Palynological Samples Research Articles

Recognition of Evamy Et Al P-Zones in the Tertiary Sediments of F- Well, Niger Delta

Palynological evaluation of Tertiary sediments in F- Well, Niger Delta Basin was carried out using Fifty (50) Ditch Cutting samples from a well at different intervals between 2,010ft and 10,170ft. The samples were prepared using standard palynological sample processing technique and analyzed under the microscope. They were about twenty three (23) diagnostic palynomorphs recognized. The evaluation of these palynomorphs species enabled us to recognize the zones. The presence of diagnostic palynomorphs such as Praedapollis africanus, Peregrinipollis nigericus, Retibrevitricolporites obodoensis and Cicatrisosporites dorogenesis aided in the establishment of the age and P-zones. The recognized P-zones are P560, P580 and P620 zones. P 560 zone was defined at depth 9,585ft to 9,960ft with increase Retibrevitricolporites oboendensis and the Quantitative Base of Peregrinipollis nigericus P 580 zone was defined at depth 9,585ft to 7,830ft with Quantitative Base of Peregrinipollis nigericus and Top of Cicatrisosporites dorogenesis and P620zone was defined at depth 7,830ft to 6,690ft with Top Praedapolis africanus and Top Cicatrisosporites dorogenesis. Palynological events and zones gotten from the studied sedimentary succession suggest Oligocene – Early Miocene Age, with numerical value of 32.7 – 22.3 Ma when aligned with the Niger Delta Chronostratigraphic Chart.Keywords: Palynology, First Downhole Occurrence, Last Downhole Occurrence, P-zones

Aptian marine ingression in the Araripe Basin: Implications for paleogeographic reconstruction and evaporite accumulation

Abstract Integrated sedimentologic and palynological analysis of four outcrops in the Aptian succession of the Araripe Basin provides information on the earliest marine connection of this basin. Palynological samples revealed well-preserved palynomorphs with diverse assemblages composed of pteridophyte spores and gymnospermic pollen grains, especially Classopollis, besides phytoclasts and abundant amorphous organic matter. Microforaminiferal linings were retrieved from two samples, both from the Santana Formation, immediately underlying the “Ipubi Layers”. The few specimens recognized are well preserved, very similar to each other in size and shape (trochospiral morphology), and usually embedded within amorphous organic matter. These records indicate that the lower Crato Member was deposited in a marine environment. The increasing marine influence in the Araripe Basin, coupled with increasing aridity, allowed the accumulation of evaporites (“Ipubi Layers”) in restrict portions of the basin. The small size of the inferred marine connection is probably why it has been so difficult to identify its precise geographic location.

Microforaminiferal linings as proxies for paleosalinity and pollution: Danube Delta example

Acid-resistant, chitin-like organic linings of foraminiferal tests in palynological assemblages are commonly considered reliable indicators of marine transgressions despite sparse information on the relationship between the organic and inorganic skeletal components. This knowledge gap constrains reliable application in paleoecological studies. Foraminiferal lining recovery in palynological samples also varieswith the chemicals and temperature used for extraction of organic residues, and care is needed to avoid damage by hydrolysis or over-oxidation. Using samples treated onlywith cold acid, we describe the test-lining relationship for five common benthic foraminiferal species from order Rotaliida in the polluted, eutrophic, microtidal environment of the Black Sea. Papillate and granulate ornament on lining surfaces reflect the morphology of benthic foraminiferal living in the low oxygen environments of the Black Sea where pore size and frequency may be related to survival. Data from 23 surface samples from the Danube delta plain and offshore in the northwest (NW)Black Sea demonstrate the relationship between benthic foraminifera and their linings in a qualitative model characterising environments from delta plain (-1.8 m water depth) to outer shelf and continental slope (>90 m), along a surface salinity gradient from about 5 to 17 psu. Compared with microforaminiferal assemblages in high salinity deltaic and coastal environments of Atlantic and Pacific Oceans, the lining abundances of the semi-marine Danube- region sediments are relatively low but they often exceed the foraminiferal abundances at the same site.A Dissolution Index based on log (organic lining: test ratio) shows that calcite preservation is low in most of the Danube Delta sub-environments. Test and lining deformity, large pore-size, and pyritization of tests and linings appear to reflect hypoxia and eutrophication. The new data provide a baseline for paleocological studies of coastline changes in the Danube Delta region, and for better understanding of marine transgressions in Paratethyan basins.

Pollen and Spores from the Lower Cretaceous of Central Mongolia and Their Paleoclimatic Significance

The present study focuses on the Lower Cretaceous Khukhteeg Formation (Central Mongolia), which yields palynological assemblage that is used to understand the paleoclimate. Palynology samples from the Khovil opencast mine Choir-Nyalga Basin in the Central Mongolia have been analyzed for palynomorphs with SEM. The assemblage is dominated by pollen to conifers, such as Pinaceae, Podocarpaceae and Taxodiaceae, indicating the vegetation of conifer forests. The assemblage contains abundant spores Schizaeaceae, Cyatheaceae, which are generally associated with wet habitats. According to the detailed analyses, the plant community indicates that warm and humid subtropical paleoclimate controlled the study area during the Early Cretaceous.

Dinoflagellate cyst assemblages across the Oxfordian/Kimmeridgian boundary (Upper Jurassic) at Flodigarry, Staffin Bay, Isle of Skye, Scotland – a proposed GSSP for the base of the Kimmeridgian

Examination of seven ammonite-calibrated palynological samples across the Oxfordian/Kimmeridgian boundary in the Flodigarry sections at Staffin Bay, Isle of Skye, northern Scotland, has revealed dinoflagellate cyst assemblages in general terms in line with previous contributions. The sparse occurrence of Emmetrocysta sarjeantii, Perisseiasphaeridium pannosum and Senoniasphaera jurassica slightly above the proposed Oxfordian/Kimmeridgian boundary may be used as a palynological approximation of the base of the Kimmeridgian. The high abundance of tests resembling modern zygnemataceous chlorophycean alga Spirogyra in two samples above the Oxfordian/Kimmeridgian boundary horizon is probably associated with increased eutrophication and possible association with ‟green tides”. This bloom is proposed as a palynofloral proxy event for the boundary in the Flodigarry section. According to previous studies, various eutrophication events may have a correlation potential in Subboreal Europe.

Organic-walled Fossil Testate Amoebae Records (late Cretaceous–holocene) from the Neotethyan–mediterranean Region

AbstractThe significance of fossil testate amoebae having organic shells and their application for biostratigraphical and paleoecological studies are unexplored fields, although these organisms are extensively used as bioindicators in ecological studies of Recent and Holocene environments. Some taxa of fossil testate amoebae with organic (chitinous, pseudochitinous, or proteinaceous) shells were recovered in Turkey from a series of palynological samples, ranging in age from Late Cretaceous to Holocene. A total of 202 samples were processed from sediments from 11 sites representing fluvial flood-plain, lacustrine, estuarine, and peat-swamp as well as shallow and deep marine facies. Nineteen taxa of the genera Arcella, Centropyxis, Frenzelina, Microcometes, Nebela, Phryganella, Pyxidicula, and Sphenoderia were recorded from the Late Cretaceous, Lower−Middle Eocene, Lower Miocene, and Quaternary sediments. The literature on fossil organic-walled testate amoebae records was also reviewed and compared with the findings in this study.

Mikrofosylia pozapyłkowe w torfach Polesia Lubelskiego i ich wartość wskaźnikowa

<p>Artykuł stanowi pierwsze opracowanie typów mikrofosyliów pozapyłkowych (ang. non-pollen palynomorphs; NPP) występujących w próbkach palinologicznych z torfowisk Polesia Lubelskiego i stanowiących istotne bioindykatory zmian paleohydrologicznych w holocenie. Analizie na obecność NPP poddano torfy z trzech stanowisk: Płotycze, Mytycze i Durne Bagno. Oznaczono kilkanaście typów NPP wśród których występowały mikrofosylia pochodzenia zwierzęcego i grzybowego. Te same typy mikrofosyliów pozapyłkowych są powszechnie w torfowiskach Niżu Europejskiego. Większość z nich stanowią bowiem gatunki kosmopolityczne. Zidentyfikowane NPP w torfach Polesia Lubelskiego są zgodne z opisami zawartymi w międzynarodowych kluczach do oznaczania. </p>

Reinterpreting the age of the uppermost ‘Old Red Sandstone' and Early Carboniferous in Scotland

ABSTRACTIn Scotland, the base of the Ballagan Formation has traditionally been placed at the first grey mudstone within a contiguous Late Devonian to Carboniferous succession. This convention places the Devonian–Carboniferous boundary within the Old Red Sandstone (ORS) Kinnesswood Formation. The consequences of this placement are that tetrapods from the Ballagan Formation were dated as late Tournaisian in age and that the ranges of typically Devonian fish found in the Kinnesswood Formation continued into the Carboniferous. The Pease Bay specimen of the fishRemigolepisis from the Kinnesswood Formation. Comparisons with its range in Greenland, calibrated against spores, show it was Famennian in age. Detailed palynological sampling at Burnmouth from the base of the Ballagan Formation proves that the early Tournaisian spore zones (VI and HD plus Cl 1) are present. TheSchopfitesspecies that occurs through most of the succession isSchopfites delicatusrather thanSchopfites claviger. The latter species defines the late Tournaisian CM spore zone. The first spore assemblage that has been found in Upper ‘ORS' strata underlying the Ballagan Formation (Preston, Whiteadder Water), containsRetispora lepidophytaand is from the early latest Famennian LL spore zone. The spore samples are interbedded with volcaniclastic debris, which shows that the Kelso Volcanic Formation is, in part, early latest Famennian in age. These findings demonstrate that the Ballagan Formation includes most of the Tournaisian with the Devonian–Carboniferous boundary positioned close to the top of the Kinnesswood Formation. The Stage 6 calcrete at Pease Bay can be correlated to the equivalent section at Carham, showing that it represents a time gap equivalent to the latest Famennian glaciation(s). Importantly, some of the recently described Ballagan Formation tetrapods are older than previously dated and now fill the key early part of Romer's Gap.

Filamentous eukaryotic algae with a possible cladophoralean affinity from the Middle Ordovician Winneshiek Lagerstätte in Iowa, USA

Previous studies on the Darriwilian (Middle Ordovician) Konservat-Lagerstätte of the Winneshiek Shale in Iowa (USA) have reported various animal and trace fossils. A search for “small carbonaceous fossils” (SCFs) in palynological samples from the Winneshiek Shale has now led to the discovery of several different kinds of organic-walled microfossils. Here we report on a particular group of filamentous microfossils that occur abundantly throughout the exposed and subsurface successions of the Winneshiek Shale. The fossils are characterised by large, elongated cells (220–600μm in length, 60–240μm in diameter) with thin and delicate walls and occasional branching. The cells often contain dark internal bodies, most likely condensed protoplasmic remains. Together, these features identify these fossils as eukaryotic rather than cyanobacterial in origin. More specifically, the cell size, cross-walls and branching pattern are shared with forms of benthic ulvophycean green algae, a group with a long but sporadic fossil record that is otherwise restricted to Proterozoic Lagerstätten. The new specimens therefore expand the known diversity of local primary producers in the palaeoenvironment of the Winneshiek Shale, and suggest that the apparent dearth of delicate filamentous green algae in the Phanerozoic record may be, in part, an artefact of low preservation potential combined with destructive processing techniques.

Use of UV-curable acrylates gels as mounting media for palynological samples

UV-curable acrylate are used as an easy, economic and rapid mounting media (m.m.). After the palynological specimens kept in water are dehydrated with Ethanol, they can be mounted in UV-curable acrylate such as Trabasil NR2 and Acrysoft urethane acrylates. These m.m. have advantages over other m.m.: specimens are not displaced in time, they are not attacked by any organism or modified by any environmental conditions such as humidity and heat. In addition refraction index is similar to that of sporopollenin and glass.

Mesozoic phytoclast records in the Sriperumbudur (Palar Basin), Kota (Chintalapudi Sub-Basin) and Dubrajpur (Rajmahal Basin) formations, India

The studies of fossil plant cuticles in palynological samples recovered from three cored boreholes located in the Indian states of Andhra Pradesh (Kota/Gangapur Formation, Chintalapudi Sub-basin, Godavari Graben, Jurassic–Cretaceous), Tamil Nadu (Sriperumbudur Formation, Palar Basin, Upper Jurassic–lowermost Cretaceous), and Jharkhand (Dubrajpur Formation, Rajmahal Basin, Upper Jurassic–Lower Cretaceous) are presented herein. Cuticles and palynomorphs were recovered by standard palynological practices in the Gondwana Palynological Laboratory of the Birbal Sahni Institute of Palaeosciences, Lucknow, India. Fossil specimens were examined under a binocular microscope and photomicrographs were taken with a digital camera. Twenty seven morphotypes of fossil cuticles (occasionally representing stomata, trichomes and secretory structures) and other tissues (e.g., a plicate parenchyma) were recovered. The morphological analysis of cuticles and associated palynomorphs reflect the presence of different groups of plants (Bennettitales, Coniferales, Ginkgoales, Polypodiales, and Pteridospermales). In some occasions, cuticles display distinct structures (e.g., monocyclic stomata, secretory structures) that allow comparisons with some extant and fossil genera. We conclude that the study of well-preserved fossil cuticles and associated palynomorphs allow taxonomic inferences on the composition of the parent floras.

A revised stratigraphy for the Palaeocene Agatdalen flora (Nuussuaq Peninsula, western Greenland): correlating fossiliferous outcrops, macrofossils, and palynological samples from phosphoritic nodules

Abstract The Cretaceous and Palaeogene floras of western Greenland that were initially described as part of the classical work “Flora fossilis arctica” by Oswald Heer in the 19th century are currently under revision. The Nuussuaq Basin has repeatedly been investigated by geologists and marine invertebrate palaeontologists. These studies provide a modern stratigraphic framework and a basis for revisions of various Cretaceous to Eocene floras from this region, and the correlation of fossil material to stratigraphic units and formal formations. This paper is the first in a series of papers that (i) correlate macrofossil (museum) material and fossil-rich localities with the modern lithostratigraphic framework, (ii) describe new pollen, spores, and other marine/freshwater palynomorphs, and (iii) revise the macrofossil remains from the Agatdalen area (particularly the Danian Agatdal Formation). Since the work of B. Eske Koch in the 1960s and 70s, questions emerged about the correlation of plant fossiliferous outcrops and whether the so-called Agatdalen flora, referred to the Agatdal Formation, originates from a single sedimentary unit or not. In this paper, we summarise the stratigraphy of the Agatdalen area and correlate the fossil plant-bearing outcrops described by Koch to the current lithostratigraphy. We establish which plant fossils belong to the Agatdal Formation and re-assign a great number of other plant fossils to their correct formations. New palynological material is briefly described and correlated to the macrofossil localities and the Agatdal Formation. Previous accounts on the macrofossils (leaves, fruits, seeds) are briefly discussed and directions for future revisions are outlined.

Darriwilian (Middle Ordovician) worms of southern Sweden

The record of scolecodonts (polychaete jaws) from the Ordovician of Sweden is very poor. In this paper, we document a Darriwilian (Middle Ordovician) assemblage recovered from palynological samples from the “orthoceratite limestone” (Lanna and Holen limestones) of Mount Kinnekulle, Västergötland, southern Sweden. The collection of diminutive specimens forms an assemblage taxonomically composed mainly of simple placognath (mochtyellids, xanioprionids) and ctenognath (tetraprionids) taxa, whereas labidognaths (polychaetaspids) and taxa with other evolutionary grade-type apparatuses are very rare or absent. In addition, putative priapulid (penis worm) teeth were identified, possibly representing the first fossil representatives recorded in Sweden. The highest scolecodont abundance coincides with the lower to middle part of the “Täljsten” interval (lower Kunda Baltoscandian Stage). These strata are interpreted as having been formed during a marked regressional phase, suggesting that the palaeobathymetry and/or bottom substrate was optimal for polychaete colonization at that time. This new assemblage from Kinnekulle adds to the global scolecodont record in which data on Middle Ordovician and older specimens are still rudimentary but of importance for understanding early polychaete phylogeny.

Palaeoecology of syn-rift topography: A Late Jurassic footwall island on the Josephine Ridge, Central Graben, North Sea

Understanding rift topography is essential for determining source areas, sediment pathways, and the type of sediment delivered to a rift basin; factors essential for interpreting petroleum systems in ancient rifts. Here we investigate Upper Jurassic sediments from the Josephine Ridge region of the Central Graben, North Sea, by integrating geophysical, palynological, petrophysical and sedimentological datasets to analyse the palaeoenvironments of the Jade and Judy horsts, the tops of which are not preserved. Interpretation of geophysical and petrophysical data together with core descriptions shows study wells to step progressively away from the Josephine Ridge into adjacent grabens. One hundred and five palynological samples from six wells range from the Oxfordian to the Lower Tithonian, spanning the syn-rift period of the Central Graben. Samples from the adjacent grabens and the Jade Horst are rich in dinoflagellate cysts and possess <20% terrestrial palynomorphs. Samples from the Judy Horst contain a wide range of terrestrial palynomorphs, dominated by lycopsid, fern and moss spores, representing c.50% of the recovered palynomorphs. Correspondence analysis of the assemblages implies that Jade did not possess a terrestrial ecosystem; Judy samples define seven groupings of related miospores, all interpreted to represent very low lying, relatively early successional type environments. This implies subaerial exposure of the Judy Horst during the Late Jurassic, which is interpreted to have formed an isolated, low relief, footwall crest island. This study provides a new methodology for investigating rift topography, particularly in cases where the tops of horsts were subsequently removed by erosion. The Judy Island would have separated the Central Graben into its eastern and western arms earlier than previously predicted, in the Late Oxfordian, with consequences for distribution of shallow and deep-marine reservoir quality sediments.

A window into mid-latitudinal Early Eocene environmental variability: a high-resolution palynological analysis of the Falkland site, Okanagan Highlands, British Columbia, Canada

A series of Eocene lake shale deposits from British Columbia, coined the Okanagan Highlands, are dated from associated volcanic ash as mostly from the Early Eocene Climatic Optimum (EECO), the longest persisting of the early Paleogene hyperthermals. In this report we focus on high-resolution palynological sampling of short sequences for the Falkland site to determine if they record centennial- or millennial-scale vegetation change during the EECO. The Falkland shales consist of alternating dark- and light-coloured irregular laminae, along with interleaved tephras from volcanic eruptions. At this site it is apparent that deposition occurred over several millennia. Pollen grains were counted under light microscopy using a standard transect method, with clustering analysis determining whether the data show any long-term trends in plant representation and abundance. Our data show that regional vegetation was impacted by millennial- to centennial-scale climatic variability, as well as the effects of volcanic eruptions. At Falkland there appears to be alterations in vegetation assemblages (birch – golden larch association to fir–spruce) that reflect longer-term (centennial to millennial) climatic transitions (warm/wet to cool/dry). Within this sequence, a period of environmental disturbance (reflected in the presence of multiple volcanic ash layers, wave ripple marks, and a fish-kill layer) has a marked impact on vegetation representation, with a dramatic increase in Abies and Picea pollen at the expense of Alnus and Betula, which do eventually recover. These results suggest mid-latitude millennial-scale climate oscillations in the waning period of the EECO of a similar magnitude to Holocene variability.

Fungal spores from the Palaeogene El Foyel Group of Ñirihuau Basin, Argentina

AbstractThe El Foyel Group is defined in the western section (Andean) of the Ñirihuau Basin, Argentina (41°44′S–71°30′W). It consists of three units: the Troncoso, Salto del Macho and Río Foyel formations. The age of the group and of the formations is still controversial. We studied the fungal remains recovered from 14 palynological samples from outcrops in the group with the intention of providing data to solve this problem. The fungal assemblage found is highly diverse and it is mostly composed of spores of different affinities (mainly ascomycetes). We identified 38 species from 18 genera (Anatolinites,Dictyosporites,Didymoporisporonites,Diporicellaesporites,Diporisporites,Dyadosporites,Exesisporites,Foveodiporites,Hypoxylonites,Inapertisporites,Lacrimasporonites,Monoporisporites,Multicellites,Papulosporonites,Pluricellaesporites,Polycellaesporonites,Staphlosporonitesand one indet.). Moreover, we propose two new species (Hypoxylonites foyelensissp. nov. andPluricellaesporites patagonicussp. nov.) and a new combination (Dyadosporites annulatuscomb. nov.). Most of the species were recovered from samples from the Troncoso Formation (21), while the Salto del Macho and Río Foyel formations showed lesser diversity.Anatolinites subcapsilaris,Dyadosporites subovalis,Inapertisporites subovoideus,Monoporisporites singularovalisandMulticellites ellipticus, biomarkers from the Middle Eocene appeared in the Troncoso and Salto del Salto del Macho formations; whereas indicators of the Eocene–Oligocene, such asDyadosporites elsikii,Didymoporisporonites panshanensis,Foveodiporites elegans,Lacrimasporonites fusoidesandMulticellites leptaleus, were mainly recorded in the Río Foyel Formation. The appearance of the biomarkers mentioned above reinforces the Palaeogene age proposed for the El Foyel Group in previous palynological studies. The record ofHypoxylonites ater(Miocene) in the Salto del Macho formation would expand its range as far back as the Palaeogene.

Palynomorphs of the Fezouata Shale (Lower Ordovician, Morocco): Age and environmental constraints of the Fezouata Biota

The present study documents new palynological investigations of the Fezouata Shale from the Anti-Atlas (Morocco). Palynomorphs were extracted from samples collected from both outcrops and drill cuttings. Outcrop samples were taken near Zagora, and include some that were collected during excavation of stratigraphic horizons where exceptionally well-preserved fossils of the Fezouata Lagerstätte occur. Subsurface samples were taken from the AZ-1 (Adrar Zouggar Mountain) borehole, which was extracted some 300km to the southwest of Zagora. The palynological samples yielded acritarchs, chitinozoans, scolecodonts, conodonts and fragments of graptolites. The abundance and quality of preservation of palynomorphs varies greatly, but rich and diverse assemblages were recovered from several samples. The diversity and composition of the assemblages points to an open shelf environment. Generally mixed preservation states suggest resedimentation or differential transport histories. The acritarchs can be assigned to the diagnostic messaoudensis-trifidum acritarch assemblage, which is typical of the Tremadocian/Floian boundary interval of the Gondwanan margin in high southern palaeolatitudes. The acritarch taxa present in some of the lower parts of the Fezouata Shale including levels of exceptional preservation can be attributed to sub-assemblages 1–2 of the messaoudensis-trifidum assemblage and thus point to a late Tremadocian age of the Fezouata Lagerstätte, confirming biostratigraphic data provided by graptolites of the Araneograptus murrayi graptolite biozone. Chitinozoans from the Fezouata Shale are from the E. symmetrica and E. brevis biozones and include various species that are well-known from several localities on the Gondwanan margin and from other palaeocontinents (Baltica, Laurentia, and South China), demarcating broad links between those regions. The coincidence between index fossils of these three groups, hitherto not all found in the same level, suggests that the age assignments of chitinozoan biozones may be in need of revision.

Rarely reported fungal spores and structures: An overlooked source of probative trace evidence in criminal investigations

The value of pollen and plant spores as trace evidence has long been established, but it is only in the last eight years that fungal spores have been analysed routinely from the same palynological samples. They have greatly enhanced the specificity of links between people, objects, and places. Most fungal species occupy restricted ecological niches and their distributions can be limited both spatially and geographically. Spores may be dispersed over very short distances from the fungal sporophore,11Spore bearing structure. and their presence in any palynological assemblage may indicate a restricted area of ground, or the presence of particular plants (even specific dead plant material). Fungal spores can represent primary, secondary, or even tertiary proxy evidence of a location, and can indicate the presence of a plant even though the plant is not obvious at a crime scene. In some cases, spores from fungi which have rarely been reported, and are considered to be rare, have been of particular value in providing intelligence or evidence of contact. Ten examples are given from case work in which rarely reported or unusual fungi have proved to be important in criminal investigations.

Palynotaphofacies analysis applied to Jurassic marine deposits, Neuquén Basin, Argentina

Fil: Martinez, Marcelo Adrian. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Bahia Blanca. Instituto Geologico del Sur. Universidad Nacional del Sur. Departamento de Geologia. Instituto Geologico del Sur; Argentina

Albian angiosperm pollen from shallow marine strata in the Lusitanian Basin, Portugal

The evolution of angiosperms significantly changed the composition of the terrestrial vegetation during the mid-Cretaceous. In contrast to the wealth of information available on the biology and systematic relationships of early angiosperms, the temporal patterns of their evolution and radiation are poorly constrained. Here we present a continuous angiosperm pollen record from well-dated shallow marine deposits in the Lusitanian Basin, Portugal. The São Julião section provides a solid stratigraphic framework to track angiosperm pollen distribution patterns from the early Albian to early Cenomanian at mid-latitudes. In comparison to previous angiosperm pollen records from the Lusitanian basin, the section shows an extended late Albian succession and provides new insights into the diversification of early angiosperms during this important interval. Productive palynological samples were analysed and 79 different angiosperm pollen types have been recorded. Throughout the Albian angiosperm pollen represent only a minor component of the total palynoflora. The early Albian pollen record is characterized by highly diverse assemblages of monoaperturate pollen of monocot or “magnoliid” affinity and by the first appearance of polyporate and tricolpate pollen of eudicot affinity. A distinct diversification phase among tri- and poly-aperturate pollen (e.g., Cretacaeiporites, Retitrescolpites, Rousea, Striatopollis and Tricolpites) and the presence of conspicuous pollen grains assigned to Dichastopollenites characterize the middle and late Albian palynological assemblages. Thus, the section records a striking sequence of appearances of important angiosperm pollen morphologies. Monocolpates, polyporates and tricolpates appear in the early Albian whereas tricolporates appear from the early part of the late Albian onwards. Furthermore, well-constrained biostratigraphic ranges of selected angiosperm pollen from mid-latitudes are presented. In view of these new data, the temporal framework of the palynological Subzones II-B and II-C in the Potomac Group succession from the Atlantic Coastal Plain, eastern USA is revised to a middle to late Albian age.