Date of Award

6-2022

Degree Name

Doctor of Philosophy

Department

Geological and Environmental Sciences

First Advisor

Michelle Kominz, Ph.D.

Second Advisor

William Sauck, Ph.D.

Third Advisor

Peter Voice, Ph.D.

Fourth Advisor

Jacob Thacker, Ph.D.

Keywords

Backstripping, Canterbury Basin, epeiorgenic, New Zealand, slab graveyard, uplift

Abstract

Cored marine sediments from Canterbury Basin Integrated Ocean Drilling Program (IODP) Expedition 317 shelf sites U1351, U1353, and upper slope Site U1352 have been resampled with emphasis on benthic foraminifera from the Late Eocene to Late Pliocene. These new data coupled with paleo water-depth and age data from the nearby Clipper-1 petroleum exploration well, are used to develop a 1-dimensional basin subsidence model for the Canterbury Basin. Our model indicates there was widespread epeirogenic uplift of 890  350m, in the mid-Neogene (5.9-3.7 million years ago), which took place during concomitant ultramafic volcanism. Close association of uplift and volcanism could suggest a causal relationship. We hypothesize that the epeirogenic uplift and concomitant ultramafic volcanism of the Canterbury Basin was caused by delamination of the mantle lithosphere, when negatively buoyant ultramafics (eclogite-rich peridotite) detached along or below the Moho and sank into the mantle. The presence of negatively buoyant ultramafic rocks is attributed to metamorphism of the mantle lithosphere, resulting from volatiles escaping from a deeply buried subduction slab graveyard.

Access Setting

Dissertation-Open Access

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