Abstract
Detailed airborne and shipboard magnetic studies conducted over the eastern marginal basins of the southwest Pacific between New Zealand and the Solomon Islands suggest that seafloor spreading in the North Fiji Basin, which began in the latest Miocene, continues today. The North Fiji Basin is marked by at least two triple junctions, located in the central (16°50’S, 173°45’E) and northeastern (14°S, 179°30’E) parts of the basin. Both were apparently formed during the past five million years in response to continuing adjustments in the strike of the active spreading centers in the North Fiji Basin. Two additional contemporary spreading centers appear to have formed within the last one million years to the north and immediately to the west of Viti Levu. Although magnetic anomalies from 1 to 3 (0–5 Ma) are seen to form a clearly defined lineation pattern over the North Fiji Basin, earthquake foci suggest that only portions of the present North Fiji/Lau Basin spreading center system are currently active.
Analysis of the magnetic anomalies suggests that spreading began in the North Fiji Basin about 8 Ma (shortly before anomaly 4). At about 6 Ma (shortly before anomaly 3), the New Hebrides/Fiji island arc began to fragment through the development of an active spreading center (calculated half-spreading rate of 3.5 cm/yr) located between the New Hebrides and Fiji portions of the island arc. Subsequently, portions of the northeastern sector of the South Fiji Basin Plain were subducted beneath the North Fiji Basin. Between 4.5 Ma and 3.5 Ma (anomalies 3 and 2’), spreading in the North Fiji Basin extended into the Lau Basin and Havre Trough, thus separating the Tonga and Lau ridges. As a result, a distinct series of active spreading centers developed southward along the axis of the Havre Trough/Lau Basin.
The continuum of spreading centers from the North Fiji Basin into the Lau Basin and Havre Trough has been accomplished through the formation of triple junctions located in the North Fiji and northern Lau basins and propagating southward rifts in the southern Lau Basin.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Auzende, J.-M., Y. Lafoy, and B. Marsset, 1988, Recent geodynamic evolution of the north Fiji basin, Geology, v. 16, p. 925–929.
Chase, C.G., 1971, Tectonic history of the Fiji Plateau: Geological Society of America Bulletin, v. 82, p. 2087–2110.
Cherkis, N.Z., 1980, Aeromagnetic investigations and seafloor spreading history in the Lau Basin and Northern Fiji Plateau, in Proceedings, Petroleum Potential in Island Arcs, Small Ocean Basins, Submerged Margins and Related Areas Symposium, UN ESCAP, CCOP/SOPAC Technical Bulletin 3, p. 37.
Cherkis, N.Z., A. Malahoff, and J.M. Brozena, 1978, Magnetic lineations over the Fiji Plateau, EOS, Transactions, American Geophysical Union, 59, p. 266 (abstract).
Cherkis, N.Z., Malahoff, A., and Brozena, J.M., 1980, An aeromagnetic investigation of the Lau Basin and the North Fiji Plateau, Abstracts w/ Program 12, Geological Society America, Northeastearn section, 15th Annual Meeting (abstract).
Falvey, D., 1975, Arc reversals and a tectonic model for the North Fiji Basin, Australian Society for Exploration Geophysicists Bulletin, v. 6, p. 47–49.
Hamburger, M.W., and B.L. Isacks, Shallow seismicity in the North Fiji Basin: this volume.
Jurdy, D.M., 1979, Relative Plate Motions and the formation of marginal basins, Journal of Geophysical Research, v. 84, p. 6796–6802.
Karig, D.E., 1970, Ridges and basins of the Tonga-Kermadec island arc systems, Journal of Geophysical Research, v. 75, p. 239–254.
Karig, D.E., 1971, Origin and development of marginal basins in the Western Pacific, Journal of Geophysical Research, v. 76, p. 2542–2562.
Kroenke, L.W., J.V. Eade, C.Y. Yan, and R. Smith, Sediment dis- tribution in the north central North Fiji Basin: this volume.
Lawyer, L.A., J.W. Hawkins, and J.G. Sclater, 1976, Magnetic anomalies and crustal dilation in the Lau Basin, Earth and Planetary Science Letters, v. 33, p. 27–35.
LeBrecque, J.L., D.V. Kent, and S.C. Cande, 1977, Revised magnetic polarity time scale for the Late Cretaceous and Cenozoic time, Geology, v. 5, p. 330–335.
Malahoff, A., R.H. Feden, and H.S. Fleming, 1982, Magnetic anomalies and tectonic fabric of marginal basins north of New Zealand, Journal of Geophysical Research, v. 87, p. 4109–4125.
Nagumo, S., J. Kasahara, and T. Ouchi, 1975, Active seismicity in the Fiji Plateau observed by ocean-bottom seismograph, Journal of Physics of the Earth, v. 23, p. 279–287.
Nagumo, S., J. Kasahara, and T. Ouchi, 1975, Active seismicity in the Fiji Plateau observed by ocean-bottom seismograph, Journal of Physics of the Earth, v. 23, p. 279–287.
Sclater, J.F., J.M. Hawkins, J. Mammerickx, and C.G. Chase, 1972, Crustal extension between the Tonga and Lau Ridges: Petrological and geophysical evidence, Geological Society of America Bulletin, v. 83, p. 505–518.
Sinton, J.M., R.C. Price, K.M. Johnson, H. Staudigel, and A. Zindler, Petrology and geochemistry of submarine lavas from the Lau and North Fiji back-arc basins: this volume.
Watanabe, T., M.G. Langseth, and R.N. Anderson, 1977, Heat flow in back-arc basins of the western Pacific, in M. Talwani, and W.C. Pitman (eds.), Island Arcs, Deep Sea Trenches, and Back-arc Basins; Maurice Ewing Series, v. 1, p. 137–161, American Geophysical Union.
Watts, A.B., J.K. Weissel, and F.J. Davey, 1977a, Tectonic evolution of the south Fiji marginal basin, in M. Talwani, and W.C. Pitman (eds.), Island Arcs, Deep Sea Trenches, and Back-arc Basins; Maurice Ewing Series, v. 1, p. 419–427, American Geophysical Union.
Watts, A.B., J.K. Weissel, and R.L. Larson, 1977b, Sea-floor spreading in marginal basins of the Western Pacific, Tectonophysics, v. 37, p. 167–181.
Weissel, J.K., 1977, Evolution of the Lau Basin by the growth of small plates, in M. Talwani, and W.C. Pitman (eds.), Island Arcs, Deep Sea Trenches, and Back-arc Basins; Maurice Ewing Series, v. 1, p. 429–436, American Geophysical Union.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1994 Circum-Pacific Council for Energy and Mineral Resources
About this chapter
Cite this chapter
Malahoff, A., Kroenke, L.W., Cherkis, N., Brozena, J. (1994). Magnetic and Tectonic Fabric of the North Fiji Basin and Lau Basin. In: Kroenke, L.W., Eade, J.V. (eds) Basin Formation, Ridge Crest Processes, and Metallogenesis in the North Fiji Basin. Circum-Pacific Council for Energy and Mineral Resources Earth Science Series, vol 15. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-85043-1_6
Download citation
DOI: https://doi.org/10.1007/978-3-642-85043-1_6
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-57372-2
Online ISBN: 978-3-642-85043-1
eBook Packages: Springer Book Archive