Dinoflagellate Cyst Assemblages in Surface Sediments from Three Shallow Mediterranean Lagoons (Sardinia,North Western Mediterranean Sea)

The present study identified and quantified dinoflagellate cysts in surface sediments from three Mediterranean lagoons. Sediment samples were recovered from 11 stations in May 2009 at Cabras Lagoon, eight stations in May 2010 at Corru S'Ittiri Lagoon, and five stations in May 2011 at Santa Giusta Lagoon. Fifty-three dinoflagellate cyst morphotypes were identified. Sixteen species are first reports for the lagoons, and two for the Mediterranean Sea. Moreover, a new Scrippsiella species was discovered in Cabras. Seven harmful algal species were identified, primarily belonging to the potentially toxic genus Alexandrium. Total cyst abundance, number of morphotypes, and assemblages varied among lagoons, and each lagoon showed a distinct morphotype composition. A degree of heterogeneity was also detected within lagoon. Cabras and Santa Giusta cyst assemblages were characterised by morphotypes belonging to the autotrophic genus Scrippsiella, whereas Corru S'Ittiri assemblages showed dominance of heterotrophic morphotypes, including Protoperidinium cf tricingulatum. Differentiation among lagoons was also evident according to environmental conditions. Salinity proved to be a fundamental variable in determining total cyst abundance, morphotype number, and composition. This study was among the first to examine dinoflagellate cyst composition in coastal lagoons, especially from the Mediterranean region, and contributed data that increased our knowledge of cyst-producing dinoflagellates in these environments.     

Surface salinity and nutrient variations during the Littorina Stage in the Fårö Deep,Baltic Sea

Early to late Holocene sediments from core F80, Fårö Deep, Baltic Sea, are investigated for their palynomorph composition and dinoflagellate cyst record to map variations in sea‐surface‐water salinity and palaeoproductivity during the past 6000 years. The F80 palynomorph assemblages are subdivided into four Assemblage Zones (AZs) named A to D. The transition from the stratigraphically oldest AZ A to B reflects a marked increase in palaeoproductivity and a gradual increase in surface‐water salinity over the ～1500 years between the Initial Littorina (former Mastogloia Sea Stage) and Littorina Sea Stage. A period with maximum sea‐surface salinity is recorded within the overlying AZ C from 7200 to 5200 cal. a BP, where the process length of Operculodinium centrocarpum indicates that average salinities were probably the highest (～15–17 versus 7.5 psu today) since the last glaciation. The change from AZ C to D correlates with a shift from laminated to non‐laminated sediments, and the dinoflagellate cyst assemblages suggest that the surface‐ and the deep‐water environment altered from c. 5250 cal. a BP, with less productivity in the surface water and more oxygenated conditions in the deep water. Here we demonstrate that past regional changes in surface salinity, primary productivity and deep‐water oxygenation status in the Baltic Sea can be traced by mapping overall palynomorph composition, dinoflagellate cyst assemblages and variations in the process length of O. centrocarpum in relation to periods of laminated/non‐laminated sedimentation and proportion of organic‐matter in the sediments. An understanding of past productivity changes is particularly important to better understand present‐day environmental changes within the Baltic Sea region.     

Palynological and geochemical response to environmental changes in the Lower Cretaceous in the Outer Western Carpathians; a record from the Silesian unit, Czech Republic

Rich dinoflagellate cyst assemblages recorded from the Vendryne Formation, Tesin Limestone, and Hradiste Formation of the Silesian unit, Czech Republic are presented. The results of a qualitative and quantitative study of dinoflagellate cysts are presented and discussed. Age-assessment of the sediments based on 86 species suggests a Late Tithonian to Early Berriasian age for the Vendryne Formation and a Late Berriasian (Otopeta Ammonite Zone) to the basal part of the Late Valanginian (Verrucosum Ammonite Zone) age for the Tesin Limestone. Pelitic flyschoid sediments of the Hradiste Formation belong to the Late Valanginian - Early Hauterivian age. Quantitative palynological study and carbon isotope analysis were applied to understand the change from the grey clays to dark grey clays sedimentation. The dinoflagellate cyst assemblages show deposition in a shallow-sea environment. An increasing amount of sporomorphs towards the overlying layers (they are the most abundant in the Hradiste Formation) shows a growing supply of terrestrial material at the same time. The values of δ¹³C increased significantly from a level of 0.43 or 0.75-1.81‰ in the Late Valanginian. This change probably indicates an increase in organic matter storage and perturbation of the carbon cycle connected with the dark grey clays sedimentation.     

Dinoflagellate Cysts in Surface Sediments from Southern Coast of Korea

To investigate the distributions of dinoflagellate cysts in relation to environmental conditions from southern coast of Korea, surface sediment samples collected from 11 stations in Gamak Bay, Yeoja Bay and the offshore area of Yeoja Bay were analyzed. Dinoflagellate cyst assemblages observed in the study area included many species commonly reported from other temperate regions. Among them, Polykrikos cysts were dominant, together with Brigantedinium spp. and Spiniferites spp. Based on cluster analysis, dinoflagellate cyst assemblages were divided into two main groups; group I, located in Yeoja Bay and group II, located in Gamak Bay and the offshore area of Yeoja Bay. Principal component analysis identified differences in salinity levels as the main environmental factors affecting the distributional characteristics of dinoflagellate cyst assemblages in the study area. Gamak Bay is a typical eutrophied area as result of extensive human activities around the bay, and heterotrophic cysts, including Polykrikos cysts, are remarkably abundant and likely to be a useful indicator for eutrophication in Gamak Bay.     

Norwegian sea‐surface palaeoenvironments of marine oxygen‐isotope stage 3: the paradoxical response of dinoflagellate cysts

High‐resolution marine palynological data have been obtained from two very long sediment cores (MD952009 and MD952010) retrieved from the southern Norwegian Sea. The dinoflagellate cyst assemblages show pronounced fluctuations in composition, which correlate strongly with magnetic susceptibility records and also mimic the δ¹⁸O signal of the GISP2 Greenland ice‐core. If focusing on the period from 48 to 30 cal. kyr BP, this correlation suggests a paradoxical response of the sea‐surface environments to the atmospheric conditions over Greenland: when the Greenland δ¹⁸O signal reflects warm interstadial conditions, the Norwegian Sea depicts cold sea‐surface temperatures with quasi‐perennial sea‐ice cover (based on dinoflagellate cysts). In contrast, when the Greenland δ¹⁸O records cold stadial periods, the Norwegian Sea‐surface temperatures are warm (based on dinoflagellate cysts), probably linked to inflow of the North Atlantic Drift. These results, similar in both cores, are contrary to those of previous studies and shed light on a possible decoupling of Norwegian sea surface‐water conditions and atmospheric conditions over Greenland. This decoupling could be linked to an atmosphere–ocean system behaving similar to that which the Northern Hemisphere is experiencing at present, i.e. strongly variable owing to the North Atlantic Oscillation. Copyright © 2002 John Wiley & Sons, Ltd.     

The Early Pleistocene Praetiglian and Ludhamian pollen stages in the North Sea Basin and their relationship to the marine isotope record

In this paper, the currently accepted correlation of the Early Pleistocene Ludhamian stage of England with the Tiglian‐A sub‐stage of the Netherlands is challenged. Recent investigations of Early Pleistocene marine North Sea deposits from a borehole near Noordwijk (the Netherlands) yielded evidence from molluscs, dinoflagellate cysts and sporomorphs for an alternation of warm‐temperate and arctic intervals within the Praetiglian and Tiglian stages. Marine equivalents of the terrestrial‐based pollen sub‐stages Tiglian A and B have been recognised in the upper part of the sequence. A Praetiglian age can be assigned to the lower part of the sequence on the basis of mollusc analysis. Within the Praetiglian, an alternation of warm and cold phases has been recognised from both the dinoflagellate cyst and molluscan records. Three cold phases within the Praetiglian are tentatively correlated with marine isotope stages (MIS) 96–100. The molluscan assemblages provide evidence for climate forcing of the sea level: highest sea levels are reached in the warm‐temperate intervals. Within the Praetiglian, an interval with an acme zone of the dinoflagellate cyst Impagidinium multiplexum, is correlated with the Ludhamian and tentatively linked to MIS 97 and/or MIS 96. The cold molluscan assemblages from the Noordwijk borehole include an acme zone of Megayoldia thraciaeformis, the first and only occurrence of this North Pacific bivalve in the North Sea Basin. Copyright © 2006 John Wiley & Sons, Ltd.     

The Pleistocene palaeoenvironment and stratigraphy of Flatey island (northern Iceland): a preliminary assessment based on palynomorphs

For the first time, palynological data (pollen, spores and dinoflagellate cysts) from Pleistocene outcrop and core deposits from Flatey, off northern Iceland, are presented. The study provides a reconnaissance stratigraphical assessment of the deposits, the correlation between the Pleistocene of Flatey and the well‐known Tjörnes section on the mainland, and the reconstruction of the Pleistocene palaeoenvironment. The preservation of the assemblages is poor to moderate, whereas the diversity and richness are moderate to high. The pollen and spores indicate vegetation composed mainly of sedges and heath, comparable to the vegetation in the Tjörnes area during deposition of the Pleistocene Breidavík Group. Analysis of dinoflagellate cyst assemblages from an outcrop sample allowed their assignment to the Lower Pleistocene dinoflagellate cyst zone DAZ5, previously defined in the Tjörnes section. A core sample yielded a dinoflagellate cyst assemblage unknown from the Tjörnes area. The dinoflagellate cyst data combined with the palaeomagnetic record, the radiometric dating of lavas, and the position of the diamictites and tuff layers allowed refinement of the previously proposed stratigraphical correlations between the Tjörnes area and the Flatey core. The deposition of the sequence from the Flatey core took place during the Matuyama, i.e. between 2.59 and 0.78 Ma, and several hiatuses are postulated. The Lower Pleistocene dinoflagellate cyst assemblages from the outcrop sample bear similarities to those recovered from fully marine subsurface samples on the northern shelf of Iceland within the Polar Front realm. Similar oceanographical conditions influenced by the Irminger Current and the East Icelandic Current can be inferred for Early Pleistocene times.     

Dinoflagellate Cysts in Coastal Sediments as Indicators of Eutrophication: A Case of Gwangyang Bay,South Sea of Korea

Diatom densities in the surface water and dinoflagellate cysts in bottom sediments of Gwangyang Bay were studied to determine changes in the phytoplankton community structure in response to anthropogenic eutrophication and to assess the use of dinoflagellate cysts as indicators of coastal eutrophication. Our results show that, in nutrient-enriched environments, diatoms are particularly benefited from the nutrients supplied and, as a consequence, heterotrophic dinoflagellates that feed on the diatoms can be more abundant than autotrophic dinoflagellates. In short-core sediment records, a marked shift in autotrophic–heterotrophic dinoflagellate cyst compositions occurred at a depth of approximately 9–10 cm corresponding to the timing of the 1970s industrialization around Gwangyang Bay. This tentatively indicates that diatom and dinoflagellate communities here have undergone a considerable change mainly due to increased nutrient loadings from both domestic sewage effluent and industrial pollution. Our study suggests a possible potential use of dinoflagellate cysts in providing retrospective information on the long-term effects of coastal eutrophication.     

Correlation and paleoenvironments of middle Paleogene marine beds based on dinoflagellate cysts in southwestern Patagonia,Argentina

An understanding of paleonvironmental and paleoceanographic evolution of the Southwestern Atlantic Ocean during the Palaeogene is prevented by the lack of precise tools to date and correlate the sedimentary units. Palynological samples collected in the upper portion of the Man Aike Formation, which crops out southern Lago Argentino area, in the southwest of the Austral Basin (50°21′45″S–72°14′30″W), contain well preserved marine organic dinoflagellate cysts, which are potentially important biostratigraphic and paleoenvironmental indicators. Herein we describe the composition of the Man Aike Formation's dinoflagellate cyst assemblages and compare them to similar assemblages collected in the same basin in the upper member of the Río Turbio Formation using Compositional Statistical Analysis. The dinoflagellate cyst assemblages from the upper part of the Man Aike Formation are highly correlated to the assemblages from the upper member of the Río Turbio Formation from outcropping sections (51°31′13″S–72°15′11″W) and with the lower part of sediment cores drilled by Yacimientos Carboníferos Fiscales in the Río Turbio Formation area. These dinoflagellate cyst assemblages show a very low correlation with the assemblages from the upper part of the Yacimientos Carboníferos Fiscales's cores. The comparison of our results with the high-resolution Southern Pacific Ocean dinoflagellate cyst zonation for the late Palaeocene to late Eocene allow us to date some of the dinoflagellate events recorded in formations of southwestern Patagonia. The assemblages from the Man Aike Formation and the lower part of the upper member of the Río Turbio Formation relate to the zones SPDZ11 and SPDZ12 and are assigned to the mid-middle Eocene (late Lutetian to early Bartonian). The biostratigraphy proposed herein constrains the age of the Man Aike Formation and equivalent units based on calcareous microfossil data, mollusks affinities and ⁸⁷Sr/⁸⁶Sr isotopic values to an age ranging between ∼42 and 39 Ma. The assemblages from the upper part of the upper member of the Río Turbio Formation relate to the SPDZ13 Zone, which corresponds to the late Eocene (early Priabonian). The dinoflagellate cyst assemblages indicate that they were under the influence of relatively warm, marine open waters in an inner-shelf environment for the lower part of the sections. In the upper part of the sections, the assemblages suggest shallow marine waters associated with coastal areas and high trophic levels, possibly as a result of freshwater inputs.     

Dinoflagellate cyst biostratigraphy of the Upper Miocene Deurne Sands (Diest Formation) of northern Belgium,southern North Sea Basin

Diverse and well‐preserved palynomorph assemblages recovered from the Deurne Sands, a local member of the Upper Miocene Diest Formation near Antwerp, allow the recognition of dinoflagellate cyst biozones defined in the North Atlantic realm (East Coast, USA) and the North Sea region (Nieder Ochtenhausen well, northern Germany). Based on the dinoflagellate cyst assemblages and the calcareous microfossils, the deposition of the Deurne Sands took place at some time during middle to late Tortonian (Late Miocene). These sands can be correlated biostratigraphically with the Dessel Sands in the Campine area of northern Belgium. This correlation demonstrates the existence of two separate and contemporary depositional areas in northern Belgium during early Late Miocene times. Copyright © 2002 John Wiley & Sons, Ltd.     

A dinoflagellate cyst record of Holocene climate and hydrological changes along the southeastern Swedish Baltic coast

A high-resolution, well-dated dinoflagellate cyst record from a lagoon of the southeastern Swedish Baltic Sea reveals climate and hydrological changes during the Holocene. Marine dinoflagellate cysts occurred initially at about 8600 cal yr BP, indicating the onset of the Littorina transgression in the southeastern Swedish lowland associated with global sea level rise, and thus the opening of the Danish straits. Both the species diversity and the total accumulation rates of dinoflagellate cysts continued to increase by 7000 cal yr BP and then decreased progressively. This pattern reveals the first-order change in local sea level as a function of ice-volume-equivalent sea level rise versus isostatic land uplift. Superimposed upon this local sea level trend, well-defined fluctuations of the total accumulation rates of dinoflagellate cysts occurred on quasi-1000- and 500-yr frequency bands particularly between 7500 and 4000 cal yr BP, when the connection between the Baltic basin and the North Atlantic was broader. A close correlation of the total accumulation rates of dinoflagellate cysts with GISP2 ice core sea-salt ions suggests that fluctuations of Baltic surface conditions during the middle Holocene might have been regulated by quasi-periodic variations of the prevailing southwesterly winds, most likely through a system similar to the dipole oscillation of the modern North Atlantic atmosphere.     

Last Interglacial marine environments in the White Sea region, northwestern Russia

Marine sediments from river sections in the Mezen River drainage, northwest Russia, have been analysed for dinoflagellate cysts, foraminifers and molluscs. The sediments were dated by pollen analysis and by reference to the local sea-level history, and are Late Saalian to late Eemian (c. 133 to 119.5 kyr in age). The Late Saalian deglaciation was characterized by Arctic conditions, but a few centuries into the Eemian the Gulf Stream system carried warm Atlantic water into the region. At 129.8 kyr BP there was a marked increase in the influx of Atlantic water, and the advection of warm Atlantic water was stronger and probably penetrated further eastwards than at present. The molluscs, dinoflagellate cysts and foraminifers reflect conditions warmer than present and that the optimum temperature occurred at the time of the early Eemian global sea-level rise. Around 128 kyr BP, the eustatic sea-level rise was curbed by isostatic rebound and accompanying regression and constriction of marine passages to the White Sea. Local, low-saline, stratified basins developed and characterized the next five to six millennia.     

Dinoflagellate cysts from the Upper Bajocian–Lower Oxfordian of the Dalichai Formation in Binalud Mountains (NE Iran): their biostratigraphical and biogeographical significance

The Binalud Mountains of NE Iran represent the easternmost extension of the Alborz Range. After the Mid-Cimmerian orogenic event and rapid subsidence, the deep marine sediments of the Dalichai Formation were deposited. A well-preserved section of the formation was sampled for palynological purposes. The study revealed diverse and nearly well-preserved dinoflagellate cyst assemblages. Thirty-six dinoflagellate cyst species identified lead to identification of four biozones: Cribroperidinium crispum (Late Bajocian), Dichadogonyaulax sellwoodii (Bathonian to Early Callovian), Ctenidodinium continuum (Early to Late Callovian), and Ctenidodinium tenellum (Early Oxfordian) biozones. The close similarities of dinoflagellate cyst assemblages between Binalud Mountains, NE Iran, with those of Alborz Mountains (Northern Iran) during Middle Jurassic confirm the connection between two sedimentary basins during this time in Iran. Meanwhile, this biozonation corresponds largely to that established in Northwest Europe and reveals the marine connection between NE and North of Iran with Northwest Europe and the Northwestern Tethys during the Late Bajocian to Early Oxfordian.     

Constraining Holocene sea‐surface conditions in the south‐western Black Sea using dinoflagellate cysts

This paper presents two dinoflagellate cyst records from the south‐western shelf of the Black Sea. A new site, MAR05‐13, from the Sakarya shelf is described and placed into context with site MAR02‐45, ～250 km distant on the Thracian shelf. The records provide a centennial resolution of surface water conditions in the Holocene. Analysis of the data suggests that the surface salinity of the south‐western shelf increased in a gradual and progressive manner. In the period ～11 000–9000 cal a BP the assemblages suggest surface‐water salinities between 7–13 psu. The initial arrival of euryhaline species, ～8100 cal a BP, is linked to the reconnection of the Black Sea and Marmara Sea. The suggested surface water changes related to the reconnection took approximately 1000 years. Following this initial change in assemblages, a further increase in the number of euryhaline species is noted between 5000 and 4000 cal a BP. This is linked to the establishment of more saline surface‐water conditions, close to present‐day values. The record for MAR05‐13 highlights the complexity of the changes in cyst assemblages during the mid‐Holocene. Copyright © 2012 John Wiley & Sons, Ltd.     

Plankton in the Norwegian-Greenland Sea: from living communities to sediment assemblages —an actualistic approach

A synoptic study is carried out to reconstruct the development of the plankton community in the late Quaternary in the Norwegian-Greenland Sea. It comprises quantitative analyses of coccolithophores, dinoflagellate cysts, diatoms and radiolarians. An actualistic approach is applied to evaluate the different fossil records of these plankton groups. The preliminary results of the current investigation are reported here.The composition and distribution of living communities of coccolithophores are presented as an example. A close relationship between the distribution of regional groups and surface water masses is observed. Seasonal vertical fluxes of coccolithophores and radiolarians through the water column show similar patterns within different years. However, diatoms are highly variable, both in absolute fluxes and species composition. The differentiation of sporadic and periodic processes is evident only after several years of observation. During settling and sedimentation biotic and abiotic processes such as grazing, dissolution and lateral transport alter the assemblages.Investigation of death assemblages in surface sediments reveals that in spite of these alteration processes the abundance and species distribution are related to surface water masses. Higher abundances and diversities are usually found in sediments underlying the warm Norwegian Current. Concentrations decrease to the north-west towards the cold polar water masses.The sediment assemblages of all groups are strongly altered relicts of former living communities. They are characterized by distinct changes in species composition and absolute abundances related to palaeo-oceanographic development. Their variation through the sedimentary record is used to distinguish four ecostratigraphic units during the late Weichselian and Holocene.     

The palynology and geology of the Lower Cretaceous (Aptian–Albian) of Munday’s Hill Quarry,Bedfordshire, UK

Early Cretaceous sediments of Aptian–Albian age outcrop at Munday’s Hill Quarry, Bedfordshire, England. Previous papers describing the section have resulted in different terminologies being applied. The Lower Cretaceous in Bedfordshire is represented by sediments belonging to the Lower Greensand Group and the Gault Clay Formation. Within the Lower Greensand Group in the study area the Woburn Sands Formation, are of Aptian–Albian age. Selected samples have been analysed for palynology. The analysis reveals diverse palynomorph assemblages, including well-preserved dinoflagellate cysts and sporomorphs. Comparison of the assemblages with published records indicates that the lower samples are of Late Aptian age. Forms recorded include common Kiokansium unituberculatum, Cerbia tabulata, Aptea polymorpha and Cyclonephelium inconspicuum. An Early Albian age is indicated for the uppermost sample.     

Palynostratigraphy of Oligocene-Miocene continental deposits in Southwestern Siberia

Data on spores, pollen, and dinoflagellate cysts studied in composite section of Oligocene-Miocene deposits in southern part of West Siberia are presented. Eleven biostratigraphic units distinguished in the section are ranked as palynozones and beds with palynological assemblages. Palynological data substantiate age of deposits and specify ranges and boundaries of palynozones. Based on dinocyst assemblages first studied in sediments of the Zhuravka and Abrosimovo horizons (upper Oligocene, lower Miocene), the Pseudokomewuia Beds are included into local stratigraphic scheme. According to results of comparative analysis, similar and distinctive features of Oligocene-Miocene dinocyst assemblages from West Siberia, China and North America are elucidated. Based on palynological data, the local stratigraphic scheme of higher resolution is suggested for subdivision of Oligocene and Miocene deposits in southern part of West Siberia (Baraba and Kulunda lithofacies regions).     

Spatial and Temporal Variations in <Emphasis Type="Italic">Pyrodinium bahamense</Emphasis> Cyst Concentrations in the Sediments of Bioluminescent Mangrove Lagoon,St. Croix,USVI

Mangrove Lagoon, located on the island of St. Croix, US Virgin Islands (USVI), is one of few actively bioluminescent lagoons in a location experiencing significant anthropogenic impacts. The bioluminescence is due to an abundance of the dinoflagellate Pyrodinium bahamense in the water column. We recovered surface sediments and sediment cores from Mangrove Lagoon to analyze the spatial distribution and temporal variability of P. bahamense cysts in this system. Surface sediment P. bahamense cyst concentrations ranged from 0 to 466 cysts g^?1 dry sediment, with higher abundances associated with elevated surface water nutrient concentrations and a mixed terrestrial–marine organic matter source regime. In combination with available bioassay data, we hypothesize that phytoplankton utilize nutrients rapidly and subsequent decay of organic matter makes nutrients available for dinoflagellates at the sediment–water interface in the eastern and northern quadrants of the lagoon. However, the nutrients are rapidly exhausted during counterclockwise lagoon circulation resulting in the decline of primary productivity and dinoflagellate abundance in the western quadrants. Downcore profiles suggest that P. bahamense blooms have been occurring for decades, declining in recent years. No cysts were present in sediments predating dredging activities of the 1960s that created Mangrove Lagoon. Recent reductions in cyst abundance may be the result of limited primary productivity caused by restricted water exchange with Salt River Bay due to shallowing of a sill at the mouth of the lagoon. This research highlights the need for more comprehensive geochemical and fossil analyses to better understand long-term ecological variability and inform conservation efforts of these unique habitats.     

Biostratigraphy of Eemian sediments at Mertuanoja, Pohjanmaa (Ostrobothnia), western Finland

The till-covered clay and silt deposits at Mertuanoja, Pohjanmaa (Ostrobothnia), western Finland, have been investigated in great detail. The Eemian interglacial environment is reconstructed here on the basis of pollen, diatom and dinoflagellate analyses. The pollen stratigraphy shows an interglacial vegetational succession reflecting stable climatic conditions typical of the Eemian Stage in the Pohjanmaa area. The initial Betula forests were followed by Pinus-Betula forests with Quercus. The next successional phase was dominated by Betula, Pinus and Alnus; temperate deciduous trees and Corylus also grew in the area. Later, Picea advanced and temperate deciduous trees declined. Some Corylus was, however, still present and thermophilous Osmunda thrived in wet places. The diatom record indicates that the sediments were deposited first in a freshwater basin, then in the Eemian Baltic Sea, and finally in a freshwater basin once more. The presence of dinoflagellates demonstrates that the Eemian Baltic Sea, when at its maximum extent, was connected to the Atlantic Ocean, which brought northern cool-temperate surface waters to Finland as far north as Mertuanoja. Mertuanoja is the first interglacial site at which numerous dinoflagellate cysts were encountered in Finnish Quaternary sediments.     

Aptian to Coniacian (Early–Late Cretaceous) palynostratigraphy of the Gustav Group, James Ross Basin, Antarctica

The Gustav Group of the James Ross Basin, Antarctic Peninsula, forms part of a major Southern Hemisphere Cretaceous reference section. Palynological data, chiefly from dinoflagellate cysts, integrated with macrofaunal evidence and strontium isotope stratigraphy, indicate that the Gustav Group, which is approximately 2.6 km thick, is Aptian–Coniacian in age. Aptian–Coniacian palynofloras in the James Ross Basin closely resemble coeval associations from Australia and New Zealand, and Australian palynological zonation schemes are applicable to the Gustav Group. The lowermost units, the coeval Pedersen and Lagrelius Point formations, have both yielded early Aptian dinoflagellate cysts. Because the overlying Kotick Point Formation is of early to mid Albian age, the Aptian/Albian boundary is placed, questionably, at the Lagrelius Point Formation–Kotick Point Formation boundary on James Ross Island, and this transition may be unconformable. Although the Kotick Point Formation is largely early Albian on dinoflagellate cyst evidence, the uppermost part of the formation appears to be of mid Albian age. This differentiation of the early and mid Albian has refined the age of the formation, previously considered to be Aptian–Albian, based on macrofaunal evidence. The Whisky Bay Formation is of late Albian to latest Turonian age on dinoflagellate cyst evidence and this supports the macrofaunal ages. Late Albian palynofloras have been recorded from the Gin Cove, lower Tumbledown Cliffs, Bibby Point and the lower–middle Lewis Hill members. However, the Cenomanian age of the upper Tumbledown Cliffs and Rum Cove members, based on molluscan evidence, is not supported by the dinoflagellate cyst floras and further work is required on this succession. The uppermost part of the Whisky Bay Formation in north-west James Ross Island is of mid to late Turonian age and this is confirmed by strontium isotope stratigraphy. The uppermost unit, the Hidden Lake Formation, is Coniacian in age on both palaeontological and strontium isotope evidence. The uppermost part of the formation appears to be early Santonian based on dinoflagellate cysts, but strontium isotope stratigraphy constrains this as being no younger than late Coniacian. This refined palynostratigraphy greatly improves the potential of the James Ross Basin as a major Cretaceous Southern Hemisphere reference section.