Eighty Five East Ridge

The Eighty Five East Ridge or 85°E Ridge is a near-linear, aseismic, age-progressive ridge in the northeastern Indian Ocean. It is named for its near-parallel strike along the 85th meridian.^[1] It is one of two major aseismic ridges in the Bay of Bengal, the other being the Ninety East Ridge.^[2] The feature extends from the Mahanadi Basin in the north, off the northeastern coast of India, shifts westwards by about 250 km around 5°N, southeast of Sri Lanka and continues south to the Afanasy Nikitin Seamount in the Central Indian Basin.^[3]

No wells have been drilled on the ridge.

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.^[1] There are several proposals to explain the origin and development of the ridge, one of which is that the volcanism was caused by a short-lived hotspot.^[1]

References

^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Michael, Laju; K. S. Krishna (May 2011). "Dating of the 85°E Ridge (northeastern Indian Ocean) using marine magnetic anomalies". Current Science. 100 (9). Indian Academy of Sciences: 1314–1322.
^ ^a ^b ^c Sar, D.; M.K. Maheshwari; S. Rangarajan; C. S. Bahuguna (July 2009). "Eighty five degrees east ridge & its hydrocarbon potential" (PDF). Geohorizons. 15. Society of Petroleum Geophysicists (SPG), India.
doi:10.1007/s12040-011-0099-9
.

Further reading

Bastia, Rabi; M. Radhakrishna; Suman Das; Anand S. Kale; Octavian Catuneanu (October 2010). "Delineation of the 85°E ridge and its structure in the Mahanadi Offshore Basin, Eastern Continental Margin of India (ECMI), from seismic reflection imaging". doi:10.1016/j.marpetgeo.2010.08.003
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Tabea Altenbernd; Wilfried Jokat; Wolfram Geissler (20 June 2020). "The bent prolongation of the 85°E Ridge south of 5°N – Fact or fiction?". doi:10.1016/j.tecto.2020.228457
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Retrieved from "https://en.wikipedia.org/w/index.php?title=Eighty_Five_East_Ridge&oldid=1031855313"

[Michael-1] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Michael, Laju; K. S. Krishna (May 2011). "Dating of the 85°E Ridge (northeastern Indian Ocean) using marine magnetic anomalies". Current Science. 100 (9). Indian Academy of Sciences: 1314–1322.

[Sar-2] Sar, D.; M.K. Maheshwari; S. Rangarajan; C. S. Bahuguna (July 2009). "Eighty five degrees east ridge & its hydrocarbon potential" (PDF). Geohorizons. 15. Society of Petroleum Geophysicists (SPG), India.

[Sreejith-3] doi:10.1007/s12040-011-0099-9
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