Trends and rhythms in global seafloor generation rate

被引:77
作者
Cogné, JP
Humler, E
机构
[1] Inst Phys Globe, Lab Paleomagnetisme, CNRS, UMR 7577, F-75252 Paris 05, France
[2] Univ Paris 07, F-75252 Paris, France
[3] Inst Phys Globe, Lab Geosci Marines, CNRS, UMR 7097, F-75252 Paris 05, France
来源
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS | 2006年 / 7卷
关键词
oceanic crust; production rates; spreading rates; global change : oceans; marine geology and geophysics : midocean ridge processes; oceanography : general : ocean data assimilation and reanalysis;
D O I
10.1029/2005GC001148
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
The primary purpose of this paper is to investigate the spreading and production rates of oceanic ridges for the last 180 Myr, based on the detailed analysis of eight oceanic units (North, Central, and South Atlantic basins, Southwest, Central, and Southeast Indian Ridge systems, Somalia basin, and the Pacific plate) and using the most recent timescale for oceanic isochrons. The global study of oceanic ridges presented here shows that (1) the average rate of spreading, which we computed by weighting the rates obtained at each basin by the relevant ridge lengths, is constant since similar to 125 Ma at 53.4 +/- 5.9 mm yr(-1) (full rate), (2) the average surface production rate is 2.7 +/- 0.2 km 2 yr(-1), and (3) the minimum oceanic crust production in volume, or flux, is 18.7 +/- 2.9 km(3) yr(-1). These estimations are in close agreement (within +/- 10%) with other studies. However, the new results emerging from this analysis are the following: (1) The Cretaceous flux rates (in volume) might be only 10% higher than today over a short period of time (125-100 Myr). (2) The "pulse" of ocean crustal production (120-80 Ma) in the world total is predominantly the result of contributions from mantle temperature and oceanic plateaus but is not linked to the global spreading rate of oceanic ridges, as generally accepted. (3) The rates presented here differ from previously published models for the Cenozoic and show a general increasing trend in the last 50 Myr. (4) We finally suggest a possible similar to 25 Myr pseudo-periodicity of the oceanic production rate (in surface and in volume) at least during the last 75-80 Myr. These data could have a profound impact on a vast number of models including sea-level changes and more generally on the chemical mass balance between ocean and continent, which is known to be a key parameter in the history of the Earth's climate and ocean chemistry.
引用
收藏
页数:17
相关论文
共 44 条
[1]  
ANDERSON AT, 1974, GEOL SOC AM BULL, V85, P1485, DOI 10.1130/0016-7606(1974)85<1485:CSAWIM>2.0.CO
[2]  
2
[3]   THE CARBONATE-SILICATE GEOCHEMICAL CYCLE AND ITS EFFECT ON ATMOSPHERIC CARBON-DIOXIDE OVER THE PAST 100 MILLION YEARS [J].
BERNER, RA ;
LASAGA, AC ;
GARRELS, RM .
AMERICAN JOURNAL OF SCIENCE, 1983, 283 (07) :641-683
[4]   3GEOCARB-II - A REVISED MODEL OF ATMOSPHERIC CO2 OVER PHANEROZOIC TIME [J].
BERNER, RA .
AMERICAN JOURNAL OF SCIENCE, 1994, 294 (01) :56-91
[5]   REVISED CALIBRATION OF THE GEOMAGNETIC POLARITY TIMESCALE FOR THE LATE CRETACEOUS AND CENOZOIC [J].
CANDE, SC ;
KENT, DV .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 1995, 100 (B4) :6093-6095
[6]   Temporal variation of oceanic spreading and crustal production rates during the last 180 My [J].
Cogné, JP ;
Humler, E .
EARTH AND PLANETARY SCIENCE LETTERS, 2004, 227 (3-4) :427-439
[7]   PaleoMac:: A Macintosh™ application for treating paleomagnetic data and making plate reconstructions -: art. no. 1007 [J].
Cogné, JP .
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, 2003, 4
[8]   Modeling seafloor-spreading rates through time [J].
Demicco, RV .
GEOLOGY, 2004, 32 (06) :485-488
[9]  
Engebretson D., 1985, SPEC PAP GEOL SOC AM, V206, P1
[10]  
ENGEBRETSON DC, 1992, GSA TODAY, V2, P100