The Jurassic dinoflagellate cyst Gonyaulacysta dentata (Raynaud 1978) Lentin & Vozzhennikova 1990 emend. nov. : an index species for the late Callovian to earliest Oxfordian of the northern hemisphere

Gonyaulacysta dentata is a very large and morphologically distinctive dinoflagellate cyst species which was first described from the Callovian (Middle Jurassic) strata of the Isle of Skye, northwest Scotland. The diagnosis and description of this species are emended herein in order to document the characteristic elongate pentagonal outline, the apicular structure, the bicavate cyst organisation, the prominent dorsal and lateral sutural crests which are typically denticulate, the discontinuous, low-relief midventral sutural ridges and the lack of a periarchaeopyle. Gonyaulacysta dentata is a reliable index taxon for the Late Callovian to earliest Oxfordian (Peltoceras athleta to Quenstedtoceras mariae zones) of the Boreal Realm and the Subboreal Province in the northern hemisphere. It is especially prominent in the Boreal Realm and the northern part of the Subboreal Province, and has been recorded from the Barents Sea region, arctic Canada, offshore Norway, the central and northern North Sea and northern Scotland. Typically this species represents a relatively low proportion of the overall dinoflagellate cyst assemblages. There are also reports of very rare specimens of Gonyaulacysta dentata from further south in the Northwest European Subprovince, i.e. France, Germany and Poland. It therefore appears to be a characteristic Boreal taxon, but low numbers migrated southwards into the Northwest European Subprovince due to a fall in palaeotemperatures during the Callovian-Oxfordian transition. The southwards expansion of this short-lived species parallels the southward migration of the Boreal ammonite family Cardioceratidae. There is a virtually mutually exclusive relationship between the Arctic species Gonyaulacysta dentata and the apparently warm-loving taxon Scriniodinium crystallinum during the Late Callovian to Early Oxfordian interval. This is consistent with the interpretation of Gonyaulacysta dentata as a cold water taxon

A palynological investigation of samples from the Oxford Clay Formation of the Bedford district (Sheet 203)

Samples 1 to 4 yielded variably productive palynofloras, the dinoflagellate cysts of which are characteristic of the late Callovian-early Oxfordian interval. Sample 1 is undifferentiated late Callovian-early Oxfordian, thus is deemed to be from either the Stewartby or the Weymouth members of the Oxford Clay Formation. Samples 2 and 3 are late Callovian on dinoflagellate cyst evidence, so are from the Stewartby Member of the Oxford Clay Formation. Sample 4 produced an early Oxfordian dinoflagellate cyst flora, hence is interpreted as being from the Weymouth Member of the Oxford Clay Formation. Samples 5 to 8 produced diverse dinoflagellate cyst assemblages which are characteristic of the mid Callovian Coronatum Zone. This indicates a correlation with the middle part of the Peterborough Member (Oxford Clay Formation). Because there is no variation in the ages of the palynomorphs observed, the samples are interpreted as being from in situ Peterborough Member due to their purity and also the consistent relative proportions of palynomorph

A palynological investigation of the chalk-rich diamicts of north Norfolk

Except for sample 4, the samples examined are either rich in Kimmeridgian or Late Cretaceous dinoflagellate cysts. This conclusion would support two distinct ice flow directions for this chalk-rich till facies in this area. Samples 1, 2, 3, 6 and 8 are rich in Kimmeridgian dinoflagellate cysts. They also have similar palynomorph signatures in that the Kimmeridgian dinoflagellate cyst floras are generally associated with low levels of Carboniferous and Lower Cretaceous spores and, unsurprisingly, significant levels of Jurassic miospores. Sample 8 yielded the most diverse Kimmeridgian dinoflagellate cysts that are indicative of the input of Lower Kimmeridge Clay Formation. The other Kimeridgian rich samples (1, 2, 3 and 6) are similar in species makeup, so these are also assumed to have been derived from the Lower Kimmeridge Clay. Samples 5 and 7 are dominated by Late Cretaceous dinoflagellate cysts indicative of substantial input from the Chalk Group. The association in sample 5 is indicative of the Campanian to early Maastrichtian, indicating input from the Upper Chalk. The flora from sample 7 is similar to that of sample 5 and is also assumed to have been derived from the local Upper Chalk. Sample 4 is unlike the remainder of the samples and is dominated by Quaternary pollen and non-age diagnostic forms, with lesser proportions of early Toarcian, Late Cretaceous and Palaeogene dinoflagellate cysts

A palynological study of the Gustav Group from north-west James Ross Island Antarctica

The material from station DJ.1456/DJ.1504 at Brandy Bay is from the Lewis Hill and Brandy Bay members of the Whisky Bay Formation. The presence of Ascodinium acrophorum indicates a mid Vraconian (latest Albian) to early Cenomanian age for this succession. The occurrence of Ascodinium cf. serratum, and certain semi-quantitative data are strongly suggestive of the early Cenomanian. The palynological associations from station DJ.1502 at Brandy Bay are similar to those observed from station DJ.1456/DJ.1504. The station DJ.1502 succession is entirely within the Lewis Hill Member. Key dinoflagellate cyst taxa are indicative of the Vraconian (latest Albian) to early Cenomanian interval. The consistent occurrences of Ascodinium cf. serratum strongly suggest the early Cenomanian, but this cannot be deemed to be unequivocal evidence of this substage. Semi-quantitative dinoflagellate cyst data also suggest the early Cenomanian. Twelve samples from station DJ.1504 at Brandy Bay were studied. These are from the Lewis Hill and Brandy Bay members of the Whisky Bay Formation. The six Lewis Hill Member samples proved more palynologically-rich than the six samples from the overlying Brandy Bay Member. The assemblages from the Lewis Hill Member are similar to those from this unit at station DJ.1502, however, the occurrence of unequivocal Ascodinium serratum is indicative of the early Cenomanian. This study is the first definite palynological evidence for the Cenomanian Stage in the James Ross Basin. The material from the overlying Brandy Bay Member produced the key marker species Isabelidinium acuminatum and Isabelidinium glabrum, which is indicative of the early Turonian. This conclusion is consistent with previous palynological studies, but not strontium isotope stratigraphy that invoked a late Turonian age for the underlying uppermost Lewis Hill Member. The Hidden Lake Formation of station DJ.1507 at Brandy Bay yielded dinoflagellate cysts such as Conosphaeridium striatoconus and Spinidinium echinoideum subsp. rhombicum, which indicate a Coniacian age. This finding is in accord with previous studies

A palynological investigation of the glaciogenic sediments of Clipsham Quarry, Rutland

Jurassic palynomorphs dominate samples 1, 3-6 and 10; these are virtually all of Callovian-Oxfordian age. Some minor evidence of Carboniferous and Toarcian reworking was also observed. Exclusively Callovian and Oxfordian index species are common, and forms that are indicative of the late Callovian-early Oxfordian interval are especially abundant. This indicates the incorporation of significant levels of the Oxford Clay Formation. Smaller levels of recycling from the Cornbrash and Kellaways formations are also present. These lithostratigraphical assessments indicate that this Jurassic input was local, and probably derived from the Spalding-Sleaford area of south Lincolnshire to the north-east. Sample 2 yielded a sparse palynoflora, indicating some input from probable marine Quaternary sediments; no evidence of the reworking of Palaeozoic or Mesozoic strata is present. Sample 7 produced a sparse palynoflora indicating input from Carboniferous, Jurassic/?Cretaceous and probable terrestrial Quaternary strata. Sample 8 comprises isolated chalk pebbles from a chalky till and produced a sparse palynoflora. No stratigraphically diagnostic taxa were encountered. The sparseness of the dinoflagellate cyst associations indicates that the Chalk in this sample is not from the Upper Chalk. Sample 9 produced an abundant palynoflora that is dominated by Jurassic miospores; no marine Jurassic microplankton were observed. Low numbers of ?Rugospora spp., a Lower Carboniferous spore, and indeterminate dinoflagellate cysts were also observed. The presence of forms such as Leptolepidites spp. and Neoraistrickia gristhorpensis indicates that this sample was derived from Middle Jurassic strata deposited in a terrestrial/freshwater regime. The source is most likely to be the Rutland Formation, a Bathonian heterolithic, rhythmic unit. The Rutland Formation outcrop is local to Clipsham Quarry. Sample 9 is significantly different to samples 1, 3-6 and 10, which are characterised by younger Jurassic material

A palynological study of the glacigenic sediments of the Aberdeen/Buchan area

The thirteen samples produced variably productive organic residues and palynofloras. Typically, the samples include relatively low numbers of Carboniferous spores, abundant Mid-Late Jurassic miospores, moderate to low levels of Late Jurassic, principally Kimmeridgian, dinoflagellate cysts, extremely low levels of Early Cretaceous palynomorphs, variable levels of Cretaceous/Palaeogene-Neogene dinoflagellate cysts and some Quaternary pollen and spores. The bulk of the Carboniferous spores are most likely to have been derived from Westphalian strata. The vast majority of Jurassic dinoflagellate cysts are indicative of the Kimmeridge Clay Formation and typically each productive sample contains both early and late Kimmeridgian marker species. The Carboniferous, Jurassic and Cretaceous palynomorphs are probably derived from the Moray Firth Basin. Sample 4 from the Bellscamphie Railway Cutting Excavations yielded a highly unusual palynoflora, which is dominated by spores of Lower Carboniferous (Tournaisian-Viséan) aspect. Sample 10 from Camp Fauld, south-west of Peterhead, included definite Westphalian spore taxa. Sample 9 from Bearnie, Buchan produced low numbers of Callovian/Oxfordian dinoflagellate cysts. The presence of late Hauterivian-early Barremian markers in sample 8 at the Moss of Cruden excavations, south-west of Peterhead was not confirmed. Sample 7 from the Teuchan Clay Pit, north-east of Hatton produced an assemblage wholly comprising Quaternary pollen and spores. No derived Carboniferous, Jurassic, Cretaceous or Palaeogene/Neogene palynomorphs were observed. The dominance of spore taxa with minor herbaceous pollen indicates a damp, upland region with a moorland/heathland vegetation; this is probably the local pollen component

A palynological investigation of two samples of the Thrussington Till from the Leicester district

Sample 1 proved extremely organically-productive; the palynoflora comprises Carboniferous, Triassic, Jurassic and Quaternary forms. Upper Carboniferous (Westphalian) miosopores are the most prominent element (40.9%), thereby indicating reworking of significant levels of Coal Measures into the Thrussington Till south of Leicester city centre. The most likely source of these Carboniferous spores is the Pennines to the north. Late Triassic (Rhaetian) palynomorphs are also present in moderate proportions (5.9%). The most likely lithostratigraphical units which provided this Rhaetian input are the Westbury and/or Lilstock formations from the local area. Jurassic palynomorphs are relatively prominent (27.1%). These are dominated by miospores that comprise 26.4% of the entire flora. The presence of key markers indicates input from Toarcian and Mid-Late Jurassic strata. It is possible that many of these miospores were derived from the several paralic deposits of the Middle Jurassic succession of the East Midlands Shelf to the north-east. Jurassic dinoflagellate cysts are, by contrast, rare (0.7%) and indicate input from the late Callovian to early Oxfordian Stewartby and/or Weymouth members of the Oxford Clay Formation from the outcrop north-east of Leicester. Low levels (1.3%) of Quaternary pollen grains of aspect were observed and these are assumed to have been derived locally. Forms that are stratigraphically non-diagnostic are present in significant proportions (24.8%), and no evidence of input from the Lower Palaeozoic, Devonian, Permian or Cretaceous-Neogene was observed. Sample 2 also yielded an abundant and well-preserved palynoflora that is entirely comprised of Westphalian (Upper Carboniferous) miospores. This means that large levels of Coal Measures were incorporated into the Thrussington Till at Braunstone. It is highly unusual to encounter a till which is characterised by a non-heterogenous assemblage. The source of these spores is most likely to be the Pennines. The absence of Late Triassic forms in this sample is interesting because other Thrussington Till samples have yielded Rhaetian palynomorphs. The Westphalian miospores represent the far-travelled component; whereas the Rhaetian palynomorphs are locally-derived. It is possible, for example, that the local component diluted the far-travelled component dependent on the availability of Rhaetian strata in the path of the glacier. A detailed study of a complete section of the Thrussington Till would be required in order to fully assess the organic heterogeneity of this unit

Subdivision of the dinoflagellate cyst Family Suessiaceae and discussion of its evolution

Abstract. The recent description of Umbriadinium mediterraneense Bucefalo Palliani & Riding 1997 from the Early Jurassic of central Italy and Greece has provided new information on the phylogeny of the dinoflagellate cyst Family Suessiaceae. On the basis of the morphology of the five suessiacean genera, a subdivision of the family into two new subfamilies is proposed. These are the Late Triassic Suessioideae and the Early Jurassic Umbriadinoideae. The evolution of the Family Suessiaceae is related to the evolution of scleractinian corals, largely on the basis of the similarity of their evolutionary patterns and geographical palaeodistributions

Palynology of Faroe-Shetland Basin well 206/05-1 between 3155.08 and 3901.90 m

As part of Phase 3 of the BGS Faroe-Shetland Consortium project on the Jurassic of the UK sector of the Faroe-Shetland Basin, detailed logging of core from well 206/05-1 was undertaken. Nine core samples were taken for palynology between 3155.08 and 3901.90 m in order to provide age determinations and additional facies information. Samples 1 to 6 (3155.08 to 3269.07 m), yielded sparse palynomorph floras including the dinoflagellate cyst Ambonosphaera staffinensis in sample 6 (3269.07 m). This occurrence indicates a Late Jurassic, probably Mid Oxfordian to Mid Volgian, age. The palynologically productive interval between 3155.08 and 3269.07 m represents marine deposition. The interval between 3272.08 and 3901.90 m (samples 7 to 9) proved entirely barren, and cannot be dated