浮游有孔虫B/Ca作为海水pH替代指标有效性的初步评估：生命效应和溶解作用

郭景腾; 李铁刚; 于心科; 熊志方; 常凤鸣

doi:10.16562/j.cnki.0256-1492.2015.06.011

浮游有孔虫B/Ca作为海水pH替代指标有效性的初步评估：生命效应和溶解作用

1. 中国科学院海洋研究所海洋地质与环境重点实验室, 青岛 266071;
2. 中国科学院大学, 北京 100049

基金项目:

中国科学院战略性先导科技专项项目(XDA10010305)

国家自然科学基金项目(41230959,41106042)

国家海洋局项目"全球变化及海气相互作用"专项(GASI-04-01-02)

详细信息

作者简介:
郭景腾(1989-),男,硕士生,主要从事古海洋与古环境研究,E-mail:Guojt625@163.com

中图分类号: P736.22
计量
- 文章访问数: 1693
- HTML全文浏览量: 237
- PDF下载量: 18
出版历程
- 收稿日期: 2015-02-09
- 修回日期: 2015-12-04

A PRELIMINARY EVALUATION ON B/CA OF PLANKTIC FORAMINIFERA AS A PROXY FOR SEAWATER PH: VITAL EFFECTS AND DISSOLUTION

1. Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071;
2. University of Chinese Academy of Sciences, Beijing 100049

摘要

摘要: 浮游有孔虫B/Ca主要受控于海水pH,可作为海水pH值的替代性指标,其在探索海洋对大气pCO₂冰期旋回贡献作用的研究中广受关注。然而,利用浮游有孔虫B/Ca重建海水pH,其结果的可靠性还受到温度、[CO₃^2-]、溶解作用、生命效应(共生光合作用、呼吸作用和钙化作用)以及属种差异的制约。为评估生命效应和溶解作用对B/Ca指标有效性的影响,测定了西太平洋暖池MD06-3052岩心特征样品的浮游有孔虫表层种Globigerinoides ruber和次表层种Neogloboquadrina dutertrei在不同壳体粒径、不同壳体厚度下的B/Ca。结果表明,除两个层位外,G.ruber的B/Ca随壳体粒径的增大,总体上呈增高趋势,主要由钙化作用速率逐渐加快所致;而两个特例层位分别表现为B/Ca随粒径变化不大和随粒径先不变后增加,这可能是由钙化作用、呼吸作用与共生光合作用对G.ruber B/Ca影响的相反效应导致的竞争关系所致。N.dutertrei的B/Ca随壳体粒径的增大,总体呈降低趋势,呼吸作用可能是导致该趋势的主要原因。另外,同一层位相同粒径G.ruber和N.dutertrei的B/Ca也明显不同。这些相同种属不同粒径之间以及相同粒径不同种属之间B/Ca的差异综合表明生命效应通过表征的具体过程对浮游有孔虫B/Ca有重要影响。然而,同一层位、相同粒径、不同厚度的G.ruber和N.dutertrei B/Ca各自相差不大,表明溶解作用对浮游有孔虫B/Ca影响甚微。总之,从生命效应和溶解作用角度看,只要挑选优势粒径浮游有孔虫,将生命效应对其B/Ca的影响降到最低,浮游有孔虫B/Ca是有效的海水pH的替代性指标。
- 浮游有孔虫 /
- B/Ca /
- 生命效应 /
- 溶解作用
Abstract: B/Ca in the planktic foraminifera is mainly controlled by seawater pH,and thus could be used as ageochemical proxy for seawater pH.In order to explore the significance of ocean on the pCO₂ in the atmosphere in glacial cycles,the proxy has received wide concerns among researchers.However,its reliability may be influenced by various factors,such as temperature,[CO₃^2-],dissolution,vital effects(such as symbiont photosynthesis,respiration and calcification)as well as interspecies effects.To evaluate the influence of vital effects and dissolution on B/Ca of planktic foraminifera,we measured the B/Ca for Globigerinoides ruber and Neogloboquadrina dutertrei with different size and shell thickness from the core MD06-3052 in the western Pacific Warm Pool.Except for two cases,the B/Ca of G.ruber generally increases with increasing shell size,which is supposed to be controlled by increasing calcification rate.For the two special kinds of cases,the B/Ca of G.ruberfrom one sampling layer shows little change with the increase inshell size,and the figure from the other layer does not vary in the beginning and then increases with shell size.It is believed that these characteristics are caused by the opposite effect of calcification,respiration and symbiosis photosynthesis on the B/Ca of G.ruber.The B/Ca of N.dutertrei,however,generally decreases with increasing shell size which is probably controlled by respiration.In addition,the B/Ca of G.ruber and N.dutertrei are also different for same size shells in same sample layer.The differences in B/Ca insame species with different shell size and in different species with same shell size suggest that vital effects have important influence on foraminifera B/Ca through specific processes.However,that the B/Ca of G.ruber and N.dutertrei in the same sample layer do not show obvious discrepancy between the species with different shell thickness and same shell size suggests that dissolution has little effect on B/Ca.In summary,from the perspective of vital effects and dissolution,the B/Ca of planktic foraminifera is a valid proxy for seawater pH,as long as the dominant shell size is chosen to reduce the influence of vital effects on its B/Ca.
- planktic foraminifera /
- B/Ca /
- vital effects /
- dissolution

HTML全文

参考文献(38)

[1]	Barker S,Elderfield H.Foraminiferal calcification response to glacial-interglacial changes in atmospheric CO₂[J].Science, 2002,297(5582):833-836.
[2]	Palmer M R,Pearson P N.A 23,000-year record of surface water pH and pCO₂ in the Western Equatorial Pacific Ocean[J].Science,2003,300(5618):480-482.
[3]	Hönisch B,Hemming N G.Surface ocean pH response to variations in pCO₂ through two full glacial cycles[J].Earth and Planetary Science Letters,2005,236(1):305-314.
[4]	Yu J,Elderfield H,Hönisch B.B/Ca in planktonic foraminifera as a proxy for surface seawater pH[J].Paleoceanography, 2007,22(2),PA2202,doi: 10.1029/2006PA001347.
[5]	Dickson A G.Thermodynamics of the dissociation of boric acid in synthetic seawater from 273.15 to 318.15 K[J].Deep Sea Research Part A.Oceanographic Research Papers,1990,37(5):755-766.
[6]	Hemming N G.Hanson G N.Boron isotopic composition and concentration in modern marine carbonates[J].Geochim.Cosmochim. Acta,1992,56:537-543.
[7]	Foster G L.Seawater pH,pCO₂ and[CO₃^2-]variations in the Caribbean Sea over the last 130 kyr:A boron isotope and B/Ca study of planktic foraminiferal[J].Earth and Planetary Science Letters,2008,271:254-266.
[8]	Sanyal A,Hemming N G,and Broecker W S,Changes in pH in the eastern equatorial Pacific across stage 5-6 boundary based on boron isotopes in foraminifera[J].Global Biogeochemical Cycles,1997,11(1):125-133.
[9]	Yu J,Thornalley D J R,Rae J W B,et al.Calibration and application of B/Ca,Cd/Ca,and δ¹¹ B in Neogloboquadrinapachyderma (sinistral)to constrain CO₂ uptake in the subpolar North Atlantic during the last deglaciation[J].Paleoceanography, 2013,28(2):237-252.
[10]	Wara M W,Delaney M L,Bullen T D,et al.Possible roles of pH,temperature,and partial dissolution in determining boron concentration and isotopic composition in planktonic foraminifera[J].Paleoceanography,2003,18(4),1100,doi: 10.1029/2002PA000797.
[11]	Allen K A,Hönisch B,Eggins S M et al.Controls on boron incorporation in cultured tests of the planktic foraminifer Orbulinauniversa[J].Earth and Planetarny Science Letters, 2011,309:291-301.
[12]	Sanyal A,Hemming N G,Broecker W S,et al.Oceanic pH control on the boron isotopic composition of foraminifera:Evidence from culture experiments[J].Paleoceanography, 1996,11(5):513-517.
[13]	Ni Y,Foster G L,Bailey T,et al.A core top assessment of proxies for the ocean carbonate system in surface-dwelling foraminifers[J].Paleoceanography,2007,22(3),PA3212, doi: 10.1029/2006PA001337.
[14]	Hendry K R,Rickaby R E M,Meredith M P,et al.Controls on stable isotope and trace metal uptake in Neogloboquadrina pachyderma (sinistral)from an Antarctic sea-ice environment[J].Earth and Planetary Science Letters,2009,278:67-77.
[15]	Seki O,Foster G L,Schmidt D N et al.Alkenone and boronbased Pliocene pCO₂ records[J].Earth and Planetary Science Letters,2010,292:201-211.
[16]	Traipati A K,Roberts C D,Eagle R A.Coupling of CO₂ and Ice Sheet stability over major climate transitionsof the last 20 Million years[J].Science,2009,326:1394-1397.
[17]	Allen K A,Honisch B.The planktic foraminiferal B/Ca proxy for seawater carbonate chemistry:A critical evaluation[J].Earth and Planetary Science Letters,2012,345:203-211.
[18]	Klochko K,Cody G D,Tossell J A,et al.Re-evaluating boron speciation in biogenic calcite and aragonite using ¹¹B MAS NMR[J].Geochimicaet Cosmochimica Acta,2009,73:1890-1900.
[19]	Hönisch B,Bijma J,Russell A D,et al.The influence of symbiont photosynthesis on the boron isotopic composition of foraminifera shells[J].Marine Micropaleontology,2003,49(1):87-96.
[20]	Elderfield H,Vautravers M,Cooper M.The relationship between shell size and Mg/Ca,Sr/Ca,δ¹⁸O,andδ¹³C of species of planktonic foraminifera[J].Geochemistry,Geophysics, Geosystems,2002,3(8):1-13.
[21]	Hönisch B,Hemming N G.Ground-truthing the boron isotope-paleo-pH proxy in planktonic foraminifera shells:Partial dissolution and shell size effects[J].Paleoceanography, 2004,19(4),PA4010,doi: 10.1029/2004PA001026.
[22]	仇晓华,李铁刚,常凤鸣,等.西菲律宾海15万年以来的浊流沉积及其成因[J].海洋地质与第四纪地质,2012,32(4):157-163. [QIU Xiaohua,LI Tiegang,CHANG Fengming,et al.Turbidite deposition record and its mechanism since 150 kaBP in western Philippine sea[J].Marine Geology and Quaternary Geology,2012,32(4):157-163.]
[23]	Lea D W,Pak D K,Spero H J.Climate impact of late Quaternary equatorial Pacific sea surface temperature variations[J].Science,2000,289(5485):1719-1724.
[24]	Erez J.The source of ions for biomineralization in foraminifera and their implications for paleoceanographicproxies[J]. Reviews in Mineralogy and Geochemistry,2003,54(1):115-149.
[25]	Schmidt D N,Renaud S,Bollmann J,et al.Size distribution of Holocene planktic foraminifer assemblages:biogeography, ecology and adaptation[J].Marine Micropaleontology,2004, 50(3):319-338.
[26]	Anderson O R,Faber W W.An estimation of calcium carbonate deposition rate in a planktonic foraminifer Globigerinoides sacculifer using ⁴⁵Ca as a tracer:a recommended procedure for improved accuracy[J].The Journal of Foraminiferal Research,1984,14(4):303-308.
[27]	Tripati A K,Roberts C D,Eagle R A,et al.A 20 million year record of plankticforaminiferal B/Ca ratios:Systematics and uncertainties in pCO₂ reconstructions[J].Geochimica et Cosmochimica Acta,2011,75(10):2582-2610.
[28]	Zeebe R E,Bijma J,Wolf-Gladrow D A.A diffusion-reaction model of carbon isotope fractionation in foraminifera[J].Marine Chemistry,1999,64(3):199-227.
[29]	Zeebe R E,Wolf-Gladrow D A,Bijma J,et al.Vital effects in foraminifera do not compromise the use of δ¹¹B as a paleopH indicator:Evidence from modeling[J].Paleoceanography, 2003,18(2),1043,doi: 10.1029/2003PA000881.
[30]	Gastrich M D.Ultrastructure of a new intracellular symbiotic alga found within planktonic foraminifera[J].Journal of Phycology, 1987,23(4):623-632.
[31]	Spero H J,Parker S L.Photosynthesis in the symbiotic planktonic foraminifer Orbulina universa,and its potential contribution to oceanic primary productivity[J].The Journal of Foraminiferal Research,1985,15(4):273-281.
[32]	Spero H J,Lerche I,Williams D F.Opening the carbon isotope "vital effect" black box,2,Quantitative model for interpreting foraminiferal carbon isotope data[J].Paleoceanography, 1991,6(6):639-655.
[33]	Rosenthal Y,Boyle E A.Factors controlling the fluoride content of planktonic foraminifera:An evaluation of its paleoceanographic applicability[J].Geochimica et Cosmochimica Acta,1993,57(2):335-346.
[34]	BrownS J,Elderfield H.Variations in Mg/Ca and Sr/Ca ratios of planktonic foraminifera caused by postdepositional dissolution:Evidence of shallow Mg-dependent dissolution[J]. Paleoceanography,1996,11(5):543-551.
[35]	Dekens P S,Lea D W,Pak D K,et al.Core top calibration of Mg/Ca in tropical foraminifera:Refining paleotemperature estimation[J].Geochemistry,Geophysics,Geosystems, 2002,3(4):1-29.
[36]	De Villiers S.Foraminiferal shell-weight evidence for sedimentary calcite dissolution above the lysocline[J].Deep Sea Research Part I:Oceanographic Research Papers,2005,52(5):671-680.
[37]	Archer D,Emerson S,Reimers C.Dissolution of calcite in deep-sea sediments:pH and O₂ microelectrode results[J]. Geochimica et Cosmochimica Acta,1989,53(11):2831-2845.
[38]	Emerson S,Bender M.Carbon fluxes at the sediment-water interface of the deep-sea:calcium carbonate preservation[J]. Journal of Marine Research,1981,39:139-162.