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  • 1
    Online Resource
    Online Resource
    Benthic foraminifera as bioindicator for cold-water coral reef ecosystems along the Irish margin (2009)
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    In: Deep-sea research. Part 1, Oceanographic research papers, Amsterdam [u.a.] : Elsevier Science, 1993, 56(2009), 12, Seite 2216-2234, 1879-0119
    In: volume:56
    In: year:2009
    In: number:12
    In: pages:2216-2234
    Description / Table of Contents: Cold-water coral ecosystems building cold-water carbonate mounds occur worldwide and are especially developed along the European margin, from northern Norway to the Gulf of Cadiz. A remarkable mound province is documented southwest of Ireland along the Porcupine and Rockall Banks. In this area carbonate mounds are formed in water depths between 500 and 1200 m and are often densely settled by cold-water coral ecosystems offering many ecological niches for benthic foraminifera. We investigated total (unstained) benthic foraminiferal assemblages from surface sediments (0-1 cm, 〉63 Mym size fraction) of this region with the aim to trace their distribution patterns and to test if they can be used as bioindicators for facies characterization in different parts of carbonate mound systems. Our quantitative data were further statistically treated with non-metric multidimensional scaling (nMDS) based on BrayCurtis similarity matrix to highlight community patterns that were not readily apparent. Our results indicate that different benthic foraminiferal assemblages characterize different facies along cold-water carbonate mounds and are related to the environmental conditions and available substrates. The following facies can be described: (1) the Off-Mound Facies is dominated by uvigerinids and other infaunal species; (2) the Dropstone Facies is characterized by infaunal Globocassidulina subglobosa and attached-epifaunal Cibicidoides sp.; (3) the Dead Coral Facies is characterised by epifaunal species (e.g., Planulina ariminensis, Hanzawaia boueana) and infaunal species (Spiroplectinella wrightii, Angulogerina angulosa, Epistominella vitrea); (4) the Living Coral Facies includes both infaunal and epifaunal species, but is dominated by the epifaunal Discanomalina coronata; and (5) the Sandwave Facies contains high abundances of epifaunal species including D. coronata. Based on this distribution, we propose D. coronata, as an indicator species to identify active mounds and/or living cold-water coral ecosystems. Our results also emphasise the importance of studying the small size fractions that yield many infaunal species. A causal link exists between distribution patterns of benthic foraminifera and cold-water coral facies, thus providing an independent tool to identify and describe the different facies in this setting.
    Type of Medium: Online Resource
    Pages: Ill., graph. Darst
    ISSN: 1879-0119
    DOI: 10.1016/j.dsr.2009.07.009
    Language: English
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  • 2
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    Origin and age of carbonate clasts from the Lusi eruption, Java, Indonesia (2018)
    Elsevier
    In:  Marine and Petroleum Geology, 90 . pp. 138-148.
    Details
    Publication Date: 2021-02-08
    Description: Deep stratigraphic constrains below the Indonesian Lusi mud eruption are currently lacking due to the absence of deep wells and good quality seismic data. A collection of carbonate clasts has been sampled from the Lusi site, active since its birth in 2006. These specimens are part of a large variety of lithotypes erupted from the main crater. The carbonates analysed comprise scleractinian coral and bivalve shell fragments, probably shallow-water in origin, and clasts consisting of planktonic foraminifera-bearing mudstone, from pelagic deposits. Selected rocks were analysed using planktonic foraminifera and 87Sr/86Sr dating with the aim to constrain their age and to improve the understanding of the, so far unknown, sequence of limestone deposits inferred at this site. Based on biostratigraphy using planktonic foraminifera, one group of samples reveal to belong to the Planktonic Foraminifera Zone M5b, with an age comprised between 16.29 and 15.10 Ma (Miocene, Latest Burdighalian to Langhian). The Sr isotope-based ages of clasts analysed for 87Sr/86Sr cover a larger time window spanning from Pliocene (Zanclean and Piacenzian), Miocene (Messinian) down to Eocene (Priabonian). The Pliocene and Messinian ages are unreasonably young from what is known of the local geology and one sample provided an 87Sr/86Sr age that is ∼8 My younger compared to that obtained from the planktonic foraminifera assemblage occurring in that sample. The discrepancy suggests that this and the other unduly young samples have possibly been contaminated by geological materials with radiogenic Sr isotope composition. The minimum age of 37.18 Ma obtained by 87Sr/86Sr from a well-preserved oyster shell indicates that some of the clasts can be attributed to the deep seated Ngimbang Formation. The dating has been combined with the interpretation of seismic profiles to investigate the stratigraphy of inferred carbonates below Lusi and the PRG-1 well located some kilometres to the north east. PRG-1 borehole data are also integrated and discussed in this study. The obtained results reveal multiple implications: a) the Tuban and Kujung Formations are overlapping at Lusi site; b) the Lusi feeder conduit brecciated and mobilized to the surface carbonate lithologies buried as deep as possibly ∼3.8 km as well as even older and deeper seated lithotypes from the Ngimbang Formation; c) since the deeper carbonate samples erupted in 2006 belong to the typically not overpressured Kujung Formation, an additional overpressure generated from deeper units (Ngimbang Formation) would be required to force these fragments to surface.
    Type: Article , PeerReviewed , info:eu-repo/semantics/article
    Format: text
    DOI: 10.1016/j.marpetgeo.2017.11.012
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  • 3
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    Late Weichselian deglaciation and early Holocene development of a cold-water coral reef along the Lopphavet shelf (Northern Norway) recorded by benthic foraminifera and ostracoda (2014)
    Elsevier
    In:  Deep Sea Research Part II: Topical Studies in Oceanography, 99 . pp. 249-269.
    Details
    Publication Date: 2020-08-05
    Description: Cold-water coral (CWC) settlement in northern Norway is strongly related to the outlet-glaciers of the Fennoscandian Ice-sheet, and dating of known CWC structures show clearly post-glacial ages. Two gravity cores (POS391 559/2,277 cm long and POS391 559/3,282 cm long) were recovered on a CWC reef in the area of Lopphavet, northern Norway. Detailed investigations on lithology (sediment structures and composition), micropaleontology (foraminifera and ostracoda) and AMS 14C dating on the epibenthic foraminifera Discanomalina coronata were performed on the two cores. Phosphorus analyses were performed only on core POS391 559/3. Results indicate that the whole core POS391 559/2 is representative of a CWC reef environment. The base of the core is dated at 10,600±120 cal. yr BP, thus representing one of the oldest ages of a Norwegian coral reef. Core POS391 559/3 documents the passage from a proximal glacier environment characterized by fine silty sediments with intercalation of several dropstone layers to a CWC ecosystem. The transition from the glacial to the interglacial stage is dated as old as 10,725±205 cal. yr BP, whereas the base of the core is dated to an age of 15,300±550 cal. yr BP. Diversity of benthic foraminifera is higher within the CWC, especially in the intervals containing coral framework. Five clusters are identified based on the Bray–Curtis Similarity Term Analyses and the interpretation of data shows that they are related to different ecological settings, e.g., fluctuations of the sea-ice cover; influence of the warmer and more saline Atlantic water masses; transitional to a fully interglacial environment; well oxygenated, nutrient-rich and high current setting being conducive to CWC. Ostracod assemblages show that these crustaceans may be also used to characterize sedimentary facies on CWC reefs.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1016/j.dsr2.2013.07.009
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  • 4
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    The FOBIMO (FOraminiferal BIo-MOnitoring) initiative—Towards a standardised protocol for soft-bottom benthic foraminiferal monitoring studies (2012)
    Elsevier
    In:  Marine Micropaleontology, 94/95 . pp. 1-13.
    Details
    Publication Date: 2020-10-16
    Description: The European Community Marine Strategy Framework Directive (MSFD) was established to provide guidelines for monitoring the quality of marine ecosystems. Monitoring the status of marine environments is traditionally based on macrofauna surveys, for which standardised methods have been established. Benthic foraminifera are also good indicators of environmental status because of their fast turnover rates, high degree of specialisation, and the preservation of dead assemblages in the fossil record. In spite of the growing interest in foraminiferal bio-monitoring during the last decades, no standardised methodology has been proposed until today. The aim of the FOraminiferal BIo-MOnitoring (FOBIMO) expert workshop, held in June 2011 at Fribourg, Switzerland, which assembled 37 scientists from 24 research groups and 13 countries, was to develop a suite of standard methods. This paper presents the main outcome of the workshop, a list of motivated recommendations with respect to sampling devices, sample storage, treatment, faunal analysis and documentation. Our recommendations fulfil the criteria imposed both by scientific rigour and by the practical limitations of routine studies. Hence, our aim is to standardise methodologies used in bio-monitoring only and not to limit the use of different methods in pure scientific studies. Unless otherwise stated, all recommendations concern living (stained) benthic foraminiferal assemblages. We have chosen to propose two types of recommendations. Mandatory recommendations have to be followed if a study wants to qualify as sound and compatible to the norms. The most important of these recommendations are the interval from 0 to 1 cm below the sediment surface has to be sampled, and an interface corer or box corer that keeps the sediment surface intact is to be used for offshore surveys. A grab sampler must not be deployed in soft sediments. Three replicate samples are to be taken and analysed separately. Samples are to be washed on a 63-mu m screen, and the living benthic foraminiferal fauna of the 〉 125 mu m fraction is to be analysed. Splits are to be picked and counted entirely, and all counted foraminifera from at least one replicate per station have to be stored in micropalaeontological slides. Census data, supplementary laboratory data and microslides have to be archived. Advisory recommendations are to sample in autumn, to have a sample size of 50 cm(2) or a tube of 8 cm inner diameter, to use 〉 70% ethanol as a preservative, rose Bengal at a concentration of 2 grams per litre for staining, and a staining time of at least 14 days. The split size should be defined by a target value of 300 specimens, heavy liquid separation should be avoided, and the 63-125 mu m fraction or deeper sediment levels may be considered in some environments. We are convinced that the application of this protocol by a large number of scientists is a necessary first step to a general acceptance of benthic foraminifera as a reliable tool in bio-monitoring studies
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1016/j.marmicro.2012.06.001
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  • 5
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    The Helgoland Experiment - assessing the influence of methodologies on Recent benthic foraminiferal assemblage composition (2012)
    In:  [Poster] In: The Micropalaeontological Society's Foraminifera and Nannofossil Groups Joint Meeting, 21.-22.06.2012, Edinburgh, Great Britain .
    Details
    Publication Date: 2012-07-31
    Description: Most recent benthic foraminiferal studies focus on species inventory and distribution and ecology. An integration of results from different studies is often hampered by the application of different methods. The influence of different sample treatments and analyses on the accuracy of faunal data is the subject of the present study. We compare preservation, staining, and preparation techniques to constrain the internal data variability as inferred by different methodologies. Variations produced by different persons analysing the same foraminiferal assemblage and consequences for the accuracy of foraminiferal data are addressed. We retrieved a large surface sediment sample from the southeastern North Sea near Helgoland. Twelve replicate subsamples were taken and preserved with ethanol, ethanol - rose Bengal solution, or formaldehyde. Samples were then processed with standard methods. Some samples were stained after processing with an aqueous rose Bengal solution, or the foraminifera were concentrated by floatation. Coloration of specimens that were living at the time of sampling was different between samples where rose Bengal was added together with the ethanol and samples, which were stained after washing. In the latter case, only the last two or three chambers were impregnated. The sample preserved with formaldehyde showed dissolution features affecting both arenaceous and calcareous species. In particular, the outer shell layer of miliolids was corroded, calcareous cement of agglutinated tests was reduced, and pores of rotalids were enlarged. The population density reflecting the number of recognised, stained specimens was highly variable among different preservation, picking modes, and examinators. The accuracy of picking was in the range of ±4 % (1-sigma), while the reproducibility ranged from -44 to +26 % between different examinators, which also concerns the proportions of dominant species. There was no significant difference between wet and dry picking within the 95 % confidence limits, but samples that were stained later or concentrated by floatation generally yielded a lower number of specimens. Arenaceous species and miliolids were underrepresented in samples that were stained after washing and in the floatation concentrate while Stainforthia fusiformis was seemingly better recognised therein. More data and parallel investigations involving a larger number of specialists are needed to achieve a better comparability of faunal census data.
    Type: Conference or Workshop Item , NonPeerReviewed
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  • 6
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    The carbonate deposits underneath the geysering Lusi eruption (Java, Indonesia) (2017)
    In:  [Talk] In: EGU General Assembly 2017, 23.-28.04.2017, Vienna, Austria .
    Details
    Publication Date: 2018-05-28
    Type: Conference or Workshop Item , NonPeerReviewed
    Format: text
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  • 7
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    Bolboforma — an overview (2005)
    Springer
    Details
    Publication Date: 2022-03-10
    Description: A summary of the present knowledge of Bolboforma is presented in this paper. The genus Bolboforma contains a diverse group of marine, mostly single-chambered enigmatic microfossils (phytoplankton, possibly Chrysophyta) which produced calcitic monocrystalline spheroidal tests with or without inner cysts and with various types of ornamentation. The genus Bolboforma occurs in the time interval between late Early Eocene to Late Pliocene, at middle and higher latitudes, and thus, has not been recorded in Quaternary to Recent Sediments. The genus is represented globally, but the first and the last occurrence of the genus appear to be spatially diachronous in both hemispheres. Bolboforma started in the southern hemisphere at the Campbell Plateau (SW Pazific) during the Early Eocene approximately 53 Ma ago, and the genus lived there until latest Miocene times (5.3 Ma at the Kerguelen Plateau, Southern Indian Ocean). The first occurrence of Bolboforma in the northern hemisphere is observed in Upper Eocene Sediments (ca. 36.5 Ma) in the Labrador Sea (North Atlantic), and its youngest occurrence is observed in the Hatton-Rockall Basin (North Atlantic) in the Late Pliocene at 2.84 Ma. Well established and common species permit the definition of nineteen Bolboforma zones/subzones. Not all of these are observed in both hemispheres. In the southern hemisphere all four Paleogene zones, but only eight Neogene zones are present, in the northern hemisphere only one Paleogene zone, but fourteen Neogene zones have been determined. Bolboforma distribution, which appears to be broadly bipolar in temperate to cool regions at middle to higher latitudes, aso seems to be linked to the evolution of surface watermasses and their boundaries.
    Type: Article , PeerReviewed
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  • 8
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    Biometry and taxonomy of Adriatic Ammonia species from Bellaria–Igea Marina (Italy) (2021)
    Copernicus Publications (EGU)
    Details
    Publication Date: 2024-02-07
    Description: LivingAmmoniaspecies and an inventory of dead assemblages from Adriatic subtidal, nearshoreenvironments were investigated at four stations off Bellaria, Italy.Ammonia falsobeccarii, Ammonia parkinso-niana, Ammonia tepida, andAmmonia venetawere recognized in the living (rose-bengal-stained) fauna, andAmmonia bellarian. sp. is described herein for the first time.Ammonia beccariiwas only found in the deadassemblage. The biometry of 368 living individuals was analysed by using light microscopic and scanning elec-tron microscopic images of three aspects. A total of 15 numerical and 8 qualitative parameters were measuredand assessed, 5 of which were recognized to be prone to a certain subjectivity of the observer. The accuracy ofnumerical data as revealed by the mean residuals of parallel measurements by different observers ranged from0.5 % to 5.5 %. The results indicated a high degree of intraspecific variability. The test sizes of the individualspecies were log-normally distributed and varied among the stations. Parameters not related to the growth ofthe individuals, i.e. flatness of the tests, dimensions of the second-youngest chamber, proloculus, umbilical andpore diameter, sinistral–dextral coiling, and umbilical boss size, were recognized as being species-distinctive incombination. They may well supplement qualitative criteria that were commonly used for species discriminationsuch as a lobate outline, a subacute or rounded peripheral margin, or the degree of ornamentation on the spiraland umbilical sides. The averages of the measured parameters were often lower than the range of previouslypublished values, mainly because the latter were retrieved from a few adult specimens and not from the wholeassemblage as in the present approach. We conclude that the unprecedented high proportions ofAmmonia bec-cariiin the northern Adriatic may well be artificial. A robust species identification without genetic analyses ispossible by considering designated biometric parameters. This approach is also applicable to earlier literaturedata, and their re-assessment is critical for a correct denomination of recent genotypes.
    Type: Article , PeerReviewed
    Format: archive
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  • 9
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    Assessing the impact of diagenesis on foraminiferal geochemistry from a low latitude, shallow-water drift deposit (2020)
    Elsevier
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    Publication Date: 2024-03-21
    Description: Due to their large heat and moisture storage capabilities, the tropics are fundamental in modulating both regional and global climate. Furthermore, their thermal response during past extreme warming periods, such as super interglacials, is not fully resolved. In this regard, we present high-resolution (analytical) foraminiferal geochemical (δ18O and Mg/Ca) records for the last 1800 kyr from the shallow (487 m) Inner Sea drift deposits of the Maldives archipelago in the equatorial Indian Ocean. Considering the diagenetic susceptibility of these proxies, in carbonate-rich environments, we assess the integrity of a suite of commonly used planktonic and benthic foraminifera geochemical datasets (Globigerinoides ruber (white), Globigerinita glutinata (with bulla), Pulleniatina obliquiloculata (with cortex) and Cibicides mabahethi) and their use for future paleoceanographic reconstructions. Using a combination of spot Secondary Ion Mass Spectrometer, Electron Probe Micro-Analyzer and Scanning Electron Microscope image data, it is evident that authigenic overgrowths are present on both the external and internal test (shell) surfaces, yet the degree down-core as well as the associated bias is shown to be variable across the investigated species and proxies. Given the elevated authigenic overgrowth Mg/Ca (∼12–22 mmol/mol) and δ18O values (closer to the benthic isotopic compositions) the whole-test planktonic G. ruber (w) geochemical records are notably impacted beyond ∼627.4 ka (24.7 mcd). Yet, considering the setting (i.e. bottom water location) for overgrowth formation, the benthic foraminifera δ18O record is markedly less impacted with only minor diagenetic bias beyond ∼790.0 ka (28.7 mcd). Even though only the top of the G. ruber (w) and C. mabahethi records (whole-test data) would be suitable for paleo-reconstructions of absolute values (i.e. sea surface temperature, salinity, seawater δ18O), the long-term cycles, while dampened, appear to be preserved. Furthermore, planktonic species with thicker-tests (i.e. P. obliquiloculata (w/c)) might be better suited, in comparison to thinner-test counter-parts (i.e. G. glutinata (w/b), G. ruber (w)), for traditional whole-test geochemical studies in shallow, carbonate-rich environments. A thicker test equates to a smaller overall bias from the authigenic overgrowth. Overall, if the diagenetic impact is constrained, as done in this study, these types of diagenetically altered geochemical records can still significantly contribute to studies relating to past tropical seawater temperatures, latitudinal scale ocean current shifts and South Asian Monsoon dynamics
    Type: Article , PeerReviewed
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  • 10
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    Monsoon and Tropical Climate Forcing on the Physicochemical and Thermocline Characteristics of the Maldives Inner Sea: Insights From Marine Isotope Stages 1–2 and 10–13 (2021)
    Wiley-Blackwell STM
    Details
    Publication Date: 2024-03-21
    Description: The Maldivian archipelago, in the equatorial Indian Ocean, provides a unique location to assess long‐term basin‐wide South Asian Monsoon (SAM) processes as well as its response during climatic extremes. This insight is beneficial to better understand future SAM influences on the Maldives Inner Sea physicochemical characteristics and its diverse tropical ecosystems in a warming world. This study uses samples from International Ocean Discovery Program Expedition 359, drilled within the Inner Sea drift deposits. Multiple foraminiferal species ( n = 15) and proxies (δ 18 O, δ 13 C, and Mg/Ca) are used to assess glacial‐interglacial SAM dynamics influencing the Inner Sea conditions across Marine Isotope Stages (MIS) 1–2 and 10–13. The summer SAM is modulated by insolation and atmospheric CO 2 and has a predominant impact on the northern Indian Ocean surface salinity. As with present‐day observations, a strong summer monsoon resulted in large basin‐wide δ 18 O sw (salinity) gradients during the interglacials. Moreover, at the MIS11 minimum (MIS11c), a recognized analog for the present‐day, sea surface temperatures (SSTs) were warmer than the present with a stronger summer SAM. This led to an expanded surface mixed layer and strong thermocline, resulting in a highly stratified water column and prominent oxygen minimum zone in the Inner Sea during MIS11c. SSTs in the Maldives are projected to increase at the end of this century and based on the reality that current warming (anthropogenically driven) is much faster than seen during MIS11, the Maldivian tropical coral reef and benthic shoal ecosystems will be subject to increasing stress.
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