Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska
Central Interior Alaska is one of the most seismically active regions in North America, exhibiting a high concentration of intraplate earthquakes approximately 700 km away from the southern Alaska subduction zone. Seismological evidence suggests that intraplate seismicity in the region is not unifor...
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ftdoajarticles:oai:doaj.org/article:4ea1c0f2196f4d149f7b73609398be20 2023-05-15T13:09:47+02:00 Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska Nilesh C. Dixit Catherine Hanks 2021-03-01T00:00:00Z https://doi.org/10.3390/geosciences11030127 https://doaj.org/article/4ea1c0f2196f4d149f7b73609398be20 EN eng MDPI AG https://www.mdpi.com/2076-3263/11/3/127 https://doaj.org/toc/2076-3263 doi:10.3390/geosciences11030127 2076-3263 https://doaj.org/article/4ea1c0f2196f4d149f7b73609398be20 Geosciences, Vol 11, Iss 127, p 127 (2021) potential field modeling interior Alaska transtensional basin foreland basin seismic interpretation Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.3390/geosciences11030127 2022-12-31T13:27:09Z Central Interior Alaska is one of the most seismically active regions in North America, exhibiting a high concentration of intraplate earthquakes approximately 700 km away from the southern Alaska subduction zone. Seismological evidence suggests that intraplate seismicity in the region is not uniformly distributed, but concentrated in several discrete seismic zones, including the Nenana basin and the adjacent Tanana basin. Although the location and magnitude of the seismic activity in both basins are well defined by a network of seismic stations in the region, the tectonic controls on these intraplate earthquakes and the heterogeneous nature of Alaska’s continental interior remain poorly understood. We investigated the crustal structure of the Nenana and Tanana basins using available seismic reflection, aeromagnetic and gravity anomaly data, supplemented by geophysical well logs and outcrop data. We developed nine new two-dimensional forward models to delineate internal geometries and the crustal structure of Alaska’s interior. The results of our study demonstrates a strong crustal heterogeneity beneath both basins. The Tanana basin is a relatively shallow (up to 2 km) asymmetrical foreland basin with its southern, deeper side controlled by the northern foothills of the Central Alaska Range. Northeast-trending left lateral strike-slip faults within the Tanana basin are interpreted as a zone of clockwise crustal block rotation. The Nenana basin has a fundamentally different geometry. It is a deep (up to 8 km), narrow transtensional pull-apart basin that is deforming along the left-lateral Minto Fault. This study identifies two distinct modes of current tectonic deformation in Central Interior Alaska and provides a basis for modeling the interplay between intraplate stress fields and major structural features that potentially influence the generation of intraplate earthquakes in the region. Article in Journal/Newspaper alaska range Alaska Directory of Open Access Journals: DOAJ Articles Northern Foothills ENVELOPE(163.917,163.917,-74.733,-74.733) Geosciences 11 3 127 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
potential field modeling interior Alaska transtensional basin foreland basin seismic interpretation Geology QE1-996.5 |
spellingShingle |
potential field modeling interior Alaska transtensional basin foreland basin seismic interpretation Geology QE1-996.5 Nilesh C. Dixit Catherine Hanks Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
topic_facet |
potential field modeling interior Alaska transtensional basin foreland basin seismic interpretation Geology QE1-996.5 |
description |
Central Interior Alaska is one of the most seismically active regions in North America, exhibiting a high concentration of intraplate earthquakes approximately 700 km away from the southern Alaska subduction zone. Seismological evidence suggests that intraplate seismicity in the region is not uniformly distributed, but concentrated in several discrete seismic zones, including the Nenana basin and the adjacent Tanana basin. Although the location and magnitude of the seismic activity in both basins are well defined by a network of seismic stations in the region, the tectonic controls on these intraplate earthquakes and the heterogeneous nature of Alaska’s continental interior remain poorly understood. We investigated the crustal structure of the Nenana and Tanana basins using available seismic reflection, aeromagnetic and gravity anomaly data, supplemented by geophysical well logs and outcrop data. We developed nine new two-dimensional forward models to delineate internal geometries and the crustal structure of Alaska’s interior. The results of our study demonstrates a strong crustal heterogeneity beneath both basins. The Tanana basin is a relatively shallow (up to 2 km) asymmetrical foreland basin with its southern, deeper side controlled by the northern foothills of the Central Alaska Range. Northeast-trending left lateral strike-slip faults within the Tanana basin are interpreted as a zone of clockwise crustal block rotation. The Nenana basin has a fundamentally different geometry. It is a deep (up to 8 km), narrow transtensional pull-apart basin that is deforming along the left-lateral Minto Fault. This study identifies two distinct modes of current tectonic deformation in Central Interior Alaska and provides a basis for modeling the interplay between intraplate stress fields and major structural features that potentially influence the generation of intraplate earthquakes in the region. |
format |
Article in Journal/Newspaper |
author |
Nilesh C. Dixit Catherine Hanks |
author_facet |
Nilesh C. Dixit Catherine Hanks |
author_sort |
Nilesh C. Dixit |
title |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_short |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_full |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_fullStr |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_full_unstemmed |
Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska |
title_sort |
basement structure and styles of active tectonic deformation in central interior alaska |
publisher |
MDPI AG |
publishDate |
2021 |
url |
https://doi.org/10.3390/geosciences11030127 https://doaj.org/article/4ea1c0f2196f4d149f7b73609398be20 |
long_lat |
ENVELOPE(163.917,163.917,-74.733,-74.733) |
geographic |
Northern Foothills |
geographic_facet |
Northern Foothills |
genre |
alaska range Alaska |
genre_facet |
alaska range Alaska |
op_source |
Geosciences, Vol 11, Iss 127, p 127 (2021) |
op_relation |
https://www.mdpi.com/2076-3263/11/3/127 https://doaj.org/toc/2076-3263 doi:10.3390/geosciences11030127 2076-3263 https://doaj.org/article/4ea1c0f2196f4d149f7b73609398be20 |
op_doi |
https://doi.org/10.3390/geosciences11030127 |
container_title |
Geosciences |
container_volume |
11 |
container_issue |
3 |
container_start_page |
127 |
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1766199075118514176 |