Skip to main content
Log in

Geologic controls of hydrothermal activity in the Mid-Atlantic Ridge rift valley: Tectonics and volcanics

  • Part III
  • Published:
Marine Geophysical Researches Aims and scope Submit manuscript

Abstract

The rift valley at three widely separated sites along the Mid-Atlantic Ridge is characterized using geological and geophysical data. An analysis of bottom photographs and fine-scale bathymetry indicates that each study area has a unique detailed geology and structure. Spreading rates are apparently asymmetric at each site. Relationships between tectonic and volcanic structure and hydrothermal activity show that various stages in the evolution of the rift valley are most favorable for seafloor expression of hydrothermal activity. In a stage found at 26°08′ N, site 1 (TAG), the rift valley is narrow, consisting of both a narrow volcanically active valley floor and inner walls with small overall slopes. High-temperature hydrothermal venting occurs along the faster spreading eastern inner wall of this U-shaped rift valley. Site 2 (16°46′ N) has a narrow valley floor and wide block faulted walls and is at a stage where the rift valley is characterized by a V-shape. No neovolcanic zone is observed within the marginally faulted, predominantly sedimented floor and hydrothermal activity is not observed. The rift valley at site 3 (14°54′ N), with postulated extrusive volcanic activity and a stage in valley evolution tending toward a U-shape, shows evidence of hydrothermal activity within the slightly faster spreading eastern inner wall. Evidence for tectonic activity (inward- and outward-facing faults and pervasive fissuring) exists throughout the wide inner wall. Hydrothermal activity appears to be favored within a U-shaped rift valley characterized by a narrow neovolcanic zone and secondarily faulted inner walls.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • BäckerH., LangeJ., and MarchigV., 1985, Hydrothermal Activity and Sulfide Formation in Axial Valleys of the East Pacific Rise Crest between 18 and 22° S, Earth Planet. Sci. Lett. 72, 9–22.

    Google Scholar 

  • BallardR. D. and vanAndelT. H., 1977, Morphology and Tectonics of the Inner Rift Valley at Latitude 36°50′ N on the Mid-Atlantic Ridge, Geol. Soc. Am. Bull. 88, 507–530.

    Google Scholar 

  • BerggrenW. A., KentD. V., FlynnJ. J., and vanCouveringJ. A., 1985, Cenozoic Geochronology, Geol. Soc. Am. Bull. 96, 1407–1418.

    Google Scholar 

  • ChoukrouneP., FrancheteauJ., and HekinianR., 1984, Tectonics of the East Pacific Rise near 12°50′ N: A Submersible Study, Earth Planet. Sci. Lett. 68, 115–127.

    Google Scholar 

  • ColletteB. J., SlootwegA. P., VerhoefJ., and RoestW. R., 1984, Geophysical Investigations of the Floor of the Atlantic Ocean Between 10° and 38° N (Kroonvlag-project), Geophysics, Proceedings B 87, 1–76.

    Google Scholar 

  • CraneK. and BallardR. D., 1980, The Galapagos Rift at 86° W: 4. Structure and Morphology of Hydrothermal Fields and their Relationship to the Volcanic and Tectonic Processes of the Rift Valley, J. Geophys. Res. 85, 1443–1454.

    Google Scholar 

  • CraneK. and BallardR. D., 1981, Volcanics and Structure of the FAMOUS Narrowgate Rift: Evidence for Cyclic Evolution: AMAR 1, J. Geophys. Res. 86, 5112–5124.

    Google Scholar 

  • CraneK., AikmanF., EmbleyR., HammondS., MalahoffA., and LuptonJ., 1985, The Distribution of Geothermal Fields on the Juan de Fuca Ridge, J. Geophys. Res. 90, 727–744.

    Google Scholar 

  • Detrick, R. S., Ryan, W. B. F., Mayer, L., Fox, P. J., Kong, L., Manchester, K., Kasten, K., Karson, J., and Pockalny, R., 1985, Mid-Atlantic Ridge/Kane Fracture Zone, Final Site Survey Rept., prepared for Joint Oceanographic Institutions, Inc.

  • Detrick, R. S., Fox, P. J., Schulz, N., Pockalny, R., Kong, L., Mayer, L., and Ryan, W. B. F., 1988, Geologic and Tectonic Setting of the MARK Area, in Proceedings of the Ocean Drilling Program, 106/109, Part A, 15–22.

  • FrancheteauJ. and BallardR. D., 1983, The East Pacific Rise near 21° N, 13° N and 20° S: Inferences for Along-strike Variability of Axial Processes of the Mid-Ocean Ridge, Earth Planet. Sci. Lett. 64, 93–116.

    Google Scholar 

  • HarrisonC. G. A. and StieltjesL., 1977, Faulting Within the Median Valley, Tectonophysics 38, 137–144.

    Google Scholar 

  • KappelE. S. and RyanW. B., 1986, Volcanic Episodicity and a Non-Steady State Rift Valley Along Northeast Pacific Spreading Centers: Evidence from Sea MARC I, J. Geophys. Res. 91, 13,925–13,940.

    Google Scholar 

  • KarsonJ. A., 1986, Along-Axis Variations in the MARK Area, EOS Trans. AGU 67, 659.

    Google Scholar 

  • KarsonJ. A. and DickH. J. B., 1983, Tectonics of Ridge-Transform Intersections at the Kane Fracture Zone, Mar. Geophys. Res. 6, 51–98.

    Google Scholar 

  • Karson, J. A., Thompson, G., Humphris, S. E., Edmond, J. M., Bryan, W. B., Brown, J. R., Winters, A. T., Pockalny, R. A., Casey, J. F., Campbell, A. C., Klinkhammer, G., Palmer, M. R., Kinzler, R. J., and Sulanowska, M. M., Along-axis Variations in Seafloor Spreading in the MARK Area, Nature 328, 681–685.

  • KlinkhammerG., RonaP., GreavesM., and ElderfieldH., 1985, Hydrothermal Manganese Plumes in the Mid-Atlantic Ridge Rift Valley, Nature 314, 727–731.

    Google Scholar 

  • LalouC., ThompsonG., RonaP. A., BrichetE., and JehannoC., 1986, Chronology of Selected Hydrothermal Mn Oxide Deposits from the Trans-Atlantic Geotraverse TAG Area, Mid-Atlantic Ridge 26° N, Geochim. Cosmochim. Acta 50, 1737–1743.

    Google Scholar 

  • Laughton, A. S. and Searle, R. C., 1979, Tectonic Processes on Slow Spreading Ridges, in Deep Drilling Results in the Atlantic Ocean: Ocean Crust, Maurice Ewing Series 2, 15–32.

  • Leg 106 Scientific Party: 1986, Drilling the Snake Pit Hydrothermal Sulfide Deposit on the Mid-Atlantic Ridge, Latitude 23°22′ N, Geology 14, 1004–1007.

    Google Scholar 

  • LichtmanG. S. and EissenJ-P., 1983, Time and Space Constraints on the Evolution of Medium-Rate Spreading Centers, Geology 11, 592–595.

    Google Scholar 

  • MacdonaldK. C., 1977, Near-Bottom Magnetic Anomalies, Asymmetric Spreading, Oblique Spreading, and Tectonics of the Mid-Atlantic Ridge Near Latitude 37° N, Geol. Soc. Am. Bull. 88, 541–555.

    Google Scholar 

  • MacdonaldK. C., 1982, Mid-Ocean Ridges: Fine Scale Tectonic, Volcanic and Hydrothermal Processes Within the Plate Boundary Zone, Ann. Rev. Earth Planet. Sci. 10, 155–190.

    Google Scholar 

  • MacdonaldK., LuyendykB. P., MudieJ. D., and SpiessF. N., 1975, Near-Bottom Geophysical Study of the Mid-Atlantic Ridge Median Valley Near Latitude 37° N: Preliminary Observations, Geology 3, 211–215.

    Google Scholar 

  • McConachyT. F., BallardR. D., MottlM. J. and VonHerzenR. P., 1986, Geologic Form and Setting of a Hydrothermal Vent Field at Lat 10°56′ N, East Pacific Rise: A Detailed Study using Angus and Alvin, Geology 14, 295–298.

    Google Scholar 

  • McGregorB. A. and RonaP. A., 1975, Crest of the Mid-Atlantic Ridge at 26° N, J. Geophys. Res. 80, 3307–3314.

    Google Scholar 

  • McGregorB. A., HarrisonC. G. A., LavelleJ. W., and RonaP. A., 1977, Magnetic Anomaly Patterns on Mid-Atlantic Ridge Crest at 26° N, J. Geophys. Res. 82, 231–238.

    Google Scholar 

  • NormarkW. R., MortonJ. L., KoskiR. A., ClagueD. A., and DelaneyJ. R., 1983, Active Hydrothermal Vents and Sulfide Deposits on the Southern Juan de Fuca Ridge, Geology 11, 158–163.

    Google Scholar 

  • NormarkW. R., MortonJ. L., BischoffJ. L., BrettR., HolcombR. T., KappelE. S., KoskiR. A., RossS. L., ShanksW. C., SlackJ. F., vonDammK. L., and ZierenburgR. A., 1986, Submarine Fissure Eruptions and Hydrothermal Vents on the Southern Juan de Fuca Ridge: Preliminary Observations from the Submersible Alvin, Geology 14, 823–827.

    Google Scholar 

  • Perry, R. K., Fleming, H. S., Vogt, P. R., Cherkis, N. Z., Feden, R. H., Thiede, J., and Strand, J. E., 1980, North Atlantic Ocean: Bathymetry and Plate Tectonic Evolution, Nav. Res. Lab. Acoustics Div. Map, Wash. D.C.

  • RambergI. B. and vanAndelT. H., 1977, Morphology and Tectonic Evolution of the Rift Valley at Latitude 36°30′ N, Mid-Atlantic Ridge, Geol. Soc. Am. Bull. 88, 577–586.

    Google Scholar 

  • Rona, P. A., 1980, The Central North Atlantic Ocean Basin and Continental Margins: Geology, Geophysics, Geochemistry, and Resources, Including the Trans-Atlantic Geotraverse (TAG), NOAA Atlas 3, U.S. Dept. Comm., NOAA/ERL.

  • RonaP. A., 1984, Hydrothermal Mineralization at Seafloor Spreading Centers, Earth Sci. Rev. 20, 1–104.

    Google Scholar 

  • RonaP. A. and MerrillG. F., 1978, A Benthic Invertebrate from the Mid-Atlantic Ridge, Bull. Mar. Sci. 28, 371–375.

    Google Scholar 

  • RonaP. A., HarbisonR. N., BassingerB. G., ScottR. B., and NalwalkA. J., 1976, Tectonic Fabric and Hydrothermal Activity of Mid-Atlantic Ridge Crest (Latitude 26° N), Geol. Soc. Am. Bull. 87, 661–674.

    Google Scholar 

  • RonaP. A., BoströmK., WidenfalkL., CronanD. S., and JenkinsW. J., 1984, Asymmetric Hydrothermal Activity and Tectonics of the Mid-Atlantic Ridge, 11° N to 26° N, EOS Trans. AGU 65, 974.

    Google Scholar 

  • RonaP. A., KlinkhammerG., NelsenT. A., TrefryJ. H., and ElderfieldH., 1986, Black Smokers, Massive Sulfides and Vent Biota at the Mid-Atlantic Ridge, Nature 321, 33–37.

    Google Scholar 

  • RonaP. A., WidenfalkL., and BoströmK., 1987, Serpentinized Ultramafics and Hydrothermal Activity at the Mid-Atlantic Ridge Crest Near 15° N, J. Geophys. Res. 92, 1417–1427.

    Google Scholar 

  • SaundersP. M. and FofonoffN. P., 1976, Conversion of Pressure to Depth in the Ocean, Deep-Sea Res. 23, 109–111.

    Google Scholar 

  • TempleD. G., ScottR. B., and RonaP. A., 1979, Geology of a Submarine Hydrothermal Field, Mid-Atlantic Ridge, 26° N Latitude, J. Geophys. Res. 84, 7453–7466.

    Google Scholar 

  • vanAndelT. H. and BallardR. D., 1979, The Galapagos Rift at 86° W: 2. Volcanism, Structure, and Evolution of the Rift Valley, J. Geophys. Res. 84, 5390–5406.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Eberhart, G.L., Rona, P.A. & Honnorez, J. Geologic controls of hydrothermal activity in the Mid-Atlantic Ridge rift valley: Tectonics and volcanics. Mar Geophys Res 10, 233–259 (1988). https://doi.org/10.1007/BF00310066

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00310066

Key words

Navigation