Calcite and aragonite precipitation from seawater solutions of various salinities: Precipitation rates and overgrowth compositions

Zhong, Sheng; Mucci, Alfonso

doi:10.1016/0009-2541(89)90064-8

Cited by 230 publications

(167 citation statements)

References 49 publications

Supporting

Mentioning

149

Contrasting

Unclassified

Order By: Relevance

“…Lines in the figure are listed in Table 2). Lines in the figure are listed in Zhong and Mucci (1989). They demonstrated the following empirical equation on inorganic CaCO 3 precipitation from seawater:…”

Section: Resultsmentioning

confidence: 99%

Effect of CaCO3 (aragonite) saturation state of seawater on calcification of Porites coral

Ohde

Hossain

2004

Geochem. J.

View full text Add to dashboard Cite

Using living corals collected from Okinawan coral reefs, laboratory experiments were performed to investigate the relationship between coral calcification and aragonite saturation state (W) of seawater at 25∞C. Calcification rate of a massive coral Porites lutea cultured in a beaker showed a linear increase with increasing W aragonite values (1.08-7.77) of seawater. The increasing trend of calcification rate (c) for W is expressed as an equation, c = aW + b (a, b: constants). When W was larger than ~4, the coral samples calcified during nighttime, indicating an evidence of dark calcification. This study strongly suggests that calcification of Porites lutea depends on W of ambient seawater. A decrease in saturation state of seawater due to increased pCO 2 may decrease reef-building capacity of corals through reducing calcification rate of corals.Keywords: coral, calcification, aragonite, saturation state, cultured experiment As a result of coral calcification (Eq. (2)), the W aragonite of seawater is altered through releasing CO 2 in surrounding environments. The elevated CO 2 in marine environments lowers pH through decreasing CO 3 2-concentration and leads to a decrease in W of seawater.The relationship between coral-reef calcification and W of seawater has been reported through field observations. Broecker and Takahashi (1966) observed that precipitation rate of CaCO 3 on the Bahama Bank was proportional to the degree of supersaturation, as a secondorder reaction. Smith and Pesret (1974) pointed out that coral calcification in the lagoon of Fanning Island was affected by the carbonate mineral saturation state. On a coral reef flat of Okinawa, Ohde and van Woesik (1999) also observed that calcification rate increased with the increase in W aragonite of seawater during daytime. From a global viewpoint associated with atmospheric CO 2 budget, Kleypas et al. (1999) strongly pointed out that coral calcification responds to W of seawater.On the other hand, the relationship between coral calcification and W aragonite of seawater was also studied through laboratory experiments under controlled conditions. Gattuso et al. (1998) observed a nonlinear increase in calcification rate of Stylophora pistillata with increasing W of seawater with a plateau in the rate when saturation state was larger than 3.90. Marubini and Atkinson (1999) also observed that calcification rate of Porites compressa decreased with decreasing W aragonite of seawater. However, only a few studies have provided clear relationship between coral calcification and seawater W.In order to elucidate the relationship between coral

show abstract

Section: Resultsmentioning

confidence: 99%

Effect of CaCO3 (aragonite) saturation state of seawater on calcification of Porites coral

Ohde

Hossain

2004

Geochem. J.

View full text Add to dashboard Cite

show abstract

“…Making use of the data presented by Zhong and Mucci [1989], we further note that the retardation of calcite precipitation by impurities is most significant at relatively low driving forces for precipitation (saturation ratio <2.6). In our experiments, the driving force for IPS is related to the effective stress and the compaction strain.…”

Section: Effects Of Sample Impuritiesmentioning

confidence: 90%

Compaction creep of wet granular calcite by pressure solution at 28°C to 150°C

2010

View full text Add to dashboard Cite

[1] Uniaxial compaction experiments have been carried out on wet calcite powders prepared from milled limestone, analytical grade calcite, and superpure calcite. The tests were performed at 28°C-150°C, effective stresses of 20-47 MPa, and a pore pressure of 20 MPa, using presaturated CaCO 3 solution as the pore fluid. Sample grain sizes ranged from 12 to 86 mm. The aim was to determine if creep occurs by intergranular pressure solution (IPS) under these conditions and to identify the rate-controlling process. The wet samples showed significant creep, while dry and oil-flooded samples did not. Wet samples were also characterized by microstructures such as sutured grain contacts, grain indentations, and overgrowths, suggesting the operation of IPS. The behavior of the wet samples at low strains (<4-5%) agreed well with the predictions of standard models for diffusion-controlled pressure solution. However, at higher strains (5-10%), creep slowed down compared with the model predictions. Transient flow-through tests performed in this regime led to an acceleration of creep, consistent with models for precipitation-controlled IPS, and demonstrated an increase in the impurity content of the pore fluid toward higher strains. Since some of these impurities (notably Mg 2+ ) retard precipitation in calcite, we suggest that creep occurred by diffusion-controlled IPS at low strain, giving way to precipitation control at larger strains as impurities accumulated. Fitting of the diffusion-controlled IPS model to the low strain data yielded values of the grain boundary diffusion product DS in calcite of ∼10 −19 m 3 s −1 at 150°C.

show abstract

“…Although the P CO2 in the present experiments fluctuated somewhat through daily atmospheric change and human respiration in the room, the P CO2 in our method can be regulated by using artificial CO 2 -N 2 gas mixture as has been used by the previous investigators (e.g., Zhong and Mucci, 1989).…”

Section: Technical Featuresmentioning

confidence: 90%

A new method for the study of trace element partitioning between calcium carbonate and aqueous solution: A test case for Sr and Ba incorporation into calcite

Terakado

Taniguchi

2006

Geochem. J.

View full text Add to dashboard Cite

A new experimental method (evaporation method) for calcium carbonate precipitation in aqueous solution was attempted in order to develop a convenient and controllable experimental technique for obtaining precise trace element partition coefficients. Calcite crystals were formed by evaporation of H 2 O from the aqueous mother solution using a dehumidifier, and the consumed Ca ions were supplied from a refill solution to maintain supersaturation. This method has been tested for Sr and Ba partition coefficients using NaCl (3.5%) solution under room temperature and pressure. The results of two runs give Sr partition coefficients of 0.0585 and 0.0546, and Ba partition coefficients of 0.0302 and 0.0275 for growth rates of 152 and 499 µmol·m -2 ·hr -1 , respectively. It was found that this method has several merits for partitioning experiments: (1) pH of the solution is close to the natural ones, for example, pH of 8.08 in the present case is close to that of seawater; (2) chemical composition of the mother solution can be chosen to imitate natural composition; (3) the crystal growth rate is controllable in a relatively small range and is measurable; and (4) temperature and P CO2 pressure can be controlled. The relative errors of the partition coefficients in the present study were estimated to be about 5%. The results seem to be promising, and suggest that more precise determination of partition coefficients could be possible via more careful experimental handling and improving the apparatus.

show abstract

Calcite and aragonite precipitation from seawater solutions of various salinities: Precipitation rates and overgrowth compositions

Cited by 230 publications

References 49 publications

Effect of CaCO3 (aragonite) saturation state of seawater on calcification of Porites coral

Effect of CaCO3 (aragonite) saturation state of seawater on calcification of Porites coral

Compaction creep of wet granular calcite by pressure solution at 28°C to 150°C

A new method for the study of trace element partitioning between calcium carbonate and aqueous solution: A test case for Sr and Ba incorporation into calcite

Contact Info

Product

Resources

About