Accreted-Terrane Model

Another objection to the subduction model cited by Weaver et al. (1984) is that the boundary zone of the Lanterman fault does not contain crustal fragments of the subduction-zone complex. In addition, they noted that plutons of the S-type Granite Harbor Intrusives, that 

The accretion model has been supported by many authors, including Bradshaw et al. (1985), Bradshaw (1987,1989), Gibson (1987), Dallmeyer and Wright (1992), as well as by Capponi et al. (1999) who refer to the Lanterman Fault as a suture zone, and by Wodzicki and Robert (1986) in their detailed study of the geology of the Bowers Mountains. 

After the Ross Orogeny, the Wilson Terrane was tectonically deformed by thrust faulting that may have been cansed by the collision of the Bowers and Robertson Bay terranes that also caused uplift of the Wilson HiUs and the Pomerantz Tableland. StiU later, the Rennick Graben formed by normal faulting after relaxation of the compressive stress. 

The Bowers Terrane is located east of the Wilson Terrane and is separated from it by the Lanterman fault zone which has been traced from the Bowers Mountains on the Oates Coast to the Lady Newness Bay on the Borchgrevink Coast of the Ross Sea. The Bowers Terrane appears to be a sliver of a much larger land-mass that originally included an oceanic island-arc system. It is composed of oceanic tholeiites interbed-ded with and overlain by fossiliferous sedimentary rocks that were deposited in a marine environment. The rocks were compressed by westward-directed forces that caused the rocks to be folded and faulted. However, the metamorphic grade is lowermost green-schist facies. The eastern boundary of the Bowers 

Terrane is the Leap Year fault zone which separates it from the Robertson Bay Terrane. 

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The importance of strike-slip motion in the final assanbly of Antarctica is also suggested by the accretion of the Bowers and Robertson Bay terranes to the Wilson ter-rane of northern Victoria Land (Sections 4.4-4.6). Although the provenance of these terranes and the tectonic process that caused them to move into juxtaposition with East Antarctica are as yet unexplained, the tectonic model of Schmidt and Rowley (1986) may offer a suggestion. 

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