The age and palaeoecology of the St Erth Beds, southern England, based on planktonic foraminifera

1982 ◽  
Vol 119 (2) ◽  
pp. 201-205 ◽  
Author(s):  
D. Graham Jenkins
Keyword(s):  
Planktonic Foraminifera ◽  
Photic Zone ◽  
Late Pliocene ◽  
Southern England ◽  
Neogloboquadrina Pachyderma ◽  
First Time

SummaryPlanktonic foraminifera are recorded for the first time from the St Erth Beds but they are small and very rare. A late Pliocene G. inflaia Zone age is postulated on the presence of Globorotalia inflata and dextrally coiled Neogloboquadrina pachyderma. It is suggested that the depth of water at the time of deposition was much less than 100 m, possibly in the photic zone, and the palaeotemperature was in the range of 10–18 °C.

Late Pliocene to Early Pleistocene Planktonic Foraminifera from Northern Indian Ocean (Andaman and Nicobar Islands): Interpretation on Cooling Event and Ocean Upwelling

2021 ◽  
Vol 51 (3) ◽  
pp. 115-138
Author(s):  
Rikee Dey ◽  
Amit K. Ghosh ◽  
Ajoy Kumar Bhaumik ◽  
Arindam Chakraborty ◽  
Stuti Saxena ◽  
...  
Keyword(s):  
Indian Ocean ◽  
West Coast ◽  
Planktonic Foraminifera ◽  
Early Pleistocene ◽  
Northern Indian Ocean ◽  
Late Pliocene ◽  
Globigerina Bulloides ◽  
Neogloboquadrina Pachyderma ◽  
Nicobar Islands ◽  
Identification Analysis

ABSTRACT Thirty-two planktonic foraminiferal taxa have been identified based on Bright Field microscopic study as well as Scanning Electron Microscopy on the samples collected from the outcrop adjacent to the type section of Neill West Coast Formation at Neil Island of Ritchie's Archipelago, northern Indian Ocean. The planktonic foraminiferal taxa belong to ten genera viz., Dentoglobigerina, Globigerina, Globigerinoides, Globoconella, Globorotalia, Globorotaloides, Globoturborotalita, Neogloboquadrina, Orbulina, and Trilobatus. A number of statistical analyses have been done in addition to taxonomic study to interpret the palaeocenographic scenario. We performed PCA analysis on the foraminiferal content of the samples to test the relatedness. Two biozones have been established by Stratigraphically Constrained Cluster Analysis (CONISS). We used SHEBI (SHE analysis for biozone identification) analysis to precisely demarcate seven biozones. Attempts have been made to decipher the Plio–Pleistocene boundary in the Neill West Coast Formation based on specific zonal markers. The presence of some taxa (e.g., Globoconella inflata, Globigerina bulloides, and Neogloboquadrina pachyderma) indicates the initiation of a cooling event from late Pliocene onwards. An event of ocean upwelling also has been identified based on the presence of Globigerina bulloides, Neogloboquadrina pachyderma, and N. dutertrei from the late Pliocene to early Pleistocene of the northern Indian Ocean that also correlates with palaeoceanographic records known from other upwelling regions.

CARBONATE DISSOLUTION AND ULTRASTRUCTURAL BREAKDOWN IN PLANKTONIC FORAMINIFERA IN THE SEA OF OKHOTSK

2017 ◽  
Author(s):  
Alexandra Romanova ◽  
Alexandra Romanova ◽  
Vladimir Anin ◽  
Vladimir Anin ◽  
Sergey Pletnev ◽  
...  
Keyword(s):  
Sea Of Okhotsk ◽  
Planktonic Foraminifera ◽  
Carbonate Dissolution ◽  
Calcite Dissolution ◽  
The Sea Of Okhotsk ◽  
Globigerina Bulloides ◽  
Neogloboquadrina Pachyderma ◽  
Thin Walled ◽  
Shell Fragments ◽  
Degree Of Fragmentation

80 sediment stations collected along the meridian transect across the Sea of Okhotsk were studied in order to reveal patterns of dissolution based on planktonic foraminifera. The degree of calcite dissolution intensity from planktonic foraminifera determined by different indices (degree of fragmentation, presence of susceptible to dissolution species, benthos/ plankton ratio). The highest degree of dissolution evidenced by a large number of shell fragments and corroding walls were found in sediments from the area of the Kuril Islands. The most revealing measure of probable dissolution of foraminiferal shells in the central part of the sea is a low number and lack of thin-walled species. The effects of dissolution on foraminiferal shells were studied for dominated species Neogloboquadrina pachyderma sin and Globigerina bulloides using a scanning electron microscope. The results are important for understanding processes of sedimentation, the paleo-oceanologial reconstructions and for obtaining reliable results in isotope analyzes.

scholarly journals Planktonic foraminifera genomic variations reflect paleoceanographic changes in the Arctic: evidence from sedimentary ancient DNA

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joanna Pawłowska ◽  
Jutta E. Wollenburg ◽  
Marek Zajączkowski ◽  
Jan Pawlowski
Keyword(s):  
Ancient Dna ◽  
Sequence Data ◽  
Planktonic Foraminifera ◽  
Molecular Ecology ◽  
The Arctic ◽  
Marine Biodiversity ◽  
Neogloboquadrina Pachyderma ◽  
Rna Genes ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract Deciphering the evolution of marine plankton is typically based on the study of microfossil groups. Cryptic speciation is common in these groups, and large intragenomic variations occur in ribosomal RNA genes of many morphospecies. In this study, we correlated the distribution of ribosomal amplicon sequence variants (ASVs) with paleoceanographic changes by analyzing the high-throughput sequence data assigned to Neogloboquadrina pachyderma in a 140,000-year-old sediment core from the Arctic Ocean. The sedimentary ancient DNA demonstrated the occurrence of various N. pachyderma ASVs whose occurrence and dominance varied through time. Most remarkable was the striking appearance of ASV18, which was nearly absent in older sediments but became dominant during the last glacial maximum and continues to persist today. Although the molecular ecology of planktonic foraminifera is still poorly known, the analysis of their intragenomic variations through time has the potential to provide new insight into the evolution of marine biodiversity and may lead to the development of new and important paleoceanographic proxies.

Oceanographic implications of recent planktonic foraminifera along the southern Australian margin

1998 ◽  
Vol 49 (5) ◽  
pp. 439 ◽  
Author(s):  
Qianyu Li ◽  
Brian McGowran
Keyword(s):  
Cold Water ◽  
Saline Water ◽  
Planktonic Foraminifera ◽  
South Australia ◽  
Last Interglacial ◽  
The South ◽  
Leeuwin Current ◽  
Neogloboquadrina Pachyderma ◽  
Great Australian Bight ◽  
Subtropical Species

The distribution of planktonic foraminifera along the southern Australian margin is strongly gradational from warmer assemblages in the west to more temperate assemblages in the east. This pattern follows a decreasing temperature gradient generated by the warm Leeuwin Current which flows southward and then eastward on the southern margin. The abundances of tropical and subtropical species including Globorotalia menardii and Globigerinoides trilobus s.l. decrease rapidly after rounding the south-western corner, while the temperate index species Globorotalia inflata increases and subsequently dominates the fauna towards the east, especially on the Lincoln and Lacepede shelves of South Australia. This W–E gradation is also observed in the relict Pleistocene assemblages, indicating that the Leeuwin Current has been influential since at least the last interglacial time. The interaction between the warm and saline water from the Great Australian Bight and cold water from the south produced an assemblage in deeper parts of the Bight with abundant small species such as Globigerina falconensis, Globotur-borotalita rubescens, Neogloboquadrina pachyderma and Turborotalita quinqueloba.

scholarly journals On the age and correlation of the St. Erth Beds, S.W. England, based on planktonic foraminifera

1986 ◽  
Vol 5 (2) ◽  
pp. 93-105 ◽  
Author(s):  
D. Graham Jenkins ◽  
John E. Whittaker ◽  
R. Carlton
Keyword(s):  
Planktonic Foraminifera ◽  
Late Pliocene ◽  
Stratigraphic Ranges

Abstract. The paper illustrates and describes 15 species of planktonic foraminifera from the St. Erth Beds, Cornwall, S.W. England. The overlap of the stratigraphic ranges of Globorotalia inflata (d’Orbigny), G. praehirsuta Blow, G. tosaensis Takayanagi & Saito, Pulleniatina primalis Banner & Blow, Neogloboquadrina humerosa (Takayanagi & Saito) and dextrally coiled N. pachyderma (Ehrenberg) places the age of the fauna in the Globorotalia inflata Zone, Late Pliocene. The absence of Globorotalia puncticulata (Deshayes), G. truncatulinoides (d’Orbigny) and Neogloboquadrina atlantica (Berggren) confirms this age assignment and with the presence of G. inflata (d’Orbigny), the deposition of St. Erth beds can now be accurately placed at between 2.1 and 1.9 Ma. For this paper, it has been acceped that the Pliocene-Pleistocene boundary is marked by the first evolutionary appearance of G. truncatulinoides at about 1.9 Ma.

scholarly journals New records of planktonic foraminifera in the Shuaiba Formation (Aptian Age), Mesopotamian plain, South of Iraq

2019 ◽  
pp. 1322-1335
Author(s):  
Zain Alabdeen A. Al-Shawi ◽  
Maher M. Mahdi ◽  
Abbas H. Mohammed
Keyword(s):  
New Records ◽  
Planktonic Foraminifera ◽  
Oil Fields ◽  
The Other ◽  
Arabian Plate ◽  
History Of ◽  
South Of Iraq ◽  
The Many ◽  
First Time ◽  
Southern Iraq

Shuaiba Formation is an important formation in Iraq, because of their deposition in the important period during the geological history of Arabian plate. The study is focused on a number of selected wells from several fields in southern Iraq, despite the many of oil studies to Shuaiba Formation but it lacks to paleontological studies. Four selected wells are chosen for the current study, Zb-290, Ru-358, R-624, WQ1-353, the selected wells are located within different fields, these are Zubair, Rumaila and West Qurna Oil Fields. In this study fourteen species followed to genus Hedbergella were discovered for first time as well as three genera followed to genus Heterohelix in the Shuaiba Formation at the different oil fields, Hedbergella tunisiensis Range Zone is suggested biozone to the current study, the age of this biozone is Aptian, most of the other genera located within this zone.

scholarly journals Eastern Mediterranean foraminiferal palaeoecological response to Mid-Late Pliocene climatic regime: A preliminary note.

2016 ◽  
Vol 47 (1) ◽  
pp. 112 ◽  
Author(s):  
H. Drinia ◽  
A. Antonarakou ◽  
S. Mihalakopoulos ◽  
E. Tsiolakis
Keyword(s):  
Marine Sediments ◽  
Sedimentation Rate ◽  
Eastern Mediterranean ◽  
Planktonic Foraminifera ◽  
Preliminary Note ◽  
Climatic Influence ◽  
Late Pliocene ◽  
Orbital Perturbations ◽  
Southern Cyprus ◽  
Climatic Regime

The main objective of this work is to investigate the climatic influence on the sedimentation during mid to late Pliocene in Cyprus island. For this reason, a section located in Pissouri sub-basin, southern Cyprus, was chosen to be studied. The section comprises a nearly uninterrupted succession of marine sediments, dominated by grey marls, which are cyclically alternating with yellowish silty marls. The identification of age diagnostic planktonic foraminifera suggests a mid to upper Pliocene age. The calculated faunal parameters document cyclic fluctuations consistent with shifts in such climate belts. A good age resolution of the cycles and an indication of sedimentation rate would be required in order to connect cyclicity to orbital perturbations.

scholarly journals Reconstructing abrupt climate changes of the last deglaciation & Holocene: Pollen & biomarker analyses from the Portuguese Margin

2020 ◽  
Author(s):  
Anna Cutmore ◽  
Blanca Ausin ◽  
Timothy Eglinton ◽  
Mark Maslin ◽  
Chronis Tzedakis
Keyword(s):  
High Resolution ◽  
Planktonic Foraminifera ◽  
Pollen Record ◽  
Last Deglaciation ◽  
Leaf Wax ◽  
Close Proximity ◽  
Terrestrial Environments ◽  
Climate Events ◽  
First Time ◽  
Millennial Scale

<p>In light of the current rate of anthropogenic climate change, it is becoming increasingly critical to enhance knowledge of past abrupt climate events and subsequent responses of the Earth system. One period that can provide such insight is the last ~28 kyr, with several abrupt changes occurring over the course of the deglaciation. The Portuguese Margin has been an ideal location to study the impacts of these abrupt climate events on marine and terrestrial environments.  The combined effect of the narrow continental shelf and close proximity to the Tagus and Sado rivers, lead to the rapid delivery of a high quantity of sediment, including our pollen and biomarker proxies, to the Tagus Abyssal Plain. Joint terrestrial and palaeoceanographic analyses from the same sediment samples enable an in situ assessment of the relative timing of changes in palaeoceanographic and terrestrial proxies.</p><p> </p><p>Here we document the response of western Iberian vegetation to millennial and centennial-scale changes, particularly changes in moisture availability, over the deglaciation and Holocene, by combining (for the first time at a Portuguese Margin site) pollen and leaf-wax isotopic biomarker records (δ<sup>13</sup>C and δD) from core SHAK06-5K. A high-resolution pollen record (every 2cm) and lower-resolution n-alkane δ<sup>13</sup>C and δD records spanning 28kya are compared with high-resolution XRF sediment and planktonic foraminiferal d<sup>18</sup>O analyses from the same core.  The sequence is supported by high-resolution age control, based on 40 Accelerator mass spectrometry (AMS) <sup>14</sup>C dates from monospecific samples of the planktonic foraminifera, <em>Globigerina bulloides</em>.</p><p> </p><p>Our pollen record indicates the rapid response of regional vegetation to centennial changes and millennial-scale climate events, with forest expansion during the warm interglacial/ interstadial Bølling-Allerød and Holocene, and forest contraction and steppe expansion during cold glacial/ stadial conditions of the Last Glacial Maximum and Younger Dryas. Comparing our pollen and n-alkane biomarker data with the XRF Zr:Sr ratio and planktonic foraminiferal δ<sup>18</sup>O records, a clear synchroneity can be seen in the timing of millennial-scale changes in all records.  The millennial-scale changes in our leaf wax n-alkane δD and δ<sup>13</sup>C records can be explained by both vegetation composition and growing season water availability. </p>

Observations on Some Helminth Parasites from Ducks in Southern England

1955 ◽  
Vol 29 (1-2) ◽  
pp. 17-26 ◽  
Author(s):  
K. N. Soliman
Keyword(s):  
Helminth Parasites ◽  
Domestic Duck ◽  
Southern England ◽  
First Time

1. Thirteen different species of helminth parasites were encountered in eighteen ducks (six Muscovy and twelve Khaki Campbells) on a farm in Berkshire. Of these parasites, four were trematodes, five cestodes, three nematodes and one Acanthocephala.Hymenolepis collaris, Trichostrongylus tennis and Filicollis anatis are recorded from the domestic duck in Britain for the first time. Hymenolepis anatina and Hymenohpis abortiva are recorded for the first time in England.

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