Publication Date:
2021-01-27
Description:
Northern Victoria Land is located at the boundary
between an extended, presumably hot, region (West
Antarctic Rift System) and the thick, possibly cold,
East Antarctic craton. The style and timing of Tertiary
deformation along with relationships with the
magmatic activity are still unclear, and contrasting
models have been proposed. We performed structural
and morphotectonic analyses at the NE termination of
northern Victoria Land in the Admiralty Mountains
area, where the relationship between topography,
tectonics, and magmatism is expected to be well
pronounced. We found evidence of two subsequent
episodes of faulting, occurring concurrently with the
Neogene McMurdo volcanism. The first episode is
associated with dextral transtension, and it is
overprinted by extensional tectonics during the
emplacement of large shield alkaline volcanoes.
Upper mantle seismic tomography shows that the
extensional regime is limited to regions overlying a
low-velocity anomaly. We interpret this anomaly to be
of thermal origin, and have tested the role of largescale
upwelling on lithosphere deformation in the area.
The results of this integrated analysis suggest that the
morphotectonic setting of the region and the
magmatism is likely the result of upwelling flow at
the boundary between the cold cratonic and the hot
stretched province (WARS), at work until recent time
in this portion of the northern Victoria Land.
Description:
Published
Description:
TC4015
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
JCR Journal
Description:
partially_open
Keywords:
Antarctica
;
Admiralty Mountains
;
Extensional Tectonics
;
Mantle Upwelling
;
Seismic Tomography
;
04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
