Micropaleontology - Wikipedia
Palynology Links. Palynology is the study of all organic-walled palynomorphs that can be found in sedimentary The Micropalaeontological Society is delighted to announce the winner of this year's Micropalaeontology Image Competition!. Micropaleontology is the branch of paleontology (palaeontology) that studies . Centre for Palynology, University of Sheffield, UK · The American Association of Stratigraphic Palynologists (AASP) · Commission. Palynology may help to fill peculiar gaps in the time range of may use the experience developed in more estahlished hranches of micropaleontology to avoid.
Ostracoda Ostracodes are small, bivalved crustaceans that may range from a fraction of a millimeter to many millimeters in size.
They have a long geologic history, ranging back into the Paleozoic Era, with a wide variety of species occupying a wide range of environments, from oceans to bays to lakes to soils.
Their shells are readily fossilized, making them useful for biostratigraphy and paleoenvironmental analyses. Conodonts Conodonts are small, tooth-like phosphatic microfossils found in sedimentary rocks from the Paleozoic Era and earliest Mesozoic Era. They are thought to be produced by an extinct jawless chordate that had some resemblance to eels. They are valuable biostratigraphic indicators; in addition, their color may be used to indicate the thermal history of s sedimentary rock.
More information is available at the University College London web site. Pollen and Spores Pollen and spores provide a record of plant life in the past. Pollen are tiny grains produced by seed plants that contain the male reproductive cells of the plant. The organic-walled remains of pollen grains can be preserved in sediments and fossilized.
Spores of non-seed producing plants such as ferns may also be preserved as organic-walled fossils. Because these types of grains may be produced in abundance by some land plants, palynology the study of pollen, spores, and other organic-walled microfossils can be useful for biostratigraphy and climate reconstruction, particularly in non-marine sediments. More information is available at the University of Arizona web site. Nannofossils Nannofossils are the hard parts of single-celled golden-brown algae.
These hard parts are extremely small calcite plates called coccoliths that are secreted by the algae as it grows. Calcareous nannofossils can be very abundant in the sediments at the bottom of the oceans of today and the past. More information is available at the US Geological Survey web page on nannofossils. Dinoflagellates Dinoflagellates are a group of single-celled, flagellated algae, some of which are preserved as organic-walled microfossils; as such, they are included in the field of palynology.
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.
NAMS What is Micropaleo Page
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.
Paleobotany, Micropaleontology & Mineralogy
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. 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.
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.What is PALYNOLOGY? What does PALYNOLOGY mean? PALYNOLOGY meaning, definition & explanation
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.
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, The Albian Nahr Umr palynomorph assemblage is composed primarily of fern spores mainly Concavisporites and Cyathidites and some gymnosperm pollen grains and show most similarity to those from Iraq.
Paleobotany, Micropaleontology & Mineralogy
This yield of miospores is related to the sand shale ratio which remains moderately high in a marshy environment with fluviatile deposits. Turonian series begins with the Mauddud shelf carbonates at the base, followed by the Ahmadi containing silty shales and limestones in the onshore Dukhan area. Various elater-bearing pollen occurred in unit A of the Ahmadi Formation and remain largely restricted to the area delineated as the elater-bearing phytogeoprovince or African-South American ASA microfloral province Herngreen, The elater-bearing pollen producing plants appear to be the precursors of palms which have in present day an equatorial distribution Srivastava, In this study, the authors supported the extension of the ASA province to Qatar which is part of the equatorial province of the Middle Cretaceous.
Deposition of the Ahmadi unit A took place rapidly in quiet conditions. The Middle Cretaceous succession in the DK-C borehole culminates with the Mishrif shallow-water limestones which is dominated by the skolochorate cyst Floreniinia.
Its dominance implies deposition in open marine conditions Uwins and Batten, Jolley, Centre for Pa-lynological Studies, the University of Sheffield is thanked for offering a place to the first author in the summer of under a British Council Grant.
The authors expres their appreciation to Drs B. Elf-Aquitaine, 5, 2p. Thesis, Ain Shams Univ. Micropalaeontology5, 2p. Micropalaeontology, 4, 1p.