CRUSTAL STRUCTURE OF THE NORTHERN YUKON AND MACKENZIE DELTA, NORTHWESTERN CANADA

D M OLEARY, R M ELLIS, R A STEPHENSON, L S LANE, C A ZELT, Randell Stephenson

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Travel time inversion and amplitude forward modeling have been applied to two seismic refraction profiles from the northern Yukon-Mackenzie Delta region of northwestern Canada The two-dimensional crustal P wave velocity models feature a near-surface layer which is 1-7 km thick and has an average velocity of 4 km/s; this overlies three crustal units, each having an average thickness of 11-15 lan and with average velocities of 5.9, 6.1, and 7.1 km/s. The Moho is at similar to 37 km with little relief and overlies an upper mantle with a poorly constrained velocity. Tectonically, the study area lies between cratonic and Cordilleran North America and adjacent Mesozoic polar continental margin. The velocity models clearly illustrate a domainal crustal structure in the study area A cratonic domain is characterized by a middle and lower crust with homogeneous velocities of 6.6-6.8 km/s. The other domain (''Yukon domain'') is characterized by midcrustal velocities near 6 km/s and a lower crustal layer with velocities near 7.1 km/s. The transition zone between these domains is well-defined and is interpreted as a Proterozoic paleocontinental margin, supporting previous interpretations based on geological trends and potential field data. Lateral homogeneity of the crustal velocity structure within Yukon domain supports interpretations that Arctic Alaska was not emplaced into its present position on strike-slip faults. Local variations in lower crustal thickness, together with clear wide-angle Moho reflections, suggest a lower crustal and Moho signature possibly related to rifting, crustal extension, and magmatic intrusion and underplating during the Jura-Cretaceous development of the Arctic Ocean and polar continental margin.

Original languageEnglish
Pages (from-to)9905-9920
Number of pages16
JournalJournal of Geophysical Research
Volume100
Issue numberB6
Publication statusPublished - 10 Jun 1995

Keywords

  • UPPER MANTLE
  • VELOCITY STRUCTURE
  • REFLECTION DATA
  • ARCTIC CANADA
  • ALASKA
  • EVOLUTION
  • BASIN
  • CORDILLERA
  • REGION
  • EAST

Cite this

OLEARY, D. M., ELLIS, R. M., STEPHENSON, R. A., LANE, L. S., ZELT, C. A., & Stephenson, R. (1995). CRUSTAL STRUCTURE OF THE NORTHERN YUKON AND MACKENZIE DELTA, NORTHWESTERN CANADA. Journal of Geophysical Research, 100(B6), 9905-9920.

CRUSTAL STRUCTURE OF THE NORTHERN YUKON AND MACKENZIE DELTA, NORTHWESTERN CANADA. / OLEARY, D M ; ELLIS, R M ; STEPHENSON, R A ; LANE, L S ; ZELT, C A ; Stephenson, Randell.

In: Journal of Geophysical Research, Vol. 100, No. B6, 10.06.1995, p. 9905-9920.

Research output: Contribution to journalArticle

OLEARY, DM, ELLIS, RM, STEPHENSON, RA, LANE, LS, ZELT, CA & Stephenson, R 1995, 'CRUSTAL STRUCTURE OF THE NORTHERN YUKON AND MACKENZIE DELTA, NORTHWESTERN CANADA', Journal of Geophysical Research, vol. 100, no. B6, pp. 9905-9920.
OLEARY DM, ELLIS RM, STEPHENSON RA, LANE LS, ZELT CA, Stephenson R. CRUSTAL STRUCTURE OF THE NORTHERN YUKON AND MACKENZIE DELTA, NORTHWESTERN CANADA. Journal of Geophysical Research. 1995 Jun 10;100(B6):9905-9920.
OLEARY, D M ; ELLIS, R M ; STEPHENSON, R A ; LANE, L S ; ZELT, C A ; Stephenson, Randell. / CRUSTAL STRUCTURE OF THE NORTHERN YUKON AND MACKENZIE DELTA, NORTHWESTERN CANADA. In: Journal of Geophysical Research. 1995 ; Vol. 100, No. B6. pp. 9905-9920.
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abstract = "Travel time inversion and amplitude forward modeling have been applied to two seismic refraction profiles from the northern Yukon-Mackenzie Delta region of northwestern Canada The two-dimensional crustal P wave velocity models feature a near-surface layer which is 1-7 km thick and has an average velocity of 4 km/s; this overlies three crustal units, each having an average thickness of 11-15 lan and with average velocities of 5.9, 6.1, and 7.1 km/s. The Moho is at similar to 37 km with little relief and overlies an upper mantle with a poorly constrained velocity. Tectonically, the study area lies between cratonic and Cordilleran North America and adjacent Mesozoic polar continental margin. The velocity models clearly illustrate a domainal crustal structure in the study area A cratonic domain is characterized by a middle and lower crust with homogeneous velocities of 6.6-6.8 km/s. The other domain (''Yukon domain'') is characterized by midcrustal velocities near 6 km/s and a lower crustal layer with velocities near 7.1 km/s. The transition zone between these domains is well-defined and is interpreted as a Proterozoic paleocontinental margin, supporting previous interpretations based on geological trends and potential field data. Lateral homogeneity of the crustal velocity structure within Yukon domain supports interpretations that Arctic Alaska was not emplaced into its present position on strike-slip faults. Local variations in lower crustal thickness, together with clear wide-angle Moho reflections, suggest a lower crustal and Moho signature possibly related to rifting, crustal extension, and magmatic intrusion and underplating during the Jura-Cretaceous development of the Arctic Ocean and polar continental margin.",
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T1 - CRUSTAL STRUCTURE OF THE NORTHERN YUKON AND MACKENZIE DELTA, NORTHWESTERN CANADA

AU - OLEARY, D M

AU - ELLIS, R M

AU - STEPHENSON, R A

AU - LANE, L S

AU - ZELT, C A

AU - Stephenson, Randell

PY - 1995/6/10

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N2 - Travel time inversion and amplitude forward modeling have been applied to two seismic refraction profiles from the northern Yukon-Mackenzie Delta region of northwestern Canada The two-dimensional crustal P wave velocity models feature a near-surface layer which is 1-7 km thick and has an average velocity of 4 km/s; this overlies three crustal units, each having an average thickness of 11-15 lan and with average velocities of 5.9, 6.1, and 7.1 km/s. The Moho is at similar to 37 km with little relief and overlies an upper mantle with a poorly constrained velocity. Tectonically, the study area lies between cratonic and Cordilleran North America and adjacent Mesozoic polar continental margin. The velocity models clearly illustrate a domainal crustal structure in the study area A cratonic domain is characterized by a middle and lower crust with homogeneous velocities of 6.6-6.8 km/s. The other domain (''Yukon domain'') is characterized by midcrustal velocities near 6 km/s and a lower crustal layer with velocities near 7.1 km/s. The transition zone between these domains is well-defined and is interpreted as a Proterozoic paleocontinental margin, supporting previous interpretations based on geological trends and potential field data. Lateral homogeneity of the crustal velocity structure within Yukon domain supports interpretations that Arctic Alaska was not emplaced into its present position on strike-slip faults. Local variations in lower crustal thickness, together with clear wide-angle Moho reflections, suggest a lower crustal and Moho signature possibly related to rifting, crustal extension, and magmatic intrusion and underplating during the Jura-Cretaceous development of the Arctic Ocean and polar continental margin.

AB - Travel time inversion and amplitude forward modeling have been applied to two seismic refraction profiles from the northern Yukon-Mackenzie Delta region of northwestern Canada The two-dimensional crustal P wave velocity models feature a near-surface layer which is 1-7 km thick and has an average velocity of 4 km/s; this overlies three crustal units, each having an average thickness of 11-15 lan and with average velocities of 5.9, 6.1, and 7.1 km/s. The Moho is at similar to 37 km with little relief and overlies an upper mantle with a poorly constrained velocity. Tectonically, the study area lies between cratonic and Cordilleran North America and adjacent Mesozoic polar continental margin. The velocity models clearly illustrate a domainal crustal structure in the study area A cratonic domain is characterized by a middle and lower crust with homogeneous velocities of 6.6-6.8 km/s. The other domain (''Yukon domain'') is characterized by midcrustal velocities near 6 km/s and a lower crustal layer with velocities near 7.1 km/s. The transition zone between these domains is well-defined and is interpreted as a Proterozoic paleocontinental margin, supporting previous interpretations based on geological trends and potential field data. Lateral homogeneity of the crustal velocity structure within Yukon domain supports interpretations that Arctic Alaska was not emplaced into its present position on strike-slip faults. Local variations in lower crustal thickness, together with clear wide-angle Moho reflections, suggest a lower crustal and Moho signature possibly related to rifting, crustal extension, and magmatic intrusion and underplating during the Jura-Cretaceous development of the Arctic Ocean and polar continental margin.

KW - UPPER MANTLE

KW - VELOCITY STRUCTURE

KW - REFLECTION DATA

KW - ARCTIC CANADA

KW - ALASKA

KW - EVOLUTION

KW - BASIN

KW - CORDILLERA

KW - REGION

KW - EAST

M3 - Article

VL - 100

SP - 9905

EP - 9920

JO - Journal of Geophysical Research

JF - Journal of Geophysical Research

SN - 0148-0227

IS - B6

ER -