Pulleniatina obliquiloculata shells from 16 core-top samples from the tropical Indo-Pacific Oceans are analyzed for the ratios of boron and cadmium to calcium(B/Ca and Cd/Ca). The B/Ca ratios show a very weak positive...Pulleniatina obliquiloculata shells from 16 core-top samples from the tropical Indo-Pacific Oceans are analyzed for the ratios of boron and cadmium to calcium(B/Ca and Cd/Ca). The B/Ca ratios show a very weak positive relationship with [B(OH)_4^-] and the dissolved carbonate species at the apparent calcification depth of P.obliquiloculata. The boron partition coefficients(K_D) between P. obliquiloculata B/Ca and seawater[B(OH)_4^-]/[HCO_3^-] distribute around 1.1×10^(-3)-1.3×10^(-3) with a mean value of(1.19±0.12)×10^(-3),and are significantly related to the nutrient concentration, especially phosphate. The lack of any clear correlation between the P. obliquiloculata B/Ca and seawater carbonate chemical parameters suggests that the physiochemical controls on boron incorporation are masked by the complexity of natural seawater condition. But the significant dependence of Ku on nutrient may likely be explained by a nutrient related growth-rate effect. Cd/Ca of P.obliquiloculata shows significant correlation with seawater phosphate concentration, and its partition coefficients(D_(cd)) are significantly related to temperature. A first-principle methodology of P. obliquiloculata B/Ca is applied;with the aid of Cd/Ca as a phosphate proxy and a constraint on K_D, to estimating sea water carbonate chemistry(e.g., pH). The results are fairly promising and allow us to propose the possibility to apply the combination of B/Ca and Cd/Ca proxies(and also Mg/Ca and δ^(18)O for estimating temperature and salinity) for the paleoreconstruction of seawater carbonate chemistry.展开更多
Recent deep-diving expeditions in the South China Sea(SCS)discovered abundant indigenous cold-water corals[1].Cold-water corals,preferentially inhabiting the low-latitude intermediate and deep waters with hard substra...Recent deep-diving expeditions in the South China Sea(SCS)discovered abundant indigenous cold-water corals[1].Cold-water corals,preferentially inhabiting the low-latitude intermediate and deep waters with hard substrates and a cool water temperature,have great potential to be applied in researches of the ocean interior by providing high-resolution records[2,3].展开更多
基金The National Natural Science Foundation of China(NSFC)and NSFC-Shandong Joint Fund for Marine Science Research Centers under contract Nos 41606049,U1606401 and 41376054the China Postdoctoral Science Foundation under contract No.2015M581658
文摘Pulleniatina obliquiloculata shells from 16 core-top samples from the tropical Indo-Pacific Oceans are analyzed for the ratios of boron and cadmium to calcium(B/Ca and Cd/Ca). The B/Ca ratios show a very weak positive relationship with [B(OH)_4^-] and the dissolved carbonate species at the apparent calcification depth of P.obliquiloculata. The boron partition coefficients(K_D) between P. obliquiloculata B/Ca and seawater[B(OH)_4^-]/[HCO_3^-] distribute around 1.1×10^(-3)-1.3×10^(-3) with a mean value of(1.19±0.12)×10^(-3),and are significantly related to the nutrient concentration, especially phosphate. The lack of any clear correlation between the P. obliquiloculata B/Ca and seawater carbonate chemical parameters suggests that the physiochemical controls on boron incorporation are masked by the complexity of natural seawater condition. But the significant dependence of Ku on nutrient may likely be explained by a nutrient related growth-rate effect. Cd/Ca of P.obliquiloculata shows significant correlation with seawater phosphate concentration, and its partition coefficients(D_(cd)) are significantly related to temperature. A first-principle methodology of P. obliquiloculata B/Ca is applied;with the aid of Cd/Ca as a phosphate proxy and a constraint on K_D, to estimating sea water carbonate chemistry(e.g., pH). The results are fairly promising and allow us to propose the possibility to apply the combination of B/Ca and Cd/Ca proxies(and also Mg/Ca and δ^(18)O for estimating temperature and salinity) for the paleoreconstruction of seawater carbonate chemistry.
基金supported financially by the National Key Research&Development Program of China(2018YFE0202401)the Science and Technology Commission of Shanghai Municipalitythe National Natural Science Foundation of China(91958208 and 42076061)。
文摘Recent deep-diving expeditions in the South China Sea(SCS)discovered abundant indigenous cold-water corals[1].Cold-water corals,preferentially inhabiting the low-latitude intermediate and deep waters with hard substrates and a cool water temperature,have great potential to be applied in researches of the ocean interior by providing high-resolution records[2,3].
