Crustal structure of Ascension Island from wide-angle seismic data: implications for the formation of near-ridge volcanic islands

Details Crustal structure of Ascension Island from wide-angle seismic data: implications for the formation of near-ridge volcanic islands Crustal structure of Ascension Island from wide-angle seismic data: implications for the formation of near-ridge volcanic islands

Jul 2001

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001e%26psl.190...41k&link_type=abstract

Earth and Planetary Science Letters, Volume 190, Issue 1-2, p. 41-56.

Physics

12

Scientific paper

The study of the internal structure of volcanic islands is important for understanding how such islands form and how the lithosphere deforms beneath them. Studies to date have focused on very large volcanic edifices (e.g., Hawaiian Islands, Marquesas), but less attention has been paid to smaller islands, which are more common. Ascension Island, a 4-km high volcanic edifice with a basal diameter of 60 km, is located in the equatorial Atlantic (8°S), 90 km west of the Mid-Atlantic Ridge on 7 Ma oceanic lithosphere. We present results of a wide-angle seismic profile crossing the island revealing a crustal thickness of 12-13 km, an overthickened layer 3 (7 km thick) and little evidence of lithospheric flexure. Together these results suggest Ascension Island may be older than previously assumed and may have begun forming at an on-axis position around 6-7 Ma. This hypothesis is further supported by the presence of a young 1.4-km high edifice directly adjacent to the Mid-Atlantic Ridge with a volume about 1/7 that of Ascension Island, possibly representing the earliest stages of seamount formation. Excess magmatism appears to be related to the tectonic setting at the ridge-fracture zone intersection.

Affiliated with

Also associated with

No associations

Rating

Crustal structure of Ascension Island from wide-angle seismic data: implications for the formation of near-ridge volcanic islands does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Crustal structure of Ascension Island from wide-angle seismic data: implications for the formation of near-ridge volcanic islands, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Crustal structure of Ascension Island from wide-angle seismic data: implications for the formation of near-ridge volcanic islands will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1777524