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Updated: May 29, 2026
06:55
Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling
Published on: August 5, 2016
Lower-crustal intrusion on the North Atlantic continental margin
R S White1, L K Smith, A W Roberts
1Bullard Laboratories, University of Cambridge, Madingley Road, Cambridge CB3 0EZ, UK.
Nature
|March 28, 2008
Summary
Continental rifting produced large volumes of basaltic melt, with most intruded into the lower crust as sills. Increased mantle temperatures, not mantle convection, likely drove this magmatism during continental break-up.
Area of Science:
- Geophysics
- Tectonics
- Volcanology
Background:
- Continental rifting can generate significant magmatism, but melt volumes and causes remain debated.
- The role of mantle temperature versus other factors in driving magmatism during break-up is unclear.
Purpose of the Study:
- To quantify melt volumes and understand emplacement mechanisms at volcanic rifted margins.
- To investigate the primary drivers of magmatism during continental break-up.
Main Methods:
- Acquisition and analysis of deep-penetration seismic profiles (normal-incidence and wide-angle).
- Interpretation of seismic data to map melt intrusions and extrusions.
Main Results:
- Quantified basalt extrusion (360-400 km³/km) and intrusion (540-600 km³/km) volumes at the Faroe and Hatton Bank margins.
- Identified lower-crustal intrusions as focused sills, not a continuous 'underplate'.
- Extruded basalts spread over 100 km from the rift axis.
Conclusions:
- Melt production was primarily controlled by increased mantle temperatures.
- Significant active mantle convection or fertile mantle presence was not required to explain the observed magmatism.
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