Eighty Five East Ridge

[1] The northern part of the ridge is buried beneath thick sediments of the Bengal Fan and shows a negative gravity anomaly.

[1] Ridge structures in the south occasionally rise above the sea floor and are associated with a positive gravity anomaly.

[1] The magnetic signatures associated with the ridge are complex, with alternate stripes of strong positive and negative anomalies.

[1] Magnetic modelling of the ridge suggests that it was emplaced over a period of rapid geomagnetic reversals whereas the underlying oceanic crust was formed in a normal magnetic field of the Cretaceous normal superchron or "Cretaceous quiet period".

[1] The correlation of the magnetization pattern of the ridge and the geomagnetic polarity timescale suggests that the volcanism that created the ridge started ~80 Ma (magnetic chron time 33r) in the Mahanadi Basin and the process continued southwards, ending at ~55 Ma near the Afanasy Nikitin Seamount.