Structure of the Abercrombie beds south of Reids flat,new South Wales |
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Authors: | Vincent J Morand |
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Institution: | 1. Department of Geology and Geophysics , University of Sydney , Sydney, NSW, 2006, Australia;2. Department of Earth Sciences , Monash University , Clayton, Vic., 3168, Australia |
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Abstract: | The Late Ordovician Abercrombie Beds, south of Reids Flat, New South Wales, and adjacent to the Wyangala Batholith, show evidence of three successive fold episodes. First generation folds are tight to isoclinal, with fold axes ranging from vertical to horizontal and north‐trending, and steep axial‐plane slaty cleavage. Second generation folds are steeply plunging, tight to open with north‐striking axial planes. In pelitic rocks the axial plane structure is a crenulation cleavage which overprints the slaty cleavage. The first two fold episodes were accompanied by greenschist‐facies metamorphism. Granite emplacement occurred prior to the second fold episode. A third deformation was of relatively mild intensity and produced open, north‐trending folds with axial planes dipping moderately to the east, and crenulation cleavage as the axial plane structure in pelitic rocks. These latest folds are correlated with the latest folds in the Abercrombie Beds north of the Abercrombie River. The mapped area has no apparent macroscopic structure and may be considered as a single domain. |
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Keywords: | Abercrombie Beds Wyangala Batholith folds cleavage Ordovician turbidites |
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