIERCE) SIN~3H, 1964 (Plate IV,7,8) Equisetosporites sp.E. ? albertensis SIN~H, 1964 (Plate IV,9) Ephedripites types

PLATE II I.

2. 3. 4,5.

Chomotriletes fragilis, concentric striae; × 1,000. Foveotriletes subtriangularis, equatorial view; × 1,000. Lycopodiumsporites austroclavatidites, reticulum of distal side; × 1,000. Lycopodiumsporites semireticulatus; × 1,000.

4. distal view; 5. equatorial view. Klukisporites variegatus, distal view; × 1,000. Microreticulatisporites sp., aft. M.uniformis, reticulum of distal side; × 1,000. 7. 8-10. Concavissimisporites minimus nov. sp., holotype; × 1,000. 8. proximal view, small verrucae and margo; 9. equatorial view, thickened exine between the corners; 10. distal view, small verrucae. 11, 12. Concavissimisporites sp.; × 1,000. 11. proximal view, sharply ending margo, exine psilate to smooth; 12. equatorial view, thickened exine between the corners. 13. Converrucosisporites proxigranulatus, distal view; × 1,000. 14-18 Trilobosporites apiverrucatus. 14. form A, proximal view; × 400; 15. form A, detail of corner verrucae; × 1,000; 16. form B, proximal view; × 400; 17. form B, margo; × 1,000; 18. form B, detail of corner verrucae; × 1,000. 6.

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PLATE

II

2

o-?, i!i~7¸

L

Psilamonovesiculatae

Applanopsis dampieri (BALME) DORING, 1961 (Plate IV,10) Psilabivesiculatae

Vitreisporites pallidus (REISS1NGER) NILSSON, 1958 (Plate IV, 1l) Rugubivesiculatae

Ru~ubivesiculites minimus BURGER, 1966 (Plate IV, 12,13) Parvisaccites radiatus COUPER, 1958 (Plate I V, 14;V,1) Scabravesiculatae

Podocarpidites sp. cf. P.radiatus BRENNER, 1963 (Plate V,2) Scabrapolyvesiculatae

Applanopsis trilobatus (BALME) GOUBIN, TAUGOURDEAUet BALME, 1965 (Plate V,3) Psilapolyvesiculatae

Cerebropollenites mesozoicus (CouPER) NILSSON, 1958 (Plate V,4) Psilamonoporates

Spheripollenites sp. (Plate V,5) Endostriatae

ClassopoHis sp. (Plate V,6) Classopollis minimus nov. sp. (Plate V,7,8) Psilapraecolpates

Eucommiidites minor GROOT et PENNY, 1960 (Plate V,9) Incertae sedis Form A (Plate V,10) Form B (Plate V,11,12) Form C (Plate 1V,15,16) M egaspo res aft. Minerisporites (Plate V, 14-16)

PLATE IIl

I.

Trilobosporites bernissartensis, proximal view, trilete mark, margo, verrucae and apical caps; × 1,000.

2 4. 5-7.

8, 9.

Trilobosporites canadensis. 2. proximal view; x 400; 3. detail of corner verrucae; x 1,000; 4. proximal view of another specimen; × 1,000. Trilobosporites boulonnensis nov. sp.; x 1,000. 5. holotype, proximal view, trilete mark and margo; 6. holotype, equatorial view, verrucae; 7. proximal view of another specimen. Trilobosporites sp.; x 1,000. 8. proximal view, trilete mark bordered by a margo of fused verrucae; 9. equatorial view, slightly thickened exine in the apical regions.

10, 11. Verrucosisporites obscurilaesuratus; • 1,000. 10. proximal view, trilete mark; 11. proximal view, trilete mark and verrueae. 12. Osmundacidites wellmanii, gemmae-clavae; x 1,000. 13. Pilosisporites trichopapillosus; × 400. 14. Aequitriradites spinulosus, proximal view; x 400.

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PLATE

III

|

Systematic descriptions

Genus Plicatella MALIAVK1NA, 1949 Plicatella sp. 1 (Plate 1,8-1 I) Description. Trilete, amb triangular with convex sides and pointed (type I; Plate 1,8 proximal view, 9 distal view) or hemispherical protruding corners (type 2; Plate 1,10 proximal view, 11 distal view). Exine on both faces striate, ribs running parallel to the adjacent sides, forming a pattern o f concentric triangles. At distal face 4-5 triangles, ribs 2-3/1 wide and set apart 1-3/1. At proximal face 5-?7 triangles. Near the corners the ribs curve outwards and fuse, thus causing the typical protrusions. Apices hemispherical with a diameter o f 5/~ or elongated

9-12p long and 3/1 wide. Dimensions. 35-50/l. Plicatella sp. 2 (Plate 1,12, 13) Description. Trilete, arab triangular with convex sides and blunt to hemispherical protruding corners. Exine on both faces striate, ribs at proximal face in 3 concentric triangles, 2-3/1 wide and set apart 2-3//. At the distal face about 7 concentric triangles, ribs 1.5/1 wide and set apart ca. 1/1.

PLATE IV Pilosisporites trichopapillosus, baculae; x 1,000. Aequitriradites spinulosus, distal view, detail of central body; x 1,000. Aequitriradites macroechinatus nov. sp., holotype. 3. equatorial view, vaguely showing the trilete mark; × 500; 4. distal view, echinae and hollow bosses; x 1,000. 5. ditto. 6. Densoisporites microrugulatus, proximal-equatorial view; × 1,000. 7,8. Equisetosporites ovatus; × 1,000. 7. ridges and furrows (striae); 8. polar field. 9, Equisetosporites sp. E. ? albertensis, striae near the pole; × 1,000. 10. Applanopsis dampieri; x 1,000. II. Vitreisporites pallidus; x 1,000. 12-13. Rugubivesiculites minimus; × 1,000. 12. lateral view, rugulae of proximal cap; 13. air sacs in lateral view. 14. Parvisaccites radiatus, lateral view; x 1,000. 15-16. Incertae sedis, form C; x 1,000. 15. equatorial view; 16. distal view. I,

2. 3-5.

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PLATE IV

~

4

Dimensions. 4045/~. Comments. This grain has affinity to Plicatella tricornitata (WEYLArqO et GRElFELD) POTONI~, 1960.

Occurrence. Both grains are c o m m o n , in total 4.5-10.3 ~o, in pollen zone B; only twice an indistinct Plicatella has been c o u n t e d in zone A. Age and locality. Lower Cretaceous; W e a l d e n deposits in the " C a r r i 6 r e de Longueville", Boulonnais, France.

Remarks. Plicatella sp. 1 a n d sp. 2 have been c o u n t e d together in the d i a g r a m , because in c o r r o d e d specimens they are difficult to distinguish. G e n u s Cicatricosisporites POTONII~ et GELLETICr~, 1933

Cicatricosisporites exiguus nov. sp. (Plate 1,14-16; respectively proximal-, e q u a t o r i a l - a n d distal view) Derivatio nominis. N a m e derived from the small grain size. Holotype. Slide E8a, c o o r d i n a t e s 111.4-43.3,A.T.C. 145. Description. Trilete, a m b t r i a n g u l a r with s t l a i g h t to convex sides. Trilete m a r k reaching the equator. Exine on b o t h faces striate; p r o x i m a l l y 2-3 concentric triangles, ribs r u n n i n g parallel to the adjacent sides. A r o u n d the proxi-

PLATE V 1.

2.

Parvisaccites radiatus, distal view; x 1,000. Podocarpidites sp. cf. P.radiatus, distal view, radial arrangement of the muri at the bases

of the air sacs; x 1,000. Applanopsis trilobatus; x 1,000. 4. Cerebropollenites mesozoicus; x 1,000. 5. Spheripollenites sp.; x 1,000. Classopollis sp.; x 1,000. 6. Classopollis minimus nov. sp., holotype; × 1,000. 7-8. 7. distal circular area; 8. columellae. 9. Eucommiidites minor; × 1,000. 10. lncertae sedis, form A, trilete mark and densely packed verrucae; × 1,000. 11-12. Incertae sedis, form B; x 1,000. 11. echinae; 12. exine and echinae. Januasporites sp., reticulum of central body and membraneous layer; × 1,000. 13. 14-16. aft. Minerisporites. 14. proximal-equatorial view; × 250; 15. distal view; × 250; 16. detail of corner, fold like elements of the perinous layer; x 1,000. 3.

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PLATE V

r ~12

16

mal pole a contact area is left free of about 3.5#. At distal face the ribs diverge from one corner and cover the distal face for about 3/4, these ribs are blotted out by a set of 3 ribs, running parallel to the opposite side. Ribs 1.5(1.6)1.9# wide and set apart 0.5#.

Dimensions. 20(23-25)32#. o/ Occurrence. Frequent, 4-9.1 ~ in pollen zone A l", rare, 0.7/o, in zone A2.

Age and locality. Lower Cretaceous; Wealden deposits in the "Carri~re de Longueville," Boulonnais, France. Remarks. The grains of C. exiguus are smaller than thos of other described species of Cicatricosisporites. Genus Concavissimisporites (DELCOURT et SPRUMONT) DELCOURT, DETTMANN et HUGHES,1963.

Concavissimisporites minimus nov. sp. (Plate 11,8-10; respectively proximal-, equatorial- and distal view) Derivatio nominis. Name derived from the small grain size. Holotype. Slide E8a, coordinates 112.2-42.7,A,T.C. 146. Description. Trilete, amb triangular with concave sides and broad rounded corners. Laesurae 6/10--9/10 radius of spore, bordered by a distinct margo ca. 3# wide and narrowing sharply towards its ends. Exine verrucate, verrucae very flat, 0.8-1.5# in diameter and spaced 0.5-1# apart. Exine thickness 1.4-2.4# at the corners, increasing to 2-3.2# midway between the corners. Dimensions. 20(36-40)50#. Occurrence. Common, up to 7 %, in the lower part of pollen zone A. Age and locality. Lower Cretaceous; Wealden deposits in the "Carri~re de Longueville", Boulonnais, France. Remarks. This grain differs from C.crassatus (DELcOURT et SPRUMONT)DELCOURT DETTMANN et HUGHES,1963 in smaller verrucae and smaller grain size. 298

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Genus Trilobosporites (PANT) POTONI~, 1956

Trilobosporites boulonnensis nov. sp. (Plate IlI,5, 6; proximal- and equatorial view holotype; Plate III,7) Derivatio nominis. Name derived from the Boulonnais region. Holotype. Slide 2a, coordinates 101.4-28.2,A.T.C.147. Description. Trilete, amb triangular with concave sides and rounded corners. Trilete mark 2/3 radius of spore to nearly reaching the equator, bordered by a single row of fused verrucae forming a thickened wall 3~.5/~ wide. Exine verrucate, verrucae 2(3-3.5)4.5/~ across and 0.3(0.7)1.5# high. Total exine thickness ca. 3/~. Dimensions. 40-58/~. Occurrence. Rare, up to 0.6 ~ , in both pollen zones A and B. Age and locality. Lower Cretaceous; Wealden deposits in the "Carri6re de Longueville", Boulonnais, France. Remarks. T. boulonnensis differs from T.humilis DELCOURTet SPRUMONT, 1959 and T.marylandensis BRENNER, 1963 by the presence of verrucae on the proximal and distal sides; grana are absent. T.apibaculatus BRENNER, 1963 has large apical baculae. T.crassus BRENNER, 1963 has verrucae and rugulae which are more strongly developed in the apical regions and on the distal side than on the rest of the spore body. T.hannonicus (DELCOURT et SPRUMONT) POTONI~, 1956 and T.bernissartensis (DELCOURT et SPRUMONT)POTONII~, 1956 have verrucate valvae in the radial regions. T.boulonnensis is smaller than T.apiverrucatus CowPER, 1958 and has less pronounced verrucae. T.canadensis PococK 1962 has bigger verrucae in the apical areas. Genus Aequitriradites (DELcOURT et SPRUMONT)COOKSONet DETTMANN, 1961

A equitriradites rnacroechinatus nov. sp. (Plate 1V,3-5) Derivatio nominis. Name derived from the big spines. Holotype. Slide 25b, coordinates 107-47.1,A.T.C.148. Rev. Palaeobotan. Palynol., 12 (1971) 271-302

299

Description. Trilete, zonate grain. Arab triangular with convex sides. Spore comprises a circular central body with a trilete mark reaching the equator, surrounded by a membranous zona. Exine of the distal face two layered, endexine ca. 0.5/t, ektexine ca. 3/~, strongly sculptured with scattered echinae 4(7-11)16/t long and 2(4)6.5/* wide at their bases; echinae attached on hollow, rounded bosses nearly equal in width to 1.5kt broader as bases of echinae. Proximal face indistinct. Zona scabrate, 6-10/~ at the sides to 10-13/~ at the apices beyond the central body. Size of central body: 58/~. Dimensions. 80/1. Occurrence. Rare, 2 specimens in slide 25b, pollen zone B. Age and locality. Lower Cretaceous; Wealden deposits in the "Carribre de Longueville", Boulonnais, France. Remarks. This grain differs from A.spinulosus (CooKsoN et DETTMANN) COOKSONet DETTMANN,1961, from A.dubius DELCOURXet SeRUMONX, 1955 and from A.variabilis Pococ~:, 1962 by the much bigger and more widely spaced echinae. There is no affinity to Couperisporites complexus (CoUeER) POCOCK, 1962 which is characterized by an outer area sculptured with rugulae and an inner area with polygonal based, hollow bosses capped with spines 0.5/~ wide at their junction. Genus Classopollis (PFLt;G) POCOCK et JAYSONIUS, 1961

Classopollis minimus nov. sp. (Plate V,7, 8; distal view and columellae pattern) Derivatio nominis. Name derived from the small grain size. Holotype. Slide A2, coordinates 108.3-35.2,A.T.C.149. Description. Small monoporate, spherical grain. Exine ca. 1# thick; distal pole showing a circular area in which the endexine is absent, 4-5//in diameter. Tectum complex of structure, columellae 0.5/~ in cross-section, are clearly visible; at the distal side the subequatorial ektexine is reduced (? or loosened); an equatorial band of striae was not observed. Dimensions. 13-16p. Occurrence. Rare, less than 1 ~ in pollen zone A; more common in pollen zone B. Age and locafity. Lower Cretaceous; Wealden deposits in the "Carri~re de Longueville", Boulonnais, France. 300

Rev. Palaeobotan.Palynol., 12 (1971) 271-302

Remarks. I f we accept that there is no equatorial b a n d o f striae (see also BOLTEN-

HAGEN, 1968) this grain belongs to the genus Corollina MALIAW:INA, 1949 or Granuloperculatipollis VENKATACI4ALAet G 6 c z i , N, 1964. But according to POCOCK and JANSONIUS, 1961 the generic description and illustrations o f Corollina are too p o o r and by consequence the genus should not be maintained. The author hesitates to include this grain in the genus Granuloperculatipollis, which is characterized in possessing " a well p r o n o u n c e d granulose ornamentation and a weakly demarcated tenuitas", criteria which I consider more o f specific than of generic rank. Therefore this grain is placed in the genus Classopollis although an equatorial b a n d o f striae was not observed. The grains o f C.minimus are smaller than those o f other described species o f Classopollis. ACKNOWLEDGEMENTS This report is based u p o n fieldwork submitted to the Institute o f Earth Sciences, Free University, Amsterdam. The author wishes to thank Dr. Th. van der H a m m e n (University o f Amsterdam) for his encouragement and use of his well equiped laboratory, where the research was carried out. Prof. Dr. R. Potoni6, Krefeld, Germany) who gave valuable advice about the newly described species, and Mrs. P. M. J. van HoekenKlinkenberg (Geological Survey, Haarlem) for critically reading the manuscript. T h a n k s are also due to Mr. L. W. S. de Graaff (University of Amsterdam) for studying the clay minerals.

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301

HOLTTUM, R. E., 1957. Morphology, growth-habit and classification in the family Gleicheniaceae. Phytomorphology, 7(2): 168-184. HU6HES, N. F., 1958. Paleontological evidence for the age of the English Wealden. Geol. Mag., 95(1): 41-49. MANTEN, A. A. (Editor), 1970. Bibliography of Palaeopalynology 1836-1966. Rev. Palaeobotan. Palynol., 8(1-4): 7-570. POCOCK, S. A. J., 1962. Microfloral analysis and age determination of strata at the Jurassic-Cretaceous boundary in the Western Canada Plains. Palaeontographica, B111(1-3): 1-95. Pococ~:~ S. A. J. and JAyso~ItJS, J., 1961. The pollen genus Classopollis PFLtJG. Micropaleontology, 7(4): 439-443. PRUVOSr, P., 1928. Carte gdologique de France au 80.000 °, feuille 3, Boulogne. Note explicative. Service g6ologique de France. PROVOST, P. and PRIN6LE, J., 1924. A synopsis of the geology of the Boulonnais, including a correlation of the Mesozoic rocks with those of England. Proc. Geol. Assoc., 35:29 67. Ross, N. E., 1949. On a Cretaceous pollen and spore bearing clay deposit of Scania. (A preliminary report). Bull. Geol. lnst. Univ. Uppsala, 34: 25-42. S~NGH, C., 1964. Microflora of the Lower Cretaceous Mannville Group, east-central Alberta. Bull. Res. Council Alberta, 15: 1-328. SKARBY, A., 1964. Revision of Gleicheniidites senonicus Ross. Acta Univ. Stockhohn, 11(3): 59-77.

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