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Evolution of an active sea-floor massive sulphide deposit

Abstract

Hydrothermal circulation at oceanic spreading ridges causes sea water to penetrate to depths of 2 to 3 km in the oceanic crust where it is heated to 400 °C before venting at spectacular ‘black smokers’. These hydrothermal systems exert a strong influence on ocean chemistry1, yet their structure, longevity and magnitude remain largely unresolved2. The active Transatlantic Geotraverse (TAG) deposit, at 26° N on the Mid-Atlantic Ridge, is one of the largest, oldest and most intensively studied of the massive sulphide mounds that accumulate beneath black-smoker fields. Here we report ages of sulphides and anhydrites from the recently drilled3 TAG substrate structures — determined from 234U–230Th systematics analysed by thermal ionization mass spectrometry. The new precise ages combined with existing data4,5 show that the oldest material (11,000 to 37,000 years old) forms a layer across the centre of the deposit with younger material (2,300–7,800 years old) both above and below. This stratigraphy confirms that much of the sulphide and anhydrite are precipitated within the mound by mixing of entrained sea water with hydrothermal fluid6. The age distribution is consistent with episodic activity of the hydrothermal system recurring at intervals of up to 2,000 years.

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Figure 1: Stratigraphy of the TAG mound modified after Humphris et al.3.
Figure 2: 230Th/232Th–238U/232Th isochron diagram of five pyrite samples (filled squares) and one anhydrite sample (open square) from 957G-3N-1-44-47.
Figure 3: Frequency–age diagram for TAG sulphide and anhydrite samples with 2σ errors <600 years.
Figure 4: Schematic stages in the evolution of the TAG hydrothermal mound.

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References

  1. Edmond, J. M. et al. Ridge crest hydrothermal activity and the balances of the major and minor elements in the ocean: The Galapagos data. Earth Planet. Sci. Lett. 46, 1–18 (1979).

    Article  ADS  CAS  Google Scholar 

  2. Elderfield, H. & Elderfield, H. & Schultz, A. Mid-ocean ridge hydrothermal fluxes and the chemical composition of the ocean. Annu. Rev. Earth Planet. Sci. 24, 191–224 (1996).

    Article  ADS  CAS  Google Scholar 

  3. Humphris, S. E. et al. The internal structure of an active sea-floor massive sulphide deposit. Nature 377, 713–716 (1995).

    Article  ADS  CAS  Google Scholar 

  4. Lalou, C. et al. New age data for Mid-Atlantic ridge hydrothermal sites: TAG and Snake Pit chronology revisited. J. Geophys. Res. 98, 9705–9713 (1993).

    Article  ADS  CAS  Google Scholar 

  5. Lalou, C., Reyss, J. L. & Brichet, E. Age of sub-bottom sulphide samples at the TAG active mound. Proc. ODP Sci. Res. 158, 111–118 (1998).

    CAS  Google Scholar 

  6. James, R. H. & Elderfield, H. Chemistry of ore-forming fluids and mineral formation rates in an active hydrothermal sulfide deposit on the mid-Atlantic Ridge. Geology 24, 1147–1150 (1996).

    Article  ADS  CAS  Google Scholar 

  7. Cann, J. R., Strens, M. R. & Rice, A. Asimple magma-driven thermal balance model for the formation of volcanogenic massive sulphides. Earth Planet. Sci. Lett. 76, 123–134 (1985).

    Article  ADS  CAS  Google Scholar 

  8. Wilcock, S. D. & Delany, J. R. Mid-ocean ridge sulfide deposits: evidence for heat extraction from magma chambers or cracking fronts? Earth Planet. Sci. Lett. 145, 49–64 (1996).

    Article  ADS  CAS  Google Scholar 

  9. Converse, D. R., Holland, H. D. & Edmond, J. M. Flow rates in the axial hot springs of the East Pacific Rise (21° N): implications for the heat budget and the formation of massive sulfide deposits. Earth Planet. Sci. Lett. 69, 159–175 (1984).

    Article  ADS  Google Scholar 

  10. Schultz, A., Delany, J. R. & McDuff, R. E. On the partitioning of heat flux between diffuse and point souce venting. J. Geophys. Res. 97, 12299–12314 (1992).

    Article  ADS  Google Scholar 

  11. Lister, C. R. B. Heat transfer between magmas and hydrothermal systems, or, six lemmas in search of a theorem. Geophys. J. Int. 120, 45–59 (1995).

    Google Scholar 

  12. Edwards, R. L., Chen, J. H. & Wasserburg, G. J. 238U–234U–230Th–232Th systematics and the precise measurement of time over the past 500,000 years. Earth Planet. Sci. Lett. 81, 175–192 (1986).

    Article  ADS  Google Scholar 

  13. Mills, R., Thompson, J., Elderfield, H., Hinton, R. W. & Hyslop, E. Uranium enrichment in metalliferous sediments from the Mid-Atlantic Ridge. Earth Planet. Sci. Lett. 124, 35–47 (1994).

    Article  ADS  CAS  Google Scholar 

  14. Henderson, G. M., Cohen, A. S. & O'Nions, R. K. 234U/238U ratios and 230Th ages for Hateruna Atoll corals: implications for coral diagenesis and seawater 234U/238U ratios. Earth Planet. Sci. Lett. 115, 65–73 (1993).

    Article  ADS  CAS  Google Scholar 

  15. You, C.-F., Bickle, M. J., Mills, R., Nesbitt, R. & Butler, I. Age and uranium mobility in hydrothermal sulphides. Terra Nova(Abstr. Suppl. 9) 555 (1997).

  16. Humphris, S. E. et al. Explanatory notes. Proc. ODP Init Rep. 158, 37–53 (1996).

    Google Scholar 

  17. Humphris, S. E. et al. Introduction and principal reuslts. Proc. ODP Init. Rep. 158, 5–14 (1996).

    Google Scholar 

  18. York, D. Least squares fitting of a straight line with correlated errors. Earth Planet. Sci. Lett. 5, 320–324 (1969).

    Article  ADS  CAS  Google Scholar 

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Acknowledgements

We thank ODP and the staff at the Bremen core depository for collecting and curating samples; R. Mills, R. Nesbitt and I. Butler for discussions; and C. Lalou for making available a preprint of her work. This work was funded by NERC and the Newton Trust.

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Correspondence to M. J. Bickle.

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You, CF., Bickle, M. Evolution of an active sea-floor massive sulphide deposit. Nature 394, 668–671 (1998). https://doi.org/10.1038/29279

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