Aleutian basin oceanic crust

Earth and Planetary Science Letters
By:  and 

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Abstract

We present two-dimensional P-wave velocity structure along two wide-angle ocean bottom seismometer profiles from the Aleutian basin in the Bering Sea. The basement here is commonly considered to be trapped oceanic crust, yet there is a change in orientation of magnetic lineations and gravity features within the basin that might reflect later processes. Line 1 extends ∼225 km from southwest to northeast, while Line 2 extends ∼225 km from northwest to southeast and crosses the observed change in magnetic lineation orientation. Velocities of the sediment layer increase from 2.0 km/s at the seafloor to 3.0–3.4 km/s just above basement, crustal velocities increase from 5.1–5.6 km/s at the top of basement to 7.0–7.1 km/s at the base of the crust, and upper mantle velocities are 8.1–8.2 km/s. Average sediment thickness is 3.8–3.9 km for both profiles. Crustal thickness varies from 6.2 to 9.6 km, with average thickness of 7.2 km on Line 1 and 8.8 km on Line 2. There is no clear change in crustal structure associated with a change in orientation of magnetic lineations and gravity features. The velocity structure is consistent with that of normal or thickened oceanic crust. The observed increase in crustal thickness from west to east is interpreted as reflecting an increase in melt supply during crustal formation.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Aleutian basin oceanic crust
Series title Earth and Planetary Science Letters
DOI 10.1016/j.epsl.2015.06.040
Volume 426
Year Published 2015
Language English
Publisher Elsevier
Contributing office(s) Pacific Coastal and Marine Science Center
Description 9 p.
First page 167
Last page 175
Country Russia, United States
Other Geospatial Aleutian basin, Bering Sea
Online Only (Y/N) N
Additional Online Files (Y/N) N