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Hotspot volcanism along a leaky fracture zone contributes the formation of the 85°E Ridge at 11°N latitude, Bay of Bengal.
- Source :
-
Tectonophysics . Aug2022, Vol. 837, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
-
Abstract
- The 85°E Ridge is a prominent linear structure in the northeastern Indian Ocean. Its nature and origin are still controversial due to the coverage of thick Bengal Fan sediments. Here we present a newly collected 400-km-long 2-D seismic reflection profile which crosses the 85°E Ridge near 11°N and shows the basement morphology and internal structures of the ridge. The ridge has a thickened crust characterized by two basement highs rising up to ~2–3 km above the surrounding oceanic crust and a Moho depression with amplitude of ~3–4 km. Typical volcanic structures formed by hotspot volcanism are identified in the ridge. Deep-rooted faults played important roles in the formation of the 85°E Ridge. They acted as the preferred conduit for the upwelling of hotspot melts, but their syn - and post-volcanic reactivations induced the collapse of volcanic sequences and the relative uplift of the East Ridge. These observations support that the 85°E Ridge near 11°N having formed by hotspot magmatism drained along a leaky fracture zone. Combined with previous results, a new single-hotspot formation model of the 85°E Ridge is proposed, in which the entire 85°E Ridge was formed by a weak and pulsating mantle plume acting on the northward drifting Indian Plate. Its along-strike variations in location, morphology, and structure in different segments are interpreted to reflect different elastic strength of the oceanic lithosphere and the existence of a pre-existing fracture zone which laterally redistributed the shallow melts. • The 85°E Ridge at 11°N is characterized by basement uplift and Moho depression. • The ridge is separated into the West and East Ridges by a deep-rooted fault. • Typical volcanic structures are identified in the ridge. • Hotspot volcanism along a leaky fracture zone contributes the formation of the ridge. • The entire 85°E Ridge was formed by a single hotspot acting on the Indian Plate. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00401951
- Volume :
- 837
- Database :
- Academic Search Index
- Journal :
- Tectonophysics
- Publication Type :
- Academic Journal
- Accession number :
- 158055645
- Full Text :
- https://doi.org/10.1016/j.tecto.2022.229453