Site index: Suspect and exotic terrane theme. / Some 'light' reading on Alaska. / Some links of possible interest. /

Plate tectonics is a set of ideas that have enjoyed enormous success, and the foundation of that set of ideas can be thought of as a paradigm. That paradigm has expanded to include what might be considered paradigms within the larger paradigm of plate tectonics. The ideas of terrane accretion, that parts of continents are assembled from a mosaic of pieces brought to the continental margin by subduction, but plastered on to the continent instead of recycled into the crust, can be thought of as such a smaller scale paradigm. If there is any place on earth that gave birth to this concept of assembly by terrane accretion it is Alaska.

Key terms: there is a jargon that has developed around this paradigm.

• terrane: fault bounded, nonsubductable, interior rocks have shared geologic history.
• suspect terrane
• exotic terrane
• terrane accretion
• paleowander curves
• outboard
• accretion
• docking
• inboard
• stitching pluton
• sucessor basin or overlap sequence

Types of terranes:

• oceanic plateaus (LIPs)
• oceanic islands, seamounts, guyots.
• island arcs.
• remnant arcs (back arc rift slivers).
• continental fragments/slivers
• ophiolites (oceanic crust of some type.
• composite terranes.
• alternate and less interpretative approach:
  * stratified terranes.
  * disrupted terranes.
  * metamorphic terranes.
  * composite terranes.
  
  

This is just a start - the literature is rich!

• Coming into the Country, John McPhee
• Going to Extremes, Joe McGuiness
• Looking for Alaska, Peter Jenkins

If you find other links of geologic interest for Alaska let me know.

• Plate Tectonics lecture material on suspect and exotic terranes.
• Alaska geologic map.USGSAlaskageomap.gif
• USGS site on 2002 Denali fault earthquake.
• Description of terrane accrection for Yukon area.
• Sand box model of oblique accretion modeled in the context of Alaska.