The Life Cycle of an Ocean Basin: New Insights From the Solomon Islands

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The Life Cycle of an Ocean Basin New Insights
From the Solomon Islands

• Andrew M. Goodliffe
• Geological Sciences Brown Bag
• January 26, 2005

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From http//www.galenfrysinger.com/solomon_islands
.htm
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Regional Setting
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Why did we go back?
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The Cruise
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R/V Kilo Moana
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R/V Kilo Moana
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R/V Kilo Moana
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R/V Kilo Moana
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R/V Kilo Moana
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Equipment
Courtesy Mineral Mining Agency of Japan
From E.J.W. Jones, Marine Geophysics
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EM120
Courtesy Hawaii Happing Research Group
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The Cruise
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Bathymetry
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Bathymetry
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Sidescan
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MagneticAnomaly
Robb et al, 2005
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SeafloorMagnetization
0.000-0.780 1n Brunhes/Matuyama 0.990 1.070
1r.1n Jaramillo 1.770 1.950 2n
Olduvai 2.140 2.150 2r.1n 2.581 3.040 2An.1n
Matuyama/Gauss 3.110 3.220 2An.2n 3.330 3.580
2An.3n Gauss/Gilbert 4.180 4.290 3n.1n
Cochiti 4.480 4.620 3n.2n Nunivak 4.800
4.890 3n.3n Sidufjall 4.980 5.230 3n.4n
Thvera 5.894 6.137 3An.1n 6.269 6.567 3An.2n
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Southern Rifted Margin
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Southern Rifted Margin
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Segmentation Transform Faults
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Abyssal Hills and Magma Supply
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Subduction
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Triple Junction
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Arc Volcanism
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Seamount Subduction
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Seamount Subduction
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Dominguez et al., Tectonics 19 (1), 182-196, 2000
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Seamount Subduction
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Seamount Subduction
Dominguez et al., Tectonics 19 (1), 182-196, 2000
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Ridge Subduction
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From http//www.iris.edu/about/ENO/iows/6_2004a.h
tm (Fred Taylor Kathy Ellins, UTIG)
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Key Conclusions

• The Woodlark Basin is the first marginal ocean
  basin to be fully mapped from inception to
  destruction
• The earliest stages of basin opening resulted in
  an anomalously long and deep rift basin perhaps
  a reactivation of an old sutured subduction zone
• Offsets on abyssal hills may be a function of
  magma supply
• Implications for previous propagation models
• Transforms form after the initiation of seafloor
  spreading
• Subduction of seamounts and ridges has resulted
  in a cuspate trench trace and a deformed forearc
  resulting in the uplift and subsidence of the
  overlying islands

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