Continental break-up and the onset of ultraslow seafloor spreading off Flemish Cap on the Newfoundland rifted margin
Research output: Contribution to journal › Journal article › Research › peer-review
Prestack depth-migrated seismic reflection data collected off Flemish Cap on the Newfoundland margin show a structure of abruptly thinning continental crust that leads into an oceanic accretion system. Within continental crust, there is no clear evidence for detachment surfaces analogous to the S reflection off the conjugate Galicia Bank margin, demonstrating a first-order asymmetry in final rift development. Anomalously thin (3-4 km), magmatically produced oceanic crust abuts very thin continental crust and is highly tectonized. This indicates that initial accretion of the oceanic crust was in a magma-limited setting similar to present-day ultraslow spreading environments. Seaward, oceanic crust thins to <1.3 km and exhibits an unusual, highly reflective layering. We propose that a period of magma starvation led to exhumation of mantle in an oceanic core complex that was subsequently buried by deep-marine sheet flows to form this layering. Subsequent seafloor spreading formed normal, ∼6-km-thick oceanic crust. This interpretation implies large fluctuations in the available melt supply during the early stages of seafloor spreading before a more typical slow-spreading system was established.
Original language | English |
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Journal | Geology |
Volume | 32 |
Issue number | 1 |
Pages (from-to) | 93-96 |
Number of pages | 4 |
ISSN | 0091-7613 |
DOIs | |
Publication status | Published - Jan 2004 |
- Continental breakup, Continental margin, Extension tectonics, Seafloor spreading
Research areas
ID: 355633864