Uniform pelagic sediment thicknesses reveal extents of lava flows at the Galapagos spreading centre

What is it about?

High productivity of plankton at the equator leads to high sedimentation rates of particles at the seabed. In this area of only modest current influence, the thickness of these pelagic sediments was mapped out using archived sonar data from Scripps' Deep Tow. The results revealed the pattern of lava flows about the mid-ocean ridge spreading centre near the Galapagos Islands, from areas of relatively uniform sediment thickness. Furthermore, these lava flows make the oceanic crust slightly younger than we might predict based merely on the spreading rate and distance from the ridge axis, an age anomaly that was constrained to be less than 150 ky here.

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Why is it important?

Constraining the crustal age anomaly based on radiometric data is problematic because of the difficulty of analyzing sufficient samples to reduce uncertainty ranges. The sediment mapping in contrasts has the advantage of large amounts of data, reducing nominal uncertainty ranges.