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Title: The geology of eastern and central Alexander Island, Antarctica
Author: Edwards, C. W.
ISNI:       0000 0001 3438 6480
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 1980
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A brief history of the discovery of Alexander Island, Antarctica, is given. The physiography in the area is consistent with the present polar environment superimposed on an ancient drainage pattern. The LeMay Formation was deposited in a deep water environment and forms a low-grade metamorphic "basement" for younger rocks. Within this formation a neritic fossil assemblage, possibly deposited in an accretionary basin in an arc-trench gap, dates at least part of the formation as late Triassic in age. Polyphase deformation affects most of the LeMay Formation, with non-sequence ophiolites and stratigraphical relationships suggesting that subduction processes were active in the area in pre-Upper Jurassic times. The fossiliferous Upper Jurassic Fossil Bluff Formation is unconformable on the LeMay Formation, but the two formations are usually separated by a large fault zone. A southerly-prograding delta system depositing sediment into a longitudinally-elongated basin is envisaged for the Fossil Bluff Formation. Additionally, large slump structures provide evidence of palaeoslopes within the basin. Both slu~ps and clastic dykes within this thick formation point to an unstable depositional environment. A volcanic sequence of ?Upper Cretaceous age in the Walton Mountains is also unconformable on the LeMay Formation. Calc-alkaline intrusive rocks also exposed in the Walton Mountains may represent plutonic equivalents of the volcanic sequence. Local stratigraphical correlation is possible but correlation with more distant localities is tenuous. The Alexander Island-Palmer Land area gives a good crosssection through a Mesozoic--Cenozoic volcanic arc--fore arc basin-trench system.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Geology