scholarly journals A universal carbonate ion effect on stable oxygen isotope ratios in unicellular planktonic calcifying organisms

2011 ◽  
Vol 8 (4) ◽  
pp. 7575-7591
Author(s):  
P. Ziveri ◽  
S. Thoms ◽  
I. Probert ◽  
M. Geisen ◽  
G. Langer
Keyword(s):  
Oxygen Isotope ◽  
Laboratory Experiments ◽  
Planktonic Foraminifera ◽  
Seawater Temperature ◽  
Oxygen Isotopic Composition ◽  
Oxygen Isotope Fractionation ◽  
Oxygen Isotope Ratios ◽  
Extant Species ◽  
Oxygen Isotopic ◽  
New Biomarkers

Abstract. The oxygen isotopic composition (δ18O) of calcium carbonate of planktonic calcifying organisms is a key tool for reconstructing both past seawater temperature and salinity. The calibration of paloeceanographic proxies relies in general on empirical relationships derived from experiments on extant species. Laboratory experiments have more often than not revealed that variables other than the target parameter influence the proxy signal, which makes proxy calibration a challenging task. Understanding these secondary or "vital" effects is crucial for increasing proxy accuracy and possibly for developing new biomarkers. We present data from laboratory experiments showing that oxygen isotope fractionation during calcification in the coccolithophore Calcidiscus leptoporus and the calcareous dinoflagellate Thoracosphaera heimii is dependent on carbonate chemistry of seawater in addition to its dependence on temperature. A similar result has previously been reported for planktonic foraminifera, suggesting that the [CO32−] effect on δ18O is universal for unicellular calcifying planktonic organisms. The slopes of the δ18O/[CO32−] relationships range between −0.0243 (μmol kg−1)−1 (calcareous dinoflagellate T. heimii) and the previously published 0.0022 (μmol kg−1)−1 (non-symbiotic planktonic foramifera Orbulina universa), while C. leptoporus has a slope of 0.0048 (μmol kg−1)−1. We present a simple conceptual model, based on the contribution of δ18O-enriched HCO3− to the CO32− pool in the calcifying vesicle, which can explain the [CO32−] effect on δ18O for the different unicellular calcifiers. This approach provides a new insight into biological fractionation in calcifying organisms. The large range in δ18O/[CO32−] slopes should possibly be explored as a means for paleoreconstruction of surface [CO32−], particularly through comparison of the response in ecologically similar planktonic organisms.

scholarly journals A universal carbonate ion effect on stable oxygen isotope ratios in unicellular planktonic calcifying organisms

2012 ◽  
Vol 9 (3) ◽  
pp. 1025-1032 ◽  
Author(s):  
P. Ziveri ◽  
S. Thoms ◽  
I. Probert ◽  
M. Geisen ◽  
G. Langer
Keyword(s):  
Oxygen Isotope ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Planktonic Foraminifera ◽  
Seawater Temperature ◽  
Oxygen Isotopic Composition ◽  
Oxygen Isotope Fractionation ◽  
Oxygen Isotope Ratios ◽  
Extant Species ◽  
Oxygen Isotopic

Abstract. The oxygen isotopic composition (δ18O) of calcium carbonate of planktonic calcifying organisms is a key tool for reconstructing both past seawater temperature and salinity. The calibration of paloeceanographic proxies relies in general on empirical relationships derived from field experiments on extant species. Laboratory experiments have more often than not revealed that variables other than the target parameter influence the proxy signal, which makes proxy calibration a challenging task. Understanding these secondary or "vital" effects is crucial for increasing proxy accuracy. We present data from laboratory experiments showing that oxygen isotope fractionation during calcification in the coccolithophore Calcidiscus leptoporus and the calcareous dinoflagellate Thoracosphaera heimii is dependent on carbonate chemistry of seawater in addition to its dependence on temperature. A similar result has previously been reported for planktonic foraminifera, supporting the idea that the [CO32−] effect on δ18O is universal for unicellular calcifying planktonic organisms. The slopes of the δ18O/[CO32−] relationships range between –0.0243‰ (μmol kg−1)−1 (calcareous dinoflagellate T. heimii) and the previously published –0.0022‰ (μmol kg−1)−1 (non-symbiotic planktonic foramifera Orbulina universa), while C. leptoporus has a slope of –0.0048 ‰ (μmol kg−1)−1. We present a simple conceptual model, based on the contribution of δ18O-enriched HCO3− to the CO32− pool in the calcifying vesicle, which can explain the [CO32−] effect on δ18O for the different unicellular calcifiers. This approach provides a new insight into biological fractionation in calcifying organisms. The large range in δ18O/[CO32−] slopes should possibly be explored as a means for paleoreconstruction of surface [CO32−], particularly through comparison of the response in ecologically similar planktonic organisms.

Oxygen isotope fractionation between gypsum and its formation waters: Implications for past chemistry of the Kawah Ijen volcanic lake, Indonesia

2020 ◽  
Vol 105 (5) ◽  
pp. 756-763
Author(s):  
Sri Budhi Utami ◽  
Vincent J. van Hinsberg ◽  
Bassam Ghaleb ◽  
Arnold E. van Dijk
Keyword(s):  
Oxygen Isotope ◽  
Isotope Fractionation ◽  
Historical Record ◽  
Oxygen Isotopic Composition ◽  
Volcanic Lake ◽  
Oxygen Isotope Fractionation ◽  
Crater Lakes ◽  
Oxygen Isotopic ◽  
Fractionation Factors ◽  
Kawah Ijen

Abstract Gypsum (CaSO4·2H2O) provides an opportunity to obtain information from both the oxygen isotopic composition of the water and sulfate of its formation waters, where these components are commonly sourced from different reservoirs (e.g., meteoric vs. magmatic). Here, we present δ18O values for gypsum and parent spring waters fed by the Kawah Ijen crater lake in East Java, Indonesia, and from these natural samples derive gypsum-fluid oxygen isotope fractionation factors for water and sulfate group ions of 1.0027 ± 0.0003‰ and 0.999 ± 0.001‰, respectively. Applying these fractionation factors to a growth-zoned gypsum stalactite that records formation waters from 1980 to 2008 during a period of passive degassing, and gypsum cement extracted from the 1817 eruption tephra fall deposit, shows that these fluids were in water-sulfate oxygen isotopic equilibrium. However, the 1817 fluid was >5‰ lighter. This indicates that the 1817 pre-eruption lake was markedly different, and had either persisted for a much shorter duration or was more directly connected to the underlying magmatic-hydrothermal system. This exploratory study highlights the potential of gypsum to provide a historical record of both the δ18Owater and δ18Osulfate of its parental waters, and provides insights into the processes acting on volcanic crater lakes or any other environment that precipitates gypsum.

Oxygen isotope composition in Modiolus modiolus aragonite in the context of biological and crystallographic control

2008 ◽  
Vol 72 (2) ◽  
pp. 569-577 ◽  
Author(s):  
M. Cusack ◽  
D. Parkinson ◽  
A. Freer ◽  
A. Pérez-Huerta ◽  
A. E. Fallick ◽  
...  
Keyword(s):  
Biological Control ◽  
Oxygen Isotope ◽  
Environmental Influence ◽  
Isotope Composition ◽  
Seawater Temperature ◽  
Crystal Habit ◽  
Ambient Seawater ◽  
Oxygen Isotope Fractionation ◽  
Modiolus Modiolus ◽  
Horse Mussel

AbstractLiving systems exert exquisite control on all aspects of biomineral production and organic components, including proteins, are essential to this biological control. The protein-rich extrapallial (EP) fluid of bivalve molluscs is a strong candidate for the source of such proteins. Differences in calcium carbonate polymorphs between Modiolus modiolus and Mytilus edulis are concurrent with differences in EP fluid protein profiles. In conjunction with this biological control is the environmental influence which is interpreted using proxies such as δ18O to determine the history of ambient seawater temperature. In the horse mussel, Modiolus modiolus, the difference in oxygen isotope fractionation in the nacreous aragonite and the prismatic aragonite layer results in respective δ18O values of 2.1±0.2% and 2.5±0.2%. These δ18O values result in estimates of ambient seawater of 12.1±0.6°C and 10.2±0.6°C for nacreous and prismatic aragonite, respectively. Electron backscatter diffraction is used here to determine the crystallographic orientation at high spatial resolution, allowing the measurements of stable isotopes to be accurately mapped in terms of shell architecture. These preliminary data suggest that it is essential to account for both polymorph and crystal habit when deciphering ambient seawater temperature using δ18O as a proxy.

scholarly journals Nitrogen and oxygen isotopic constraints on the origin of atmospheric nitrate in coastal Antarctica

2007 ◽  
Vol 7 (8) ◽  
pp. 1925-1945 ◽  
Author(s):  
J. Savarino ◽  
J. Kaiser ◽  
S. Morin ◽  
D. M. Sigman ◽  
M. H. Thiemens
Keyword(s):  
Isotopic Composition ◽  
Oxygen Isotope ◽  
Transition Period ◽  
Isotope Effects ◽  
Isotope Ratios ◽  
Background Concentration ◽  
Night Time ◽  
Oxygen Isotope Ratios ◽  
Period 2 ◽  
Oxygen Isotopic

Abstract. Throughout the year 2001, aerosol samples were collected continuously for 10 to 15 days at the French Antarctic Station Dumont d'Urville (DDU) (66°40' S, l40°0' E, 40 m above mean sea level). The nitrogen and oxygen isotopic ratios of particulate nitrate at DDU exhibit seasonal variations that are among the most extreme observed for nitrate on Earth. In association with concentration measurements, the isotope ratios delineate four distinct periods, broadly consistent with previous studies on Antarctic coastal areas. During austral autumn and early winter (March to mid-July), nitrate concentrations attain a minimum between 10 and 30 ng m−3 (referred to as Period 2). Two local maxima in August (55 ng m−3) and November/December (165 ng m−3) are used to assign Period 3 (mid-July to September) and Period 4 (October to December). Period 1 (January to March) is a transition period between the maximum concentration of Period 4 and the background concentration of Period 2. These seasonal changes are reflected in changes of the nitrogen and oxygen isotope ratios. During Period 2, which is characterized by background concentrations, the isotope ratios are in the range of previous measurements at mid-latitudes: δ18Ovsmow=(77.2±8.6)‰; Δ17O=(29.8±4.4)‰; δ15Nair=(−4.4±5.4)‰ (mean ± one standard deviation). Period 3 is accompanied by a significant increase of the oxygen isotope ratios and a small increase of the nitrogen isotope ratio to δ18Ovsmow=(98.8±13.9)‰; Δ17O=(38.8±4.7)‰ and δ15Nair=(4.3±8.20‰). Period 4 is characterized by a minimum 15N/14N ratio, only matched by one prior study of Antarctic aerosols, and oxygen isotope ratios similar to Period 2: δ18Ovsmow=(77.2±7.7)‰; Δ17O=(31.1±3.2)‰; δ15Nair=(−32.7±8.4)‰. Finally, during Period 1, isotope ratios reach minimum values for oxygen and intermediate values for nitrogen: δ18Ovsmow=63.2±2.5‰; Δ17O=24.0±1.1‰; δ15Nair=−17.9±4.0‰). Based on the measured isotopic composition, known atmospheric transport patterns and the current understanding of kinetics and isotope effects of relevant atmospheric chemical processes, we suggest that elevated tropospheric nitrate levels during Period 3 are most likely the result of nitrate sedimentation from polar stratospheric clouds (PSCs), whereas elevated nitrate levels during Period 4 are likely to result from snow re-emission of nitrogen oxide species. We are unable to attribute the source of the nitrate during periods 1 and 2 to local production or long-range transport, but note that the oxygen isotopic composition is in agreement with day and night time nitrate chemistry driven by the diurnal solar cycle. A precise quantification is difficult, due to our insufficient knowledge of isotope fractionation during the reactions leading to nitrate formation, among other reasons.

The oxygen isotope stratigraphic record of the Late Pleistocene

1977 ◽  
Vol 280 (972) ◽  
pp. 169-182 ◽  
Keyword(s):  
Isotopic Composition ◽  
Oxygen Isotope ◽  
Late Pleistocene ◽  
World Ocean ◽  
Oxygen Isotopic Composition ◽  
Stratigraphic Correlation ◽  
Equatorial Atlantic ◽  
Deep Sea Sediment ◽  
Oxygen Isotopic ◽  
Isotope Measurements

Oxygen isotope measurements have been made in foraminifera from over 60 deep-sea sediment cores. Taken together with the oxygen isotope measurements published by Emiliani from Caribbean and Equatorial Atlantic cores, this comprises a unique body of stratigraphic data covering most of the important areas of calcareous sediment over the whole world ocean. The oxygen isotopic composition of foraminifera from cores of Late Pleistocene sediment varies in a similar manner in nearly all areas; the variations reflect changes in the oxygen isotopic composition of the ocean. The oceans are mixed in about 1 ka so that ocean isotopic changes, resulting from fluctuations in the quantity of ice stored on the continents, must have occurred almost synchronously in all regions. Thus the oxygen isotope record provides an excellent means of stratigraphic correlation. Cores accumulated at rates of over about 5 cm/ka provide records of oxygen isotopic composition change that are almost unaffected by post-depositional mixing of the sediment. Thus they preserve a detailed record of the advance and retreat of the ice masses in the northern hemisphere, and provide a unique source of information for the study of ice-sheet dynamics.

Paleobiological and isotopic studies of eggshells from a declining dinosaur species

Paleobiology ◽  
1979 ◽  
Vol 5 (4) ◽  
pp. 380-414 ◽  
Author(s):  
H. K. Erben ◽  
J. Hoefs ◽  
K. H. Wedepohl
Keyword(s):  
Isotopic Composition ◽  
Oxygen Isotopic Composition ◽  
Humid Climate ◽  
Physiological Mechanisms ◽  
Extant Species ◽  
Isotopic Studies ◽  
Spanish Pyrenees ◽  
Frequent Absence ◽  
Oxygen Isotopic ◽  
The Mean

Late Cretaceous dinosaur eggshells from southern France and the Spanish Pyrenees, presumably belonging to the sauropodHypselosaurus priscusMatheron, are almost exclusively composed of primary calcite. Besides normal development of these eggshells, there appear two kinds of pathologic tendencies: bi- or multi-shells (infrequent), and shells with a reduced thickness (increasing in frequency until, in the uppermost horizon, they represent more than 90% of the sample). The extinction of the species is attributed primarily to the consequences of thinning of the eggshells.The physiological mechanisms producing pathologic dinosaur eggshells are evaluated in the light of homologous phenomena occurring in living birds and reptiles. On this basis, it is concluded that in the late Maastrichtian populations of“Hypselosaurus,”pathologic eggshells were caused by hormonal imbalances of the vasotocin and of the estrogen levels. On the same basis it is postulated that the teratological shell repetition led to embryo suffocation and that the pathological reduction in shell thickness caused shell breakage and dehydration of the embryo. The lethal results are evident from the frequent absence of “resorption craters” in the mammillary knobs of pathologic shells, a fact which indicates either lack of fertilization of the eggs or the perishing of the embryo prior to the calcification of its skeletal bones. A change in environmental conditions is the ultimate factor which caused hormonal imbalances and extinction. Such a change is indicated by a shift of the mean oxygen isotopic composition (δ18O) of eggshell carbonates from −0.6%oto −5.3%o, and by changes in Sr. Information of palaeo-climate is primarily derived from eggshells of living birds and reptiles. The correlation between temperature and oxygen isotopic composition of waters (and related carbonates) is less distinct than for marine carbonates. δ13C ranges from −16.5 to −4.5 of eggshells of extant species indicate food from “normal” C3metabolism and from C4metabolism of plants in a dry climate.“Hypselosaurus”populations probably consumed “normal” C3plants. Using isotopic calibration of eggshell carbonates for the interpretation of δ13C and δ18O values of dinosaur eggshells, a slight change from higher to lower temperatures or a change from a dry to a more humid climate during the time from Lower (and Middle) to Late Maastrichtian can be assumed. The latter explanation is favored because the exceptionally high Sr in the Early Maastrichtian eggshells could be a potential indicator of co-existing evaporites.

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