Determination of the major constituents

Kremling, Klaus

doi:10.1002/9783527613984.ch11

Cited by 14 publications

(19 citation statements)

References 22 publications

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“…The Ca content of the seawater samples was determined with the EGTA complexometric titration method described by Kremling (1983). The colorless, free metal indicator GHA [glyoxal-bis(2-hydroxanil)] formed a deep red complex with Ca in seawater adjusted to pH 11.7 with a borate buffer prepared by dissolving 10 g of borax (NaZB407.H20) and 30 g of NaOH in 1 liter of distilled water.…”

Section: Co2 + Ho = Hc03mentioning

confidence: 99%

Validation of the alkalinity anomaly technique for investigating calcification of photosynthesis in coral reef communities

1991

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Experiments were conducted to establish the validity of the alkalinity anomaly technique for investigating rates of calcification and photosynthesis by coral reef‐building organisms. Rates of CaCO3 precipitation by whole colonies of the scleractinian coral Pocillopora damicornis (L.) were estimated under light and dark conditions with two different methods: complexometric titration of Ca with EGTA and acid titration of total alkalinity, with and without correction for alterations in the concentrations of ions other than carbonate species. The two techniques provided equivalent estimates of light‐enhanced and dark calcification, irrespective of whether corrections were applied to the total alkalinity data for changes in nutrient concentration. These results confirm that the assumptions of the alkalinity anomaly technique are fundamentally correct and that it is not necessary to correct total alkalinity data for changes in nutrient concentration because the corrections which apply are smaller than the variability observed in calcification data.

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Section: Co2 + Ho = Hc03mentioning

confidence: 99%

Validation of the alkalinity anomaly technique for investigating calcification of photosynthesis in coral reef communities

1991

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“…Alkalinity analyses were made aboard ship by potentiometric Gran titration (±0.02 meq L-I). Measurements of Ca 2 + and Mg 2 + were made by colorimetric titration (±0.2%; Kremling, 1983) for the titanium-syringe samples, and by inductively coupled plasma atomic emission spectroscopy (±3%) for the gas-tight samples.…”

Section: Methodsmentioning

confidence: 99%

CO2-depleted fluids from mid-ocean ridge-flank hydrothermal springs

Sansone

Mottl

Olson

et al. 1998

Geochimica et Cosmochimica Acta

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Abstract-Hydrothermal spring fluids were collected from Baby Bare, a basement outcrop on the sedimentcovered eastern flank of the Juan de Fuca Ridge overlying 3.5 Ma-old crust. These waters are venting at 25°C but have cooled from 64°C within the upper 200-300 m of the upflow zone during their ascent. Unlike ridge-axis hydrothermal vent fluids previously sampled, the total CO 2 content of the endmember spring fluids (0.85 Mmol kg-I) is depleted with respect to bottom seawater. The very low alkalinities (0.43 rneq L-I) and high Ca 2 + concentrations (55 mmol kg-I) of endmember spring fluids suggest that the removal of C in the spring fluids is associated with carbonate precipitation in the igneous basement. Assuming that 8-20% of the total ridge-flank heat loss rate of 50 X 10 18 cal yr-I (6.6 TW) is removed by porewater advecting from the sediment at 2:25°C (an upper limit dictated by the global input rate of Mg+ 2 to the oceans; Mottl and Wheat, 1994), a maximum global carbon sink of 1.0-2.6 X lOll mol yr-I ( 1.2-3.1 Mton-C yr-I ) and a maximum global alkalinity sink of 140-340 X 10 9 eq yr-I are calculated for warm (2:25°C) ridge-flank hydrothermal circulation. This carbon flux is only 2-5% of current estimates of subaerial and submarine volcanic CO 2 emissions (-50 X 1011 mol yr-I ), indicating that hydrothermal alteration of oceanic crust on young mid-ocean ridge flanks at temperatures of a few tens of degrees Celsius is only a relatively minor sink for carbon on a global basis. It is still possible, however, that ridge-flank alteration at lower temperatures «25°C) is an important component of the global carbon budget.

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“…& Martens, 1982). Sulphide was measured colorimetrically (Cline, 1969 (Kremling, 1983). Dissolved calcium and magnesium in MK samples were determined ( f 2%) with a Leeman Labs Plasmaspec-I inductively coupled plasma emission spectrometer; dissolved sodium was determined ( f 3%) by flame atomic absorption spectrometry (Perkin-Elmer 603).…”

Section: Methodsmentioning

confidence: 99%

Anaerobic diagenesis within Recent, Pleistocene, and Eocene marine carbonate frameworks

et al. 1990

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Porewaters from a variety of Recent, Pleistocene, and Eocene lithified marine carbonate frameworks displayed similar chemical characteristics: highly depleted concentrations of dissolved oxygen (>20 μM), elevated levels of dissolved methane (25‐5000 nM), and near‐seawater sulphate levels. These porewaters also had low pH values (7·5‐7·9), and contained elevated concentrations of sulphide (4–10 μM), dissolved inorganic carbon (2·05–2·46 mM), and inorganic nutrients. Hydrocarbon composition data indicate that the methane is biogenic, whereas the methane δ13C values (–47·4 ± 2·7%0) suggest that it has been subject to oxidation. The porewater dissolved inorganic carbon δ13C values varied from –0·6 to –39%0, suggesting input of carbon dioxide from organic matter oxidation. We conclude that anaerobic diagenesis involving bacterial degradation of organic matter is a common process in lithified marine carbonates and hypothesize that it may be an important factor controlling their carbonate geochemistry.

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Determination of the major constituents

Cited by 14 publications

References 22 publications

Validation of the alkalinity anomaly technique for investigating calcification of photosynthesis in coral reef communities

Validation of the alkalinity anomaly technique for investigating calcification of photosynthesis in coral reef communities

CO2-depleted fluids from mid-ocean ridge-flank hydrothermal springs

Anaerobic diagenesis within Recent, Pleistocene, and Eocene marine carbonate frameworks

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