Possible extinct ridge between the Conrad Rise and the Del Cano Rise in the Southern Indian Ocean
Abstract
Seafloor spreading history in the Southern Indian Ocean, are vital to understanding the breakup process of Gondwana. Seafloor spreading history is estimated mainly by using the identification of magnetic anomaly lineations and fracture zone trends. Satellite gravity anomalies revealed seafloor structures such as mid-ocean ridges and fracture zones, and help to understand seafloor spreading history. On the other hand, seafloor structural lineaments, whose origin is the unknown origin, have also detected from satellite gravities. There is one of the unknown WNW-ESE trending seafloor lineament considered to be an extinct ridge between the Conrad Rise and the Del Cano Rise in the Southern Indian Ocean.
Vector magnetic anomaly measurement have been conducted onboard R/V Hakuho-maru across the unknown WNW-ESE trending seafloor lineament considered to be an extinct ridge between the Conrad Rise and Del Cano Rise. Magnetic boundary strikes are derived from vector magnetic anomalies. Obtained magnetic anomaly profiles are almost symmetric with the unknown seafloor lineament, and WNW-ESE trending magnetic anomaly lineations are inferred from strikes of magnetic boundaries between the Conrad Rise and the Del Cano Rise that are parallel to unknown seafloor lineament trend. These show that the unknown WNW-ESE trending seafloor lineament is most likely an extinct spreading center. Magnetic anomaly C24 are identified just in the north of the Del Cano Rise. Consequently, the oceanic floor between the Conrad Rise and the Del Cano Rise have been formed and seafloor spreading terminated before the magnetic anomaly C24. Obtained magnetic anomaly profiles imply the seafloor spreading ceased around the magnetic anomaly C33. We will discuss the possible extinct ridge and age of the termination of seafloor spreading between the Conrad Rise and the Del Cano Rise.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMGP31B0715N
- Keywords:
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- 1517 Magnetic anomalies: modeling and interpretation;
- GEOMAGNETISM AND PALEOMAGNETISMDE: 1519 Magnetic mineralogy and petrology;
- GEOMAGNETISM AND PALEOMAGNETISMDE: 1525 Paleomagnetism applied to tectonics: regional;
- global;
- GEOMAGNETISM AND PALEOMAGNETISMDE: 1541 Satellite magnetics: main field;
- crustal field;
- external field;
- GEOMAGNETISM AND PALEOMAGNETISM