Agglutinated Foraminiferal Acmes and Their Role in the Biostratigraphy of the Campanian–Eocene Outer Carpathians

The biostratigraphy of the Outer Carpathians is based mainly on the ranges of agglutinated foraminifera. Species acmes provide the opportunity to enhance and support the existing biozonations. Assemblages of agglutinated foraminifera from the Campanian to Eocene of various tectonic-structural units were analyzed in terms of their qualitative and quantitative occurrence. In this stratigraphic interval, 19 species display significantly increased abundance within a relatively short interval: Caudammina gigantea (Geroch) (upper Santonian–lowermost Maastrichtian), Caudammina ovulum (Grzybowski) (Campanian–Danian), Placentammina placenta (Grzybowski)-Saccammina grzybowskii (Schubert) (upper Campanian–Danian), Caudammina excelsa (Dylążanka) (lowermost Maastrichtian–Danian), Caudammina ovuloides (Grzybowski) (Danian–Selandian), Hormosina velascoensis (Cushman) (upper Danian–Selandian), Praesphaerammina gerochi (Hanzlíková) (Thanetian), Glomospira charoides (Jones et Parker)-Glomospira gordialis (Jones et Parker) (uppermost Thanetian–lowermost Ypresian), Trochammina spp. (upper Thanetian–lower Ypresian), Reticulophragmium amplectens (Grzybowski) (Lutetian–Bartonian), Reophax duplex (Grzybowski)-Reophax “pilulifer” Brady group of taxa (Lutetian–Priabonian), Haplophragmoides walteri (Grzybowski)-Haplophragmoides nauticus Kender, Kaminski et Jones (Lutetian–Bartonian), Spiroplectammina spectabilis (Grzybowski) (Lutetian–Priabonian), “Ammodiscus” latus Grzybowski (Bartonian–Priabonian), Praesphaerammina subgaleata (Vašíček) (Lutetian–Bartonian). The biostratigraphic position and quantitative data of species with increased abundance are presented.

What do shallow cores tell us when drilled in an anthropogenically active delta from northwest Italy?

<p>This study aims at checking the quality of the sedimentary record preserved on the deltaic seafloor by analyzing the deposits preserved in 4 shallow cores. These have been collected by scuba diving at four different depths (10m, 20m, 30m and 40m) just in correspondence of the delta of the Entella river, in the Gulf of Tigullio (Western Ligurian Sea - Italy).</p><p>The Entella river runs through several onshore sites that can have been potential source of pollution or contamination of the marine system in the past and thus potentially preserved in the sedimentary sequence. Among those sites the possible contamination sources could be caused by extensive human activities such as production and processing of thermoplastic material, vegetable oils, junkyards, several quarries (limestone and slate), landfill of solid urban waste.</p><p>The core subsampling was directly performed onboard of the support vessel immediately after underwater collection. In total four cores, with a length comprised between 26 and 44 cm, have been collected. Each core was cut into 2-cm slices, which were then further divided in half.</p><p>The first half of sediment has been placed in a plastic bag in order to perform the followed analyses: granulometry, content of organic/inorganic matter by thermogravimetric method, XRPD analyses, C14 radiometric dating and chemical component analysis.</p><p>The second half of sediment, stored into a glass jar (to prevent plastic contamination), has been used to search for both agglutinated microplastics on picked agglutinated foraminifera and further microplastics on filters. Filters have been prepared using density separation in supersalty aqueous solution and filtration. Investigations have been performed by optical microscopy and µRaman spectroscopy. Since the analysis of the whole filter is extensively time-consuming, due to the high number of items present, we have tested a statistical approach to optimize the filter investigation.</p><p>All the data obtained were processed using the statistical software R. Multivariate analyses have been performed for the granulometry dataset as well as for other data. The results seem to point to specific trends characterized by possible seasonal fluctuations registered in the sedimentary sequence. The mineralogy dataset, investigated by cluster analysis, points to a clear separation of the mineralogical composition of the shallower versus the deeper cores. Interestingly, agglutinated foraminifera (i.e., mostly textulariids) seem to agglutinate large amount of carbon grains and plastics have been not yet observed.</p>

Early Silurian Benthic Foraminifera from Saudi Arabia - including the oldest known multichambered lituolids

ABSTRACT: A diverse assemblage of early Silurian agglutinated foraminifera is described from the transitional facies between the Qusaiba and Sharawra Formations of theQalibah Group of Saudi Arabia. The agglutinated foraminiferal assemblage consists of 73 species belonging to 24 genera, and is found in in dark graptolite-bearing claystone of Aeronian age. The assemblage is highly diverse compared with coeval early Silurian assemblages reported from Europe and North America. The assemblage is comprised mainly of species belonging to the monothalamid genera Saccammina, Psammosphaera, Lagenammina, Thurammina, Thuramminoides, Amphitremoida, Bathysiphon, Rhabdammina, and the tubothalamid genera Hyperammina, Tolypammina and Turritellella. The new species Thuramminoides ellipsoidalis n. sp. is described herein, but many of the species left in open nomenclature are also likely to be new. The assemblage also includes rare specimens belonging to the globothalamid (lituolid) genera Ammobaculites and Simobaculites. This new finding revises our understanding of the early evolution of the multichambered globothalamid foraminifera. Although the simple multichambered with rectilinear chamber arrangement are known from the Ordovician, our new findings show that the coiled globothalamids belonging to the order Lituolida are older than previously thought, and were already present in Gondwana by about 440 Ma.

Foraminiferal analysis and paleoenvironments of sediments in well -Aa, deepwater offshore, Niger Delta, Nigeria

Foraminiferal analysis was carried out on twenty five (25) ditch cutting samples from well -AA, offsore Niger Delta covering a depth interval of 9000ft-11025f. The study was aimed at age deduction, zoning the well, and interpreting the paleoenvironment of deposition. Lithostratigraphic description carried out on the sample revealed that the bulk lithofacies constitute shale with streaks of sand (fine-medium) between 9170ft - 9210ft and 9360ft -9380ft. The entire analysed interval was barren of planktonic foraminifera while depth 9960ft revealed a spot occurrence of Lagena spp,representing the only calcareous benthic foraminifera recovered in the entire interval. Few to common occurrences of deepwater agglutinated foraminifera were found in the well, dominated by some species of Haplophragmoides spp and Haplophragmoides narivaensis. Other foraminifera with rare and scattered occurrence includes, Cribrostomides spp, Bathysiphon spp, Troahammina spp, Cyclammina spp, Cyclammina cancellata, Valvulina spp, and Glomospira spp. The only microfaunal associated accessory recovered is ostracod at depth 1080ft. The analysed intervals was assigned a Middle – Late Miocene (N17 and older age) based on the FDO of Haplophragmoides narivaensis. The environment of deposition is based on the distribution of typical deep water arenaeceous foraminifera species recovered in the study. The predominance of the arenaeceous forms over calcareous forms suggest outer shelf environment of deposition. Keywords: Foraminifera, Palaeoenvironment, Niger delta, Biostratigraphy.

Benthic foraminifera distribution and diversity in inner and outer lagoonal sediments of the UAE (United Arab Emirates)

<p>Live and dead benthic foraminifera assemblages were studied from 50 samples collected in a lagoon located between Yas Island and Ras al Gurhab Island (UAE) in a system dominated by carbonate sedimentation.</p><p>Living and dead foraminifera tests are present at all of the sampled locations. The foraminifera assemblage is dominated by a high diversity of miliolidae together with epiphytic larger benthic foraminifera belonging to the genera Peneroplis, Spirolina and Sorites. Hyaline foraminifera, such as Ammonia and Elphidium, are commonly found at all the locations while agglutinated foraminifera are uncommon and have a scattered occurrence.</p><p>The abundance and diversity of benthic foraminifera were calculated for each sample. Four benthic foraminifera ecological indices were applied to the studied samples. For each of the samples we calculated: the total foraminiferal number (number of foraminifera in 1 g of sediment >125 μm); the percentages of agglutinated, porcellaneous and hyaline foraminifera tests; the ratio between living and dead benthic foraminifera; the ratio between larger benthic foraminifera with normal and abnormal test growth. The above-mentioned data have been applied to construct a foraminiferal assemblage database that facilitates the discrimination between inner and outer lagoonal environments.</p>

Correlative cathodoluminescence and EDS imaging of the benthic agglutinated foraminifer Liebusella goesi

<p>Sedimentary rocks, formed by the accumulation of mineral and organic particles, are important both for studies of the earth’s history as well as for being a source of fossil fuels. Over the course of the last decades, it has been demonstrated that scanning electron microscope (SEM)-based cathodoluminescence (CL) spectros­copy is a valuable technique for the characterisation of sedimentary rocks, complementary to other electron microscopy-based techniques, such as backscattered electron imaging (BSE/EBSD) and energy dispersive x-ray spectroscopy (EDS). Typically the CL yield is high enough for rapid scanning and, in some cases, even video-rate scanning, allowing fast in­spection of relatively large areas. It can be used to quantitatively map the quartz composition of the sample, for example, which enables the rigorous segmentation of granular and cemented material.</p><p>Textulariid benthic foraminifers live on and in seafloor sediments and form shells of agglutinated sediment particles. They are very important biostratigraphic markers, and fossil agglutinated foraminifera are important archives for paleoceanographic reconstructions. Furthermore, living textulariids show a strong diversity, populating  a diverse range of marine habitats partly and can reach high living abundances, making them important for benthic ecosystems.</p><p>In this work, we show how CL spectroscopy can be employed to study agglutinated foraminifera using the species Liebusella goesi from the Swedish Gullmar Fjord as an example. Fast panchromatic imaging using a photomultiplier tube was performed over a large area of the foraminifera, which revealed textures and contrasts of interest in the shell (test). A high resolution SEM image was acquired simultaneously to provide spatial context. Such a dataset can be valuable in establishing the geological history as well as in identifying the chemical composition of the cement used for the agglutination of sediment particles. Both the composition of the agglutinated particles and the chemical composition of the cement might bear valuable information about the environmental conditions, when the test was formed. EDS measurements were performed, revealing the spatial distribution of elements such as potassium, calcium, sodium, silicon and oxygen, in the sediment particles of the shell. This was useful in indicating the presence of minerals such as quartz and feldspar, and hyperspectral CL imaging was performed to rigorously identify them, and to visualize intragranular features, not visible in the EDS data. Based on the CL spectral data, we were further able to identify different grades/types of quartz and feldspars. These results show that these foraminifera prefer different sediment materials with varying grain sizes, depending on the size of the newly formed chamber, to achieve the highest mechanical stability.</p>

Mesocosm and Microcosm Experiments On the Feeding of Temperate Salt Marsh Foraminifera

Agglutinated foraminifera dominate in temperate salt marsh sediment, making them key indicators for monitoring sea level and environmental changes. Little is known about the biology of these benthic foraminifera because of difficulties in distinguishing live from dead specimens in laboratory cultures. We present data from 10 years of laboratory experiments using comparisons of the agglutinant trochamminids Trochammina inflata and Entzia macrescens and the miliolid Miliammina fusca with the calcareous rotalids Helenina anderseni and Elphidium williamsoni. Specimens were taken from a laboratory mesocosm representing Chezzetcook Inlet, a cool-temperate salt marsh in eastern Canada. We determined culture requirements for the agglutinated foraminifera in Petri dishes over 10–12 week periods. Five inexpensive, non-terminal ways of identifying live organisms were developed: spatial movement, detritus-gathering, attachment, clustering, and test opacity. Comparison with rose Bengal staining showed <10% diversion for calcareous species and T. inflata but M. fusca was over-counted by >30%. Terminal chambers of Trochammina inflata were examined by transmission electron microscopy to visualise food consumption and identify food in digestive vacuoles, both in specimens from mesocosm and in culture. Bacteria and unidentified detritus in the vacuoles establish that this agglutinated species is a saprophagous and bacterivorous detritivore. The adhesive secretions by these species apparently help them gather and possibly farm food while being relatively immobile in the sediments. Our observations of movement and feeding orientation in the agglutinants suggest links between form and function that underscore their value as ultra high resolution sea-level proxies. Mesocosm biomass and abundance counts show that foraminifera represent >50% of the meiofaunal biomass, emphasising their importance in the food web and energy-flow dynamics of temperate salt marsh systems.