Palynology, Links for Palaeobotanists
Palynology, Pollen, Spore, Acritarchs, Dinoflagellates, NAMS, the North American Micropaleontology Section of the Society for Sedimentary. Palynology, scientific discipline concerned with the study of plant pollen, spores, those aspects dealing with stratigraphy, historical geology, and paleontology. to delineate phylogenetic relationships between fossilized and extant plants. La présence de grains de pollen à élatères, de miospores marqueurs et de 1 - Age relationship of Mesozoic sedimentary rock units in the Arabian Gulf . Micropalaeontology and palynology of the Cretaceous Thamama and Wasia groups.
Based on the presence of these species and their known biostratigraphic ranges, this interval of the DK-C borehole is considered early Cenomanian in age, based on the presence of H. The basal Unit A from depth ft is rich in ostracoda, gastropods and echinoid fragments.
Few and poorly preserved foraminifera are reported in this unit. El Beialy and U. Gymnosperm pollen grains include Classopollis sp. The palynomorph assemblage mentioned above is characteristic for the late Albian to early Cenoma-nian. A recently described dinocyst species, 0. The latter taxon is synonymised with 0. The miospore taxon A. Aptian to Cenomanian occurrences are also reported by Jardine et al. According to Schrank and Lawal and Moullade the A.
This unit also has yielded a single specimen which may be attributed to Brenneripollis reticulatuspreviously reported from the Aptian and Albian sediments of Great Britain and Israel Kemp, ; Hughes et ai, ; Brenner and Bickoff, In summary, the late Albian to early Cenomanian age assignment based on terrestrial and dinocyst data is supported by comparisons of the recovered assemblages with others from the Arabian Gulf, Egypt, Libya, Sudan, Nigeria and south American assemblages.
This age determination accords partly with Sugden and Standring's dating by foraminifers from deep wells throughout the Qatar Peninsula and some offshore areas. Mauddud Formation The interval reported between ft in the DK-C borehole did not yield any palynomorphs due to the non-productive lithologies and the dominance of thick carbonates.
Samples from this horizon were generally poor in foraminifera. This interval is dated as late Albian, based on the presence of the O.
Palynolo-gical evidence indicates that the Nahr Umr Formation is adjusted herein to lie between ft. The presence of O. No samples were available for palynology in this unit. Only one sample was investigated for palynomorphs at depth ft.
The dinocyst assemblage consists mainly of 0. Sporomorphs include Lycopodiacidites sp. Most of the palynomorphs recorded are long ranging but as the sample concerned lacks forms that are more indicative of either Aptian or Albian, they are considered to be of late Albian age, based on the presence of D.
This age assignment is consistent with the age previously determined for this formation in the ofFshore Abu Dhabi area, U. The occurrence of the planktonic foraminifer Planomahna buxtorfi gandulfi latest Albian also supports an age no younger than Albian for this formation Athersuch, There are also similarities with the?
This age assignment was also inferred from the presence of the foraminiferal genus Asanospira sp. The unit A lies between ft, based on lithology. It was herein adjusted to lie between ft, since the underlying sample at depth ft is dated as Aptian by dinocysts. Only one sample at depth ft was investigated for palynomorphs.
This sample is dominated by miospores assigned to Cyathidites minor, Triplanosporites sp. Phytoplankton includes Oligosphaeridium pulcherrimum, Subtihsphaera sp. This interval is devoid of foraminifera, but some ostracodes were recorded.
El Beialy and H. Al-Hitmi The rare presence in this assemblage of tricolpate angiosperm pollen could indicate late middle Albian worldwide even at high latitudes BURDEN and Langille, including in the Arabian Gulf which is part of the equatorial province of the middle Cretaceous Srivastava, Its upper boundary was defined on dinocysts, but the lower boundary on lithological basis, due to unavailability of samples.
In the present study, there is poor local faunal control associated with this interval.
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Although the latter is a diagnostic foraminiferal taxon of Barremian to early Albian age, but an Aptian age is postulated Owen and Nasr, ; Sugden and Standring,based on forams. On the basis of the contained foraminifera, regional correlations with ammonite dated sequences and its relative stratigraphie position, the Shuaiba Formation in the offshore Abu Dhabi area is dated as Aptian to earliest Albian in age as suggested by HASSAN et al.
Diagnostic dinocysts recovered from the sampled interval at depth ft include abundant Pseudo-ceratium pelliferum GOCHT emend. The miospore assemblage includes Concavisporites sp. The dinocyst assemblage consists of taxa which are common in Aptian assemblages elsewhere, including on and offshore Morocco, Egypt, Libya, France, Portugal and southern England.
- Spores and Pollen
Those whose occurrences are thought to be stratigraphically important include Pseudoceratium securigerum Aptian-AlbianP.
V - Palaeoenvironmental reconstruction The Cretaceous sequence under discussion consists predominantly of limestones, often chalky, and is characterized by the absence of evaporites, and by widespread clastic influxes from the West. Throughout this period salt tectonics remained active in Qatar, particularly in the Lower and Middle Cretaceous.
The sedimentary succession in the DK-C borehole starts at the base with the deposition of the Shuaiba Formation, which is the last carbonate cycle of the Thamama Group. One of the striking features of the palynofloras in the Shuaiba Formation is the abundance and low diversity of dinocysts.
Micropalaeontology and palynology of the Cretaceous Thamama and Wasi a groups, Qatar 81 and diversity of the cysts imply deposition in a marine environment of stable salinity. The presence of some peridinioid cysts and foraminiferal test linings suggests that both inner and middle shelf deposits are represented.
Spores and Pollen
This differs from the purely terrestrial character of the same formation in Iraq. At the beginning of the Middle Cretaceous, a major regional uplift of the Arabian shield occurred in the west with subsequent transport of large amounts of clastics onto the platforms. The coastal and alluvial sands of this Albian clastic regime extend to the West of Qatar with increasingly more shale intercalations towards the East, and form the Nahr Umr clastic interval overlying unconformably the Shuaiba Schlum-berger, In particular, his Kristiania lecture of was important in gaining a wider audience.
The methodology of pollen analysis became widespread throughout Europe and North America and revolutionized Quaternary vegetation and climate change research. There is a study of pollen samples taken from sediments of Swedish lakes by Trybom ;  pine and spruce pollen was found in such profusion that he considered them to be serviceable as " index fossils ". Sarauw studied fossil pollen of middle Pleistocene age Cromerian from the harbour of Copenhagen.
Weber appear to be among the first to undertake 'percentage frequency' calculations. Hyde and Williams chose palynology on the basis of the Greek words paluno meaning 'to sprinkle' and pale meaning 'dust' and thus similar to the Latin word pollen. During her time as a student, she developed the first pollen diagram from a sample that depicted the percentage of several species at different depths at Curtis Bog.
This was the introduction of pollen analysis in North America  ; pollen diagrams today still often remain in the same format with depth on the y-axis and abundances of species on the x-axis. They are extracted from sedimentary rocks and sediment cores both physically, by ultrasonic treatment and wet sievingand chemically, by chemical digestion to remove the non-organic fraction.
Palynomorphs may be composed of organic material such as chitinpseudochitin and sporopollenin.
Palynomorphs that have a taxonomy description are sometimes referred to as palynotaxa. Palynomorphs form a geological record of importance in determining the type of prehistoric life that existed at the time the sedimentary formation was laid down. As a result, these microfossils give important clues to the prevailing climatic conditions of the time.
Their paleontological utility derives from an abundance numbering in millions of cells per gram in organic marine deposits, even when such deposits are generally not fossiliferous.
Palynomorphs, however, generally have been destroyed in metamorphic or recrystallized rocks. Typically, palynomorphs are dinoflagellate cystsacritarchssporespollenfungiscolecodonts scleroprotein teeth, jaws and associated features of polychaete annelid wormsarthropod organs such as insect mouthpartschitinozoans and microforams.
Palynomorph microscopic structures that are abundant in most sediments are resistant to routine pollen extraction including strong acids and bases, and acetolysis, or density separation.
Palynofacies[ edit ] A palynofacies is the complete assemblage of organic matter and palynomorphs in a fossil deposit.
The study of the palynofacies of a depositional environment of sediments can be used to learn about the depositional palaeoenvironments of sedimentary rocks. Palynofacies studies are often linked to investigations of the palynology and organic geochemistry of sedimentary rocks. Palynofacies can be used in two ways: Organic palynofacies considers all the acid insoluble particulate organic matter POMincluding kerogen and palynomorphs in sediments and palynological preparations of sedimentary rocks.
The sieved or unsieved preparations may be examined using strew mounts on microscope slides that may be examined using a transmitted light biological microscope or ultraviolet UV fluorescence microscope.
palynology | Definition, Description, & Applications | index-art.info
The abundance, composition and preservation of the various components, together with the thermal alteration of the organic matter is considered. Palynomorph palynofacies considers the abundance, composition and diversity of palynomorphs in a sieved palynological preparation of sediments or palynological preparation of sedimentary rocks.
The ratio of marine fossil phytoplankton acritarchs and dinoflagellate cyststogether with chitinozoansto terrestrial palynomorphs pollen and spores can be used to derive a terrestrial input index in marine sediments. Both types of palynofacies studies are used for geological interpretation of sedimentary basins in exploration geology, often in conjunction with palynological analysis and vitrinite reflectance.
Chemical preparation[ edit ] Chemical digestion follows a number of steps.