Greenland Fracture Zone-East Greenland Ridge(s) revisited: Indications of a C22-change in plate motion?

Arne Døssing, Thomas Funck

Publikation: Bidrag til tidsskriftArtikelForskningpeer review

11 Citationer (Scopus)

Abstrakt

Changes in the lithospheric stress field, causing axial rift migration and reorientation of the transform, are generally proposed as an explanation for anomalously old crust and/or major aseismic valleys in oceanic ridge-transform-ridge settings. Similarly, transform migration of the Greenland Fracture Zone and separation of the 200-km-long, fracture-zone-parallel continental East Greenland Ridge from the Eurasia plate is thought to be related to a major change in relative plate motions between Greenland and Eurasia during the earliest Oligocene (Chron 13 time). This study presents a reinterpretation of the Greenland Fracture Zone - East Greenland Ridge based on new and existing geophysical data. Evidence is shown for two overstepping ridge segments (Segments A and B) of which Segment A corresponds to the already known East Greenland Ridge while Segment B was not detected previously. Interpretation of sonobuoy data and revised modeling of existing OBS data across Segment B indicate a continental composition of the segment. This interpretation is supported by magnetic anomaly data. The Segments A and B are bounded by portions of the Greenland Fracture Zone with a distinct ∼10° difference in strike. This is suggested to relate to an early episode of transform migration and reorientation of the lithospheric stress field around Chron 22 time, i.e., shortly after the Eocene breakup in the northern NE Atlantic. These findings contradict with previous interpretations of the fracture zone, which infer simple pre-C13 strike-slip kinematics.

OriginalsprogEngelsk
ArtikelnummerB01103
Antal sider22
TidsskriftJournal of Geophysical Research: Solid Earth
Vol/bind117
Udgave nummerB1
DOI
StatusUdgivet - 1 jan. 2012

Programområde

  • Programområde 3: Energiressourcer

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