Presentation Title

Geologic history of a metamorphic core complex in NW Spitsbergen

Presenter Information

Sara ParcherFollow

Advisor Information

Harmon Maher

Location

Criss Library

Presentation Type

Poster

Start Date

1-3-2019 9:00 AM

End Date

1-3-2019 10:15 AM

Abstract

A Silurian-Devonian aged metamorphic core complex has recently been recognized in northwest Spitsbergen, on the northwest corner of the Barents Shelf. A major tectonic feature of interest is the associated Keisarhjelmen mylonitic detachment zone that is 200 - 500 meters thick. Field work in 2018, 2011 and 2009, revealed a significant northward continuation of the detachment along the west side of Raudfjorden, and is well exposed along the eastern base of Marstranderfjellet. This detachment zone of the core complex separates overlying faulted Silurian - Devonian aged cover rocks from underlying deeper crustal rocks. Within the detachment, strong retrogression is more apparent as one moves from coarsest grained rocks near the bottom to finest near the top of the sequence. This retrogression history is associated with crustal thinning. Various zoning and marginal textures, as well as metamorphic index minerals, were observed in thin section, suggesting a strong metamorphic retrogression and a complex history.

COinS
 
Mar 1st, 9:00 AM Mar 1st, 10:15 AM

Geologic history of a metamorphic core complex in NW Spitsbergen

Criss Library

A Silurian-Devonian aged metamorphic core complex has recently been recognized in northwest Spitsbergen, on the northwest corner of the Barents Shelf. A major tectonic feature of interest is the associated Keisarhjelmen mylonitic detachment zone that is 200 - 500 meters thick. Field work in 2018, 2011 and 2009, revealed a significant northward continuation of the detachment along the west side of Raudfjorden, and is well exposed along the eastern base of Marstranderfjellet. This detachment zone of the core complex separates overlying faulted Silurian - Devonian aged cover rocks from underlying deeper crustal rocks. Within the detachment, strong retrogression is more apparent as one moves from coarsest grained rocks near the bottom to finest near the top of the sequence. This retrogression history is associated with crustal thinning. Various zoning and marginal textures, as well as metamorphic index minerals, were observed in thin section, suggesting a strong metamorphic retrogression and a complex history.