[citation needed] This process is operative beneath and behind the inner walls of oceanic trenches (subduction zone) where slices of oceanic crust and mantle are ripped from the upper part of the descending plate and wedged and packed in high pressure assemblages against the leading edge of the other plate.
The simplest form of this type of obduction may follow from the development of a subduction zone near the continental margin.
According to the rock assemblage as well as the complexly deformed ophiolite basement and arc intrusions, the Coastal Complex of western Newfoundland may well have been formed by this mechanism.
This concept has subsequently been replaced by hypotheses that advocate subduction of the continental margin beneath oceanic lithosphere.
Many ophiolite complexes were emplaced as thin, hot obducted sheets of oceanic lithosphere shortly after their generation by plate accretion.
[8] Dewey and Bird[12] suggest that a common form of ophiolite obduction is related to the closure of rear-arc marginal basins and that, during such closure by subduction, slices of oceanic crust and mantle may be expelled onto adjacent continental forelands and emplaced as ophiolite sheets.
This thin lithosphere may preferentially fail along gently dipping thrust surface if a compressional stress is applied to the region.
Following total subduction of an oceanic tract, continuing convergence may lead to a further sequence of intra-continental mechanisms of crustal shortening.
The Klamath Mountains of northern California contain several obducted oceanic slabs, most famously the Coast Range Ophiolite.