Joint Inversion of SPREE Receiver Functions and Surface Wave Dispersion Curves for 3-D Crustal and Upper Mantle Structure Beneath the U.S. Midcontinent Rift

G. I. Aleqabi; M. E. Wysession; D. A. Wiens; W. Shen; S. Van der Lee; F. A. Darbyshire; A. W. Frederiksen; S. Stein; D. Jurdy; J. Revenaugh

doi:10.1029/2023JB026771

Joint Inversion of SPREE Receiver Functions and Surface Wave Dispersion Curves for 3-D Crustal and Upper Mantle Structure Beneath the U.S. Midcontinent Rift

G. I. Aleqabi, M. E. Wysession^*, D. A. Wiens, W. Shen, S. Van der Lee, F. A. Darbyshire, A. W. Frederiksen, S. Stein, D. Jurdy, J. Revenaugh

^*Corresponding author for this work

Earth and Planetary Sciences

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

Broadband seismograms from the EarthScope Transportable Array and Superior Province Rifting EarthScope Experiment (SPREE) deployments are used to map the crust and uppermost mantle structures beneath the failed Midcontinent Rift (MCR) of Minnesota/Wisconsin, USA. The results suggest the existence of a variable zone of mafic underplating that is up to 20 km thick (40–60 deep). We jointly invert receiver functions and Rayleigh wave dispersion curves to quantify the region's crustal and mantle shear-wave velocity structure. Basin sediment thicknesses are mildly asymmetric about the rift axis, with thickest regions immediately beneath the rift. 3-D modeling shows anomalous lower crust and crust-mantle transitions beneath the MCR. Sub-MCR crustal thicknesses are generally >50 km with lower crust Vs of 4.0–4.2 km/s. Away from the MCR, the crust is typically ∼40 km thick. Strong variations in apparent crustal thickness are found along the MCR, increasing significantly in places. An additional layer of shear velocities intermediate between typical lower crust and upper mantle velocities (4.1–4.6 km/s) exists beneath most of the MCR which is thickest beneath the rift axis and pinches out away from the rift. This structure corroborates previous proposals of the presence of an underplated layer near the Moho. Results cannot distinguish between different mechanisms of emplacement (e.g., mafic interfingering within a subsequently down-dropped lower crust vs. development of a high-density pyroxenitic residuum at the top of the mantle). Also observed are anomalously high (>4.7 km/s) sub-rift shear-wave velocities at ∼70–90-km depths, suggesting the presence of cold, depleted upper mantle material.

Original language	English (US)
Article number	e2023JB026771
Journal	Journal of Geophysical Research: Solid Earth
Volume	128
Issue number	12
DOIs	https://doi.org/10.1029/2023JB026771
State	Published - Dec 2023

Funding

This study is supported by the NSF Grants EAR-1148088 and EAR-0952345. Our thanks are extended to many national parks and landlords in Canada and USA who allowed us to disturb their yards and temporarily deploy seismometers. Our thanks extend to Trevor Bollmann, Patrick Shore, Emily Wolin, and multiple field assistants for the installation, maintenance, service, and demobilization of the SPREE seismometers. The seismic instruments were provided by the Incorporated Research Institutions for Seismology (IRIS) Portable Array Seismic Studies of the Continental Lithosphere (PASSCAL) Instrument Center and EarthScope USArray Array Operations Facility (AOF). Some figures were made using the GMT software (Wessel et al., 2013). We thank Associate Editor Michael Bostock and two anonymous reviewers for their thorough, insightful, and patient reviews, the changes in response to which significantly improved the readability of this paper. The facilities of IRIS Data Services, and specifically the IRIS Data Management Center (DMC), were used for access to waveforms, related metadata, and/or derived products used in this study. Data from the TA network were made freely available as part of the EarthScope USArray facility, operated by Incorporated Research Institutions for Seismology (IRIS) and supported by the National Science Foundation, under Cooperative Agreements EAR‐1261681. These IRIS TA data can be accessed at IRIS Transportable Array ( 2003 ). The data from the SPREE FA can be obtained at Van der Lee et al. ( 2011 ). This study is supported by the NSF Grants EAR‐1148088 and EAR‐0952345. Our thanks are extended to many national parks and landlords in Canada and USA who allowed us to disturb their yards and temporarily deploy seismometers. Our thanks extend to Trevor Bollmann, Patrick Shore, Emily Wolin, and multiple field assistants for the installation, maintenance, service, and demobilization of the SPREE seismometers. The seismic instruments were provided by the Incorporated Research Institutions for Seismology (IRIS) Portable Array Seismic Studies of the Continental Lithosphere (PASSCAL) Instrument Center and EarthScope USArray Array Operations Facility (AOF). Some figures were made using the GMT software (Wessel et al., 2013 ). We thank Associate Editor Michael Bostock and two anonymous reviewers for their thorough, insightful, and patient reviews, the changes in response to which significantly improved the readability of this paper.

Keywords

Mid-Continent Rift
Moho depth
continental dynamics
continental seismology
subcrustal underplating
surface wave inversion

ASJC Scopus subject areas

Geophysics
Geochemistry and Petrology
Space and Planetary Science
Earth and Planetary Sciences (miscellaneous)

Access to Document

10.1029/2023JB026771

Cite this

Aleqabi, G. I., Wysession, M. E., Wiens, D. A., Shen, W., Van der Lee, S., Darbyshire, F. A., Frederiksen, A. W., Stein, S., Jurdy, D., & Revenaugh, J. (2023). Joint Inversion of SPREE Receiver Functions and Surface Wave Dispersion Curves for 3-D Crustal and Upper Mantle Structure Beneath the U.S. Midcontinent Rift. Journal of Geophysical Research: Solid Earth, 128(12), Article e2023JB026771. https://doi.org/10.1029/2023JB026771

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title = "Joint Inversion of SPREE Receiver Functions and Surface Wave Dispersion Curves for 3-D Crustal and Upper Mantle Structure Beneath the U.S. Midcontinent Rift",

abstract = "Broadband seismograms from the EarthScope Transportable Array and Superior Province Rifting EarthScope Experiment (SPREE) deployments are used to map the crust and uppermost mantle structures beneath the failed Midcontinent Rift (MCR) of Minnesota/Wisconsin, USA. The results suggest the existence of a variable zone of mafic underplating that is up to 20 km thick (40–60 deep). We jointly invert receiver functions and Rayleigh wave dispersion curves to quantify the region's crustal and mantle shear-wave velocity structure. Basin sediment thicknesses are mildly asymmetric about the rift axis, with thickest regions immediately beneath the rift. 3-D modeling shows anomalous lower crust and crust-mantle transitions beneath the MCR. Sub-MCR crustal thicknesses are generally >50 km with lower crust Vs of 4.0–4.2 km/s. Away from the MCR, the crust is typically ∼40 km thick. Strong variations in apparent crustal thickness are found along the MCR, increasing significantly in places. An additional layer of shear velocities intermediate between typical lower crust and upper mantle velocities (4.1–4.6 km/s) exists beneath most of the MCR which is thickest beneath the rift axis and pinches out away from the rift. This structure corroborates previous proposals of the presence of an underplated layer near the Moho. Results cannot distinguish between different mechanisms of emplacement (e.g., mafic interfingering within a subsequently down-dropped lower crust vs. development of a high-density pyroxenitic residuum at the top of the mantle). Also observed are anomalously high (>4.7 km/s) sub-rift shear-wave velocities at ∼70–90-km depths, suggesting the presence of cold, depleted upper mantle material.",

keywords = "Mid-Continent Rift, Moho depth, continental dynamics, continental seismology, subcrustal underplating, surface wave inversion",

author = "Aleqabi, {G. I.} and Wysession, {M. E.} and Wiens, {D. A.} and W. Shen and {Van der Lee}, S. and Darbyshire, {F. A.} and Frederiksen, {A. W.} and S. Stein and D. Jurdy and J. Revenaugh",

year = "2023",

month = dec,

doi = "10.1029/2023JB026771",

language = "English (US)",

volume = "128",

journal = "Journal of Geophysical Research: Solid Earth",

issn = "2169-9313",

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Aleqabi, GI, Wysession, ME, Wiens, DA, Shen, W, Van der Lee, S, Darbyshire, FA, Frederiksen, AW, Stein, S , Jurdy, D & Revenaugh, J 2023, 'Joint Inversion of SPREE Receiver Functions and Surface Wave Dispersion Curves for 3-D Crustal and Upper Mantle Structure Beneath the U.S. Midcontinent Rift', Journal of Geophysical Research: Solid Earth, vol. 128, no. 12, e2023JB026771. https://doi.org/10.1029/2023JB026771

Joint Inversion of SPREE Receiver Functions and Surface Wave Dispersion Curves for 3-D Crustal and Upper Mantle Structure Beneath the U.S. Midcontinent Rift. / Aleqabi, G. I.; Wysession, M. E.; Wiens, D. A. et al.
In: Journal of Geophysical Research: Solid Earth, Vol. 128, No. 12, e2023JB026771, 12.2023.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Joint Inversion of SPREE Receiver Functions and Surface Wave Dispersion Curves for 3-D Crustal and Upper Mantle Structure Beneath the U.S. Midcontinent Rift

AU - Aleqabi, G. I.

AU - Wysession, M. E.

AU - Wiens, D. A.

AU - Shen, W.

AU - Van der Lee, S.

AU - Darbyshire, F. A.

AU - Frederiksen, A. W.

AU - Stein, S.

AU - Jurdy, D.

AU - Revenaugh, J.

PY - 2023/12

Y1 - 2023/12

N2 - Broadband seismograms from the EarthScope Transportable Array and Superior Province Rifting EarthScope Experiment (SPREE) deployments are used to map the crust and uppermost mantle structures beneath the failed Midcontinent Rift (MCR) of Minnesota/Wisconsin, USA. The results suggest the existence of a variable zone of mafic underplating that is up to 20 km thick (40–60 deep). We jointly invert receiver functions and Rayleigh wave dispersion curves to quantify the region's crustal and mantle shear-wave velocity structure. Basin sediment thicknesses are mildly asymmetric about the rift axis, with thickest regions immediately beneath the rift. 3-D modeling shows anomalous lower crust and crust-mantle transitions beneath the MCR. Sub-MCR crustal thicknesses are generally >50 km with lower crust Vs of 4.0–4.2 km/s. Away from the MCR, the crust is typically ∼40 km thick. Strong variations in apparent crustal thickness are found along the MCR, increasing significantly in places. An additional layer of shear velocities intermediate between typical lower crust and upper mantle velocities (4.1–4.6 km/s) exists beneath most of the MCR which is thickest beneath the rift axis and pinches out away from the rift. This structure corroborates previous proposals of the presence of an underplated layer near the Moho. Results cannot distinguish between different mechanisms of emplacement (e.g., mafic interfingering within a subsequently down-dropped lower crust vs. development of a high-density pyroxenitic residuum at the top of the mantle). Also observed are anomalously high (>4.7 km/s) sub-rift shear-wave velocities at ∼70–90-km depths, suggesting the presence of cold, depleted upper mantle material.

AB - Broadband seismograms from the EarthScope Transportable Array and Superior Province Rifting EarthScope Experiment (SPREE) deployments are used to map the crust and uppermost mantle structures beneath the failed Midcontinent Rift (MCR) of Minnesota/Wisconsin, USA. The results suggest the existence of a variable zone of mafic underplating that is up to 20 km thick (40–60 deep). We jointly invert receiver functions and Rayleigh wave dispersion curves to quantify the region's crustal and mantle shear-wave velocity structure. Basin sediment thicknesses are mildly asymmetric about the rift axis, with thickest regions immediately beneath the rift. 3-D modeling shows anomalous lower crust and crust-mantle transitions beneath the MCR. Sub-MCR crustal thicknesses are generally >50 km with lower crust Vs of 4.0–4.2 km/s. Away from the MCR, the crust is typically ∼40 km thick. Strong variations in apparent crustal thickness are found along the MCR, increasing significantly in places. An additional layer of shear velocities intermediate between typical lower crust and upper mantle velocities (4.1–4.6 km/s) exists beneath most of the MCR which is thickest beneath the rift axis and pinches out away from the rift. This structure corroborates previous proposals of the presence of an underplated layer near the Moho. Results cannot distinguish between different mechanisms of emplacement (e.g., mafic interfingering within a subsequently down-dropped lower crust vs. development of a high-density pyroxenitic residuum at the top of the mantle). Also observed are anomalously high (>4.7 km/s) sub-rift shear-wave velocities at ∼70–90-km depths, suggesting the presence of cold, depleted upper mantle material.

KW - Mid-Continent Rift

KW - Moho depth

KW - continental dynamics

KW - continental seismology

KW - subcrustal underplating

KW - surface wave inversion

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U2 - 10.1029/2023JB026771

DO - 10.1029/2023JB026771

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AN - SCOPUS:85180462352

SN - 2169-9313

VL - 128

JO - Journal of Geophysical Research: Solid Earth

JF - Journal of Geophysical Research: Solid Earth

IS - 12

M1 - e2023JB026771

ER -

Joint Inversion of SPREE Receiver Functions and Surface Wave Dispersion Curves for 3-D Crustal and Upper Mantle Structure Beneath the U.S. Midcontinent Rift

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