CaCO3 dissolution in California continental margin sediments: The influence of organic matter remineralization

被引:82
作者
Jahnke, RA
Craven, DB
McCorkle, DC
Reimers, CE
机构
[1] WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543
[2] RUTGERS STATE UNIV,INST MARINE & COASTAL SCI,NEW BRUNSWICK,NJ 08903
关键词
DEEP-SEA SEDIMENTS; CALCIUM-CARBONATE PRESERVATION; MARINE PORE WATERS; DIFFUSIVE SUBLAYER; EARLY DIAGENESIS; BENTHIC CHAMBER; NORTH-ATLANTIC; PACIFIC-OCEAN; FLOOR; OXYGEN;
D O I
10.1016/S0016-7037(97)00184-1
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
In situ benthic flux chamber and oxygen microelectrode and shipboard porewater results have been used to quantify sea floor dissolution of CaCO3 on the continental rise adjacent to central California, USA. The porewater distributions and benthic fluxes of O-2, NO3-, TA, Ca2+, delta(13)C, and TIC are interpreted using a numerical simulation of organic matter remineralization and CaCO3 dissolution in marine sediments. The processes considered in the simulation include: organic matter oxidation by mixing and sediment accumulation. Calculated benthic fluxes of O-2, NO3-, TA, TIC, delta(13)C, and Ca2+; porewater concentrations of O-2, NO3-, and NH4+; and sediment distributions of organic carbon, CaCO3, excess Pb-210, and C-14 agree well with the measurements. Benthic fluxes of alkalinity and inferred CaCO3 dissolution rates cannot be explained on the basis of dissolution driven solely by bottom water undersaturation. If the influence of metabolically-produced CO2 is included, benthic fluxes are fully reconciled, however. This is in agreement with benthic chamber Ca2+ and delta(13)C results that independently imply substantial CaCO3 dissolution in these sediments. The above observations are in contrast to those reported by Jahnke et al. (1994) for the west African continental rise and the western equatorial Pacific where l-G diagenetic models predict dissolution fluxes larger than observed with benthic flux chambers. We conclude that the extent of metabolic CaCO3 dissolution may vary regionally. Numerous factors, such as the depth of metabolic CO2 production and CaCO3 dissolution kinetics, are known or predicted to influence metabolic dissolution, Among the factors that should be considered in reconciling these observations are: (1) the extent to which sulfate reduction and reoxidation reactions may influence acid-base properties in surface sediments and (2) the total sedimentary CaCO3 content of the sites that may influence porewater acidity through surface exchange reactions at the mineral surface. Copyright (C) 1997 Elsevier Science Ltd.
引用
收藏
页码:3587 / 3604
页数:18
相关论文
共 61 条
[1]   MODELING THE CALCITE LYSOCLINE [J].
ARCHER, D .
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 1991, 96 (C9) :17037-17050
[2]   EFFECT OF DEEP-SEA SEDIMENTARY CALCITE PRESERVATION ON ATMOSPHERIC CO2 CONCENTRATION [J].
ARCHER, D ;
MAIERREIMER, E .
NATURE, 1994, 367 (6460) :260-263
[3]   DIRECT MEASUREMENT OF THE DIFFUSIVE SUBLAYER AT THE DEEP-SEA FLOOR USING OXYGEN MICROELECTRODES [J].
ARCHER, D ;
EMERSON, S ;
SMITH, CR .
NATURE, 1989, 340 (6235) :623-626
[4]  
ARCHER DS, 1990, THESIS U WASHINGTON
[5]   ORGANIC-CARBON OXIDATION AND BENTHIC NITROGEN AND SILICA DYNAMICS IN SAN-CLEMENTE BASIN, A CONTINENTAL BORDERLAND SITE [J].
BENDER, M ;
JAHNKE, R ;
WEISS, R ;
MARTIN, W ;
HEGGIE, DT ;
ORCHARDO, J ;
SOWERS, T .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1989, 53 (03) :685-697
[6]   DISSOLUTION KINETICS OF CALCIUM-CARBONATE IN EQUATORIAL PACIFIC SEDIMENTS [J].
BERELSON, WM ;
HAMMOND, DE ;
MCMANUS, J ;
KILGORE, TE .
GLOBAL BIOGEOCHEMICAL CYCLES, 1994, 8 (02) :219-235
[7]   INSITU MEASUREMENTS OF CALCIUM-CARBONATE DISSOLUTION RATES IN DEEP-SEA SEDIMENTS [J].
BERELSON, WM ;
HAMMOND, DE ;
CUTTER, GA .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1990, 54 (11) :3013-3020
[8]  
BERGER WH, 1982, OCEANOL ACTA, V5, P249
[9]  
BERNER RA, 1980, EARLY DIAGENESIS
[10]   BENTHIC FORAMINIFERAL DISTRIBUTION AND BIOMASS RELATED TO PORE-WATER OXYGEN-CONTENT - CENTRAL CALIFORNIA CONTINENTAL-SLOPE AND RISE [J].
BERNHARD, JM .
DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS, 1992, 39 (3-4A) :585-605