skip to main content
Idioma:
Primo Advanced Search
Primo Advanced Search Query Term
Primo Advanced Search prefilters
Busca Simples

Resolving the Cenozoic History of Rock Exhumation Along the Central Rocky Mountain Trench Using Apatite Low‐Temperature Thermochronology

Fraser, K. I. ; Enkelmann, E. ; Jess, S. ; Gilbert, H. ; Grieco, R.

Tectonics (Washington, D.C.), 2021-10, Vol.40 (10), p.n/a [Periódico revisado por pares]

Washington: Blackwell Publishing Ltd

Texto completo disponível

Citações Citado por
  • Título:
    Resolving the Cenozoic History of Rock Exhumation Along the Central Rocky Mountain Trench Using Apatite Low‐Temperature Thermochronology
  • Autor: Fraser, K. I. ; Enkelmann, E. ; Jess, S. ; Gilbert, H. ; Grieco, R.
  • Assuntos: Apatite ; Canadian Cordillera ; Cenozoic ; Continental margins ; Cooling ; Cretaceous ; Dating techniques ; Earth crust ; Eocene ; Faults ; Kinematics ; Miocene ; Mountains ; Omineca Belt ; orogenic collapse ; Palaeocene ; Paleocene ; Radiometric dating ; Rock ; Rocks ; Rocky Mountains ; Temperature ; thermochronology ; Transition zone ; Valleys
  • É parte de: Tectonics (Washington, D.C.), 2021-10, Vol.40 (10), p.n/a
  • Descrição: The Rocky Mountain Trench (RMT) extends through the Canadian Cordillera from the Yukon to northwest Montana. The RMT's impressive length and continuous nature have been interpreted to be the result of faulting, and localized erosion, along a continent‐scale zone of crustal weakness located beneath the RMT, possibly associated with the ancient continental margin. Despite the continuous nature of the RMT, its kinematics vary along strike from dextral strike‐slip faults in the north to normal faults in the south. The central RMT is thought to be the transition between these two structural zones. We use low‐temperature thermochronology to compare the cooling histories across the central RMT in eastern British Columbia. We report apatite fission track ages from 23 samples and apatite (U‐Th)/He ages from 25 samples along with thermal‐history models. Our results reveal three phases of rapid cooling that followed the Cretaceous‐Paleocene cordilleran thrusting in the Eocene, the early–mid Miocene, and from the late Miocene to recent. We find that the Malton Gneiss Complex exhumed as a horst structure 20–10 Ma bounded by the North Thompson Albreda Fault and the RMT. Normal faulting along the NTAF continued in the late Miocene as well as west side down normal faulting along the RMT. Our data suggest that extends along the southern RMT continued northward to at least this portion of the central RMT in multiple episodes during the Cenozoic. We suggest transtension occurred in our study area that was driven by orogenic collapse and lithospheric mantle delamination. Plain Language Summary The Rocky Mountain Trench (RMT) is an impressively long and wide valley in the Canadian Cordillera. It stretches from Montana northward through entire British Columbia and Yukon. This valley follows several underlying faults that caused the displacement of rocks on either side. The southern RMT coincides with normal faults that cause stretching of earth's crust, while the northern RMT follows strike‐slip faults that cause northward motion of the western side of the fault with respect to the eastern side. We investigate the fault motion occurring in the central RMT that is thought to be the transition zone. We collected rocks from both sides of the valley along a 130 km section. The cooling history of these rocks is revealed by using radiometric dating techniques and computer modeling. In the case of extensional faulting, the cooling histories of rocks on either side of the fault are expected to be different. We found several phases of normal faulting occurred in the past 40 million years. In general, the western side of the valley is sliding down from the eastern side of the RMT and causes crustal extension much farther north than previously expected. Key Points We record three phases of rock exhumation along the Rocky Mountain Trench during 45–30 Ma, 20–10 Ma, and since 10 Ma The Malton Gneiss Complex exhumed as a horst structure 20–10 Ma Late Miocene normal faulting occurred along the Rocky Mountain Trench and North Thompson Albreda Fault
  • Editor: Washington: Blackwell Publishing Ltd
  • Idioma: Inglês
Voltar para lista de resultados
Ir para página anteriorAnterior Resultado  8 AvançarIr para próxima página

  • Realização: ABCD-USP USP   Logos de Redes Sociais: Freepik

Buscando em bases de dados remotas. Favor aguardar.