Conference proceeding
New insights on the geologic framework of Alaska and potential targets of opportunity for future research
American Geophysical Union Fall Meeting, Vol.2015
American Geophysical Union 2015 fall meeting
12/2015
Abstract
Studies the past decade have fundamentally changed our perspective on the Mesozoic and Cenozoic tectonic configuration of Alaska. New concepts include: 1) A link exists between Mesozoic collisional zones, Cenozoic strike-slip fault systems, and active deformation that is related to lithospheric heterogeneities that remain over geologic timescales. The location of the active Denali fault and high topography, for example, is within a Mesozoic collisional zone. Rheological differences between juxtaposed crustal blocks and crustal thickening in this zone have had a significant influence on deformation and exhumation in south-central Alaska. In general, the original configuration of the collisional zone appears to set the boundary conditions for long-term and active deformation. 2) Subduction of a spreading ridge has significantly modified the convergent margin of southern Alaska. Paleocene-Eocene ridge subduction resulted in surface uplift, unconformity development and changes in deposystems in the forearc region, and magmatism that extended from the paleotrench to the retroarc region. 3) Oligocene to Recent shallow subduction of an oceanic plateau has markedly reconfigured the upper plate of the southern Alaska convergent margin. This ongoing process has prompted growth of some of the largest mountain ranges on Earth, exhumation of the forearc and backarc regions above the subducted slab, development of a regional gap in arc magmatism above the subducted slab as well as slab-edge magmatism, and displacement on the Denali fault system. In the light of these new tectonic concepts for Alaska, we will discuss targets of opportunity for future integrated geologic and geophysical studies. These targets include regional strike-slip fault systems, the newly recognized Bering plate, and the role of spreading ridge and oceanic plateau subduction on the location and pace of exhumation, sedimentary basin development, and magmatism in the upper plate.
Details
- Title: Subtitle
- New insights on the geologic framework of Alaska and potential targets of opportunity for future research
- Creators
- Kenneth Daniel Ridgway - Purdue University West LafayetteJ. M TropEmily FinzelP. R BrennanHersh J GilbertL. M Flesch
- Resource Type
- Conference proceeding
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2015
- Conference
- American Geophysical Union 2015 fall meeting
- Publisher
- American Geophysical Union
- Alternative title
- AGU 2015 fall meeting
- Language
- English
- Date published
- 12/2015
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984240903002771
Metrics
2 Record Views