Topographic Expression of the Gulf of Aden Spreading System and its Tectonics: Hotspots-Ridge Interaction in Gulf of Aden
Abstract
Gulf of Aden is a young ocean basin formed by the rifting of Arabia away from Somalia (NE Africa). The Arabian plate moves away from Africa in a NE direction, at a rate of about 2 cm/yr. The rifting started from Early Miocene. After the, the Gulf of Aden spreding system is propagating westward into the Arabia-Africa continent (Manighetti et al., 1997). It reached the Afar hotspot area about 10 Ma (Manighetti et al., 1998). The spreading system continues to interact with the hotspot up to the present. Tamsett and Searle (1988) exposed that strike of segmentations of the spreading center in Gulf of Aden is NW-SE, although the trend of the spreading system is ENE. Their survey showed the general topographic features of the spreading system, but more detailed survey is necessary to reveal the tectonics of the Gulf of Aden, especially hotspot-ridge interaction. The bathymetric survey by the SEA BEAM 2120 multi-narrow beam echo sounders aboard the R/V Hakuho-maru was carried out along the spreading system of the Gulf of Aden between 45\deg30'E and 50° 20'E from December 2000 to January 2001. The interval of the track lines is 4-6 km. The trend of the track lines is N70\degE. Geomagnetic and gravity fields were measured during the bathymetric. The topographic expression of the spreading centers east of N46° 20'E is an axial rift valley offset by transform faults similar to that observed at slow spreading centers. The trend of the axial rift valley is N65\degW. The offset of the spreading centers increases in length to the east as Tamsett and Searle (1988) indicated. The axial rift valley west of N46° 20'E, which has an east-west direction, is not offset by any prominent transform faults. N65\deg$W trending en-echelon basins are situated in the rift valley similar to that of the western Gulf of Aden spreading system (Dauteuil, et al. 2001).
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFM.T42C0948N
- Keywords:
-
- 3000 MARINE GEOLOGY AND GEOPHYSICS;
- 3035 Midocean ridge processes;
- 3040 Plate tectonics (8150;
- 8155;
- 8157;
- 8158);
- 8121 Dynamics;
- convection currents and mantle plumes;
- 8150 Plate boundary: general (3040)