Foraminifera

Benthic foraminifera and climate change at the Paleocene/Eocene boundary. New approach. - In the past as in present, climate
changes are considered as major factors inducing physico-chemical parameters fluctuations of marine environment : acidity, oxygenation,
nutrient intake. The disturbance of these parameters affects the benthic foraminiferal biodiversity in view of their extreme sensitivity.
In this context, what are signatures of the global warming IETM (Initial Eocene Thermal Maximum) which marks the Paleocene/
Eocene boundary on the behaviour of benthic foraminifera at Kharrouba (Tunisia) and Zumaya (Spain) sections ?
Quantitative analysis of all combined benthic foraminifera species in each section (Kharrouba and Zumaya) shows a brutal drop of specific
richness, a signal of global warming impact. This upsetting is observed, not only on specific richness, but also on taxa distribution
within sediments : Endobenthic Calcareous (EnC) and Endobenthic Agglutinated (EnA) ; and at their surfaces : Epibenthic Agglutinated
(EpA) and Epibenthic Calcareous (EpC).
Considered separately, the analysis of these four assemblages is a new approach allowing to better understanding the behaviour of
benthic foraminiferal during the global warming (IETM) of the Paleocene-Eocene transition. Despite the Epibenthic percentage change
is done in opposite way for Kharrouba and Zumaya sections, the percentages of Epibenthic Calcareous (EpC) and Epibenthic Agglutinated
(EpA), considered separately, show a different reality. These two groups vary in same way at both sections.
In contrast, the endobenthic behaviour is more complex. The variation of Endobenthic Calcareous (EnC) is done in the same direction
in the two sections, showing a decrease in their frequency. But, for Endobenthic Agglutinated (EnA), the frequency varies in opposite
way. For the Zumaya section they were up 36.65%, while in the Kharrouba section shows a slight decrease of 3.22%.
The new reorganization of these four groups at lower Eocene is explained either by massive extinctions mainly for calcareous species
and dissolution of their tests ; either by a passive dispersal of agglutinated species which are spared of the test dissolution. The precariousness
of calcarous tests (into the sediments as at their surface) gives them quality as a best indicator of ocean acidification for the
North Atlantic (Zumaya) and the Tethyan Ocean (Kharrouba). The increase of acidity is probably due to limitation of thermohaline
circulation during global warming (IETM) in northern of Atlantic Ocean causing a much stronger corrosion to calcareous tests.

The sedimentary litho sections of Ariyalur are the
archetype field sites for the study of Cretaceous events and
environments. Pre-Cretaceous/Albian to Maastrichtian age
lithosections outcrop in this area depicting many geological
episodes, sea level changes and fossils records. These
sedimentary rocks are enriched in carbonate content as
deposited in shallow marine conditions along the basin
margin at shallow water depth. They are being exploited for
cement industry at a rapid pace thus leading to their
disappearance from their habitat. Therefore, we propose
that few sedimentary sections (at least in part) like Terani
clay mine, Kallakkudi limestone mine section and other
quarry sections wherein Aptian-Maastrichtian rock
formations are exposed needs geo-heritage status. These
outcrop sections if preserved by protecting from mining
activities will serve for future geosciences research. In
addition to the Sattanur Fossil wood site, the Karumbayam
Ammonite horizon site must be preserved as heritage sites.
We therefore propose construction of a macro scale
Cretaceous litho section at GSI monument site at Sattanur
which can serve for future Cretaceous stratigraphic studies

The main distribution area of the Sarmatian sediments in Georgia is the Transcaucasian intermountain area. According to the tectonic zoning scheme of Georgia (Gamkrelidze, 2000), Kartli depression, which is the object of study, participates in the structural-facial composition of the eastern subsidence molassic zone of the Transcaucasian intermountain area. The Sarmatian sediments widespread in this area are distinguished in facies diversity and represent a prospective stratigraphic interval of natural hydrocarbons accumulation.
Over the past years, quite rich factual material has accumulated on the Sarmatian sediments of the Kartli depression, including paleontological and biostratigraphical. The Sarmatian sediments are well studied makro- and micro-faunally and their detailed stratigraphic division has been accomplished as well (Buleishvili, 1960; Gruzinskaya, 1967; Koiava, 2006).
In recent years, during oil exploration special attention is attracted to the identification of paleo-deltas. There was established certain regularity, according to which the largest oil fields are related just to the paleo-deltas. During the oil exploration works micro-paleontological investigations (foraminifers, ostracods) are of special importance.
The Sarmatian deposits of the Kartli depression are well studied, in terms of foraminifers (Koiava, 2006). As for the Ostracods, this group is at the initial stage of the study, and studying them in complex with the foraminifera will make a significant contribution to the paleontological/biostratigraphic knowledge of the region and will help petroleum geologists in hydrocarbon exploration.
That is why the Sarmatian sediments of Kartli Depression have been selected as the topic for the Master's thesis, and the research method is based on micropaleontology (Foraminifera, Otracoda). The aim of the research is establishment of the foraminifera and ostracod complexes of the Kartli depression Sarmatian sediments and according to them determination of biostratigraphic boundaries, stratigraphic division of the studied sediments, monographic study of the Sarmatian foraminifers and ostracods. 
For this purpose, in the limits of Kartli depression we have studied three sections of the Sarmatian sediments: 1 - in the Nadarbazevi ravine; 2 - in the environs of the Bebristsikhe (town of Mtskheta); 3 - in the gorge of river Noriostskali.
As a result of the study, in the Kartli depression, complexes of foraminifers and ostracods characteristic of the Lower and Middle Sarmatian are distinguished. Their regular variability in time and space was established and due to that stratigraphic division of the studied sediments was carried out. 11 species of 3 foraminifer genera and 9 species of 4 ostracod genera are studied monographically. For the first time in the bounds of Kartli depression, a complex study of the Sarmatian sediments based on two groups of microfauna - foraminifers and ostracods was carried out.

This book aims to address the deficiencies of contemporary evolution studies by evaluating Multi-Torus or Morphogenetic Torus Theory using the fossil record. The book begins with description of and discussion of one of most recently recognized members of the Ediacaran biota, a fossil that looks astonishingly like a fossilized morphogenetic torus. This is followed by evaluation a newly discovered giant trilobite with characteristics that appear to support toroidal morphogenesis theory. The book then looks at an application of the model to scleritome theory (i.e., the theory of shell evolution) and to the Cambrian origin of mollusks and brachiopods, and as a result will develop a new and powerful dual application of torus scleritome theory. Next follows focus on the early development of cephalopods and a new variant of the torus called hypertorus. Finally, the book considers a counterexample to toroidal morphogenesis in the growth of marine microbes known as foraminifera. Using a newly discovered foraminiferal microbiota (that turns out to be exactly contemporary with the new giant trilobite), the book explores the metacellular/chambering style of morphogenesis that stands in direct contrast to toroidal morphogenesis as a parallel morphogenetic system.

The Cretaceous System, proposed by d'Omatius d'Halloy in 1822, takes its name from
Creta-the Latin for chalk. Chalk is the most distinctive rock type of the System, not only
in Britain (Fig. 7.1), but over a considerable area of the globe. Upper Cretaceous sediments at one time covered the whole of northwest Europe, save for a few isolated
areas of ancient massifs like the Baltic Shield. Today, sediments of Cretaceous age are limited (onshore) to a narrow band down eastern England, together with a wide tract
of country across southern England. Offshore, Cretaceous strata are more extensive,
covering, or known from, large areas of the North Sea Basin, the English Channel, the Celtic Sea and the South West Approaches Basin.

The intertrappeans associated with the Deccan volcanics of Jhilmili and Rajahmundri were reported to be marine, but the Anjar intertrappeans were previously advocated to have deposition in lacustrine or freshwater environment. The present investigation carried out on 26 samples collected from infratrappean, intertrappean and intratrappeans beds in and around Viri village, Anjar area, Kachchh district, India. The infratrappean (L-1), intratrappeans at the bottom as well as on the top (L-2 and L-6) are considered non-marine in origin as no foraminifera are recorded within these beds. Samples from the central portion of the area documented foraminiferal population which was not described earlier. Foraminiferal assemblages consisting of mainly Rotalia, Elphidium, Quinqueloculina, Nonion group of species within the intermediate intertrappean and intratrappeans (L-3 to L-5) are inferred to be deposited under shallow marine or ocean connected lacustrine environment. Presence of siliciclastic grains, rock-fragments, peloids and bioclasts also clearly indicate shallow water deposition. Increased abundance of Nonion spp., Quinqueloculina spp. as well as presence of planktic foraminifera (Pseudogloborotalia ranikotensis and Globigerina triloculinoides) within the intertrappean bed (L-3) is suggestive of relatively higher water depth at the site during deposition. Changes in deposition environments from non-marine to marine and finally non-marine sequence from older to younger indicate events of marine transgression followed by a regression phase.

Foraminifera (single-celled protists) have a long geological record. They are both numerous and taxonomically diverse in assemblages throughout the Mesozoic and Cenozoic and have been used extensively in the oil industry since Józef Gryzbowski studied the stratigraphy of the Potok Oilfield (southern Poland) in the late 19th century. Both planktic and benthic foraminifera are used for biostratigraphy in various locations throughout the world, based on both processed residues and—where appropriate—thin-sections. In the Cretaceous successions of the Gulf of Mexico and the passive margins of the Atlantic Ocean, foraminifera provide vital evidence of changing paleoecology, paleoceanography, and major extinction events. This is particularly significant in the interpretation of oceanic anoxic events in the mid-Upper Cretaceous and the extinction events associated with the Cenomanian/Turonian and Cretaceous/Paleogene boundaries. By using planktic:benthic ratios and various forms of morphotype analysis—coupled with an understanding of modern ecology—the distribution of foraminifera are often important indicators of sea-level changes, ocean acidification events, and the low-oxygen environments, which often create hydrocarbon source rocks. Shelf successions below modern-day oxygen-minimum zones, while supporting different species from those from fully oxygenated environments, do not normally generate anoxic sediments and restricted assemblages: there must be other factors, such as basin isolation, involved. Models developed for the offshore basins of Brazil have been applied in many areas of the world, with the neritic areas of the Gulf Coast and North Atlantic margins providing many examples of how such models can be applied elsewhere.

The Foraminifera abbreviated as forams are primarily marine unicellular micro organisms with internal shells known as tests that are divided into chambers. These tests form the basis of foraminiferal classification, and is the only structure to survive fossilization. The study of these organisms is essential in the study of marine environment. Fossil foraminifera are useful in biostratigraphy, paleoecology, and paleobiogeography. This article is aimed at providing a brief description, classification and applications of Foraminifera.

In marine environments Ostracoda and Foraminifera have been very successful invaders. During the Phanerozoic they colonised the majority of shallow, marginal to deep water, fully marine habitats. Both groups had developed physiological adaptations which pre-adapted them to the invasion of new marine habitats.
They adopted a broad range of feeding strategies and reproduction modes. The production of resting stages and brood care may also have contributed to them being efficient invaders. They are also both highly tolerant to variations in salinity. The first invasions of non-marine habitats by ostracods appear to have taken place at the turn of the Devonian and Carboniferous. It is estimated that there had been between 9 and 12 independent invasions of fresh waters by the ostracods. In contrast Foraminifera are typically marine organisms, and only a few species of
agglutinated and organic-walled Foraminifera are to be found in brackish and freshwater environments. Agglutinated species build their test using ambient
components but are not commonly regarded as calcifying organisms. An impact of salinity on foraminiferal calcification has been observed in several studies. It seems
that Foraminifera are incapable of constructing a fully calcified test in low salinity regimes; they use sea water not only as a source of ions to construct shell, but also
as a biomineralisation solution. Thus, the success of ostracods in invading freshwater habitats can be attributed to their development of a more effective mechanism
of calcification in low mineralisation waters. The core question of this study is to examine possible causes for the differences in success between the two taxa.

A reclassification of the agglutinated foraminifera (within the Class Foraminiferea) is presented, consisting of three sub-classes, seven orders, 18 suborders, 32 superfamilies, 122 families, 148 subfamilies, and containing a total of 832 valid genera is presented. The classification is modified from the suprageneric scheme used by Kaminski (2004a), and incorporates all the new agglutinated genera described up to and including the year 2010. The major differences from the Kaminski (2004a) classification are (1) the subdivision of the Foraminifera into three supraordinal groups according to the molecular studies of PawÓowski and co-workers (2) the inclusion of the allogromiids in the classification alongside the astrorhizids (3) the inclusion of the xenophyophorids within the Astrorhizida at superfamily rank, (4) the merging of all pseudo-bilocular and pseudo-multichambered forms within a single subclass and (5) the revision of the schlumberigerinids to encompass all miliolids with an agglutinated wall. Numerous minor corrections and updates have been made to the generic classification based on the recent literature.

The Holocene evolution of the Canning Coast of Western Australia has largely been overlooked so far mainly due to its remoteness and low population density. We report on new data from a sequence of foredunes inside the macro-tidal Admiral Bay, 110 km southwest of Broome. Based on sediment cores, differential global positioning system (dGPS)-based elevation transects, and stratigraphical analyses on outcrops of the relict foredunes, we aim at reconstructing Holocene coastal changes and relative sea levels (RSLs), as well as identifying and dating imprints of extreme-wave events. Sedimentary analyses comprise the documentation of bedding structures, foraminiferal content and macrofaunal remains, grain size distribution, and organic matter. The chronological framework is based on 26 carbon-14 accelerator mass spectrometry (14C-AMS) datings. Marine flooding of the pre-Holocene surface landward of the 2.5 km-wide foredune barriers occurred 7400–7200 cal BP, when mangroves colonized the area. After only 200–400 years, a high-energy intertidal environment established and prevailed until c. 4000 cal BP, before turning into the present supralittoral mudflat. During that time, coastal regression led to beach progradation and the formation of aligned foredunes. Drivers of progradation were a stable RSL or gradual RSL fall after the mid-Holocene and a positive sand budget. The foredunes overlie upper beach deposits located up to >2 m above the present upper beach level and provide evidence for a higher mid-Holocene RSL. Discontinuous layers of coarse shells and sand are intercalated in the foredunes, indicating massive coastal flooding events. One such layer was traced over three dune ridges and dated to c. 1700–1550 cal BP. However, it seems that most tropical cyclones induce net erosion rather than deposition at aligned foredunes and thus, they are only suitable for reconstructing temporal variability if erosional features or sedimentation reliably tied to these events can be identified and dated accurately.

Analysis of a 630m section of an exploration well penetrating the distal part of the Congo Fan (~2000m water depth) yielded high abundance and diversity assemblages of agglutinated and calcareous benthic foraminifera. Planktonic foraminifera constrain the age to Early – Middle Miocene, and d 18 O records reveal the Mi1 (~16.3 Ma) isotopic shift. Relatively few taxonomic studies of deep-water calcareous and agglutinated benthic foraminifera exist from this time period in this locality. All species encountered are therefore taxonomically described and documented using SEM photography (over 170 species), along with 27 species of planktonic foraminifera. Faunas show close affinities to those of the eastern Venezuela Basin, Gulf of Mexico and Central Paratethys. Seven assemblages are defined and analysed using morphogroup analysis and Correspondence Analysis, documenting the response of benthic foraminifera to three primary environmental-forcing factors; energy levels in the benthic boundary layer, oxygen levels relating to changing surface water productivity, and fluctuations in the level of the CCD. Near the top and bottom of the studied section both foraminiferal abundance and diversity decrease, corresponding with increased sand content implying greater energy levels and environmental disturbance. The majority of the section consists of shales with very low percentage sand, high foraminiferal abundance and diversity, and high sedimentation rates of ~10cm/kyr. Morphogroup analysis reveals a major switch in the fauna at around oxygen isotope event Mi1, with the transition from an epifaunal-dominated Cibicidoides assemblage to shallow infaunal-dominated Bulimina assemblage. We regard this as likely due to expansion of the oxygen minimum zone (paleobathymetric estimates are ~1000m) related to increased surface-water productivity and global cooling. Shifts in calcareous foraminiferal percentage over the studied interval overprint these signals and are believed to be related to a shoaling CCD, linked to reduced oceanic acidity and global atmospheric CO2 levels during the early Middle Miocene Monterey Carbon Isotope Excursion.

The Lech
owka section comprises the most complete CretaceousePaleogene (K-Pg) boundary succession
in Poland and is among 29 sites worldwide with the youngest ammonite record. Here, cephalopods
(ammonites and nautilids), organic-walled dinoflagellates (dinocysts) and foraminifera from the uppermost
Maastrichtian interval are studied. In terms of ammonite biostratigraphy, the upper Maastrichtian
Hoploscaphites constrictus crassus Zone is documented up to a level 120 cm below the K-Pg
boundary. There is no direct, ammonite-based evidence of the highest Maastrichtian H. constrictus
johnjagti Zone. However, the predominance of the dinocyst marker taxon Palynodinium grallator suggests
the presence of the equivalent of the uppermost Maastrichtian Thalassiphora pelagica Subzone, which is
correlatable with the H. c. johnjagti ammonite Zone. The planktonic foraminiferal assemblage is coeval
with that from the H. c. johnjagti Zone as well. These data indicate that the top of the Maastrichtian at
Lech
owka is complete within the limits of biostratigraphic resolution, albeit slightly condensed. The
dinocyst and foraminiferal assemblages are dominated by taxa that are characteristic of high-energy,
marginal marine environments. A reduction in test size among the calcareous epifaunal benthic foraminifera
is observed at a level 50 cm below the K-Pg boundary, which is possibly related to environmental
stress associated with Deccan volcanism.

Episodes of symbiont-bleaching have been documented in field studies of epiphytic populations of the dinoflagellate-bearing foraminiferan Sorites dominicensis from Jupiter Sound in the Indian River Lagoon, Florida, and Carrie Bow Cay and Twin Cays, Belize. In August 2003, 13–16% of the population in Jupiter Sound exhibited evidence of bleaching, with cytoplasm that was either mottled or totally white. In July 2005, 18% of the population on the reef flat off Carrie Bow Cay, and 4% of the population in the tannin-stained waters of Boston Bay, Twin Cays, exhibited signs of bleaching. Symbiont bleaching in soritid foraminiferans may be a more widespread and recurrent phenomenon than has previously been recognized. Bleaching appears to be triggered by a combination of environmental factors that are similar to the conditions that trigger bleaching in corals, such as: subaerial exposure during extreme low spring tides in the summer months, high water temperatures, increased irradiance, exposure to light in the ultraviolet or blue light spectra, and periodic disturbance by hurricanes. The endosymbionts in S. dominicensis, and other soritid foraminiferans, are members of the Symbiodinium clade of dinoflagellates that comprise the zooxanthellae in cnidarians and molluscs, thus this foraminiferal host-symbiont system has potential utility as a model system for the experimental study of the cellular and molecular mechanisms underlying coral bleaching. 

An exploration well from the Gulf of Mexico, Amoco Viosca Knoll-915, has been studied in order to document the Neogene foraminiferal assemblages. Ditch cuttings samples from the Amoco V.K. 915 well yielded diverse assemblages of agglutinated and calcareous benthic foraminifera over a stratigraphic interval of 2940 m. Three species associations can be identified in the studied interval; the stratigraphical location of these associations is evident when total agglutinated species abundance for each sampling interval is plotted. In this study we use a combination of morphotype habitat preference and test functional morphology to interpret depositional environments. The associations indicate a change from a well-ventilated water column, to the development of a strong oxygen minimum zone characterised by alveolar foraminifera. The species composition of the lowermost association indicates a depositional environment dominated by fine-grained overbank fines and channel levee deposits, in agreement with sedimentological data. Colour plates of key agglutinates species are presented, created using digital image manipulation techniques (Palaeovision Technique, NHM).