Abstract
Low grade metasediments and metavolcanics of the Hill End Synclinorial Zone within the Rockley district, NSW have experienced two phases of macroscopic folding (D1and D2), both of which are post-latest Silurian in age. No hiatus is evident between D1and D2. D1 produced large Fi folds (λ/2 usually > 2 km) lacking mesoscopic elements and having variable axial trends. D2was associated with the development of regional slaty cleavage (S2) and mesoscopic folds which are parasitic on plunging macroscopic F2folds (λ/2=0.4-2 km). D2strain is variable, being most intense in the north of the district where slaty cleavage and tight mesoscopic F2folds are well developed, and weakest in the south where mesoscopic folds are absent or usually gentle and cleavage is often feebly developed even in mica-rich rocks, which are stratigraphic equivalents to slates and schists in the north. The F1fold mechanism may involve multiple folding, simultaneous folding in more than one direction, or complex buckling of layers of variable thickness. D1and D2are tentatively correlated with folding events elsewhere in the Hill End Synclinorial Zone.
Original language | English |
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Pages (from-to) | 451-468 |
Number of pages | 18 |
Journal | Australian Journal of Earth Sciences |
Volume | 36 |
Issue number | 3 |
DOIs | |
Publication status | Published - Sept 1989 |
Externally published | Yes |
Keywords
- Lachlan Fold Belt tectonics
- Layer thickness variations
- Rockley district
- Superposed folds
ASJC Scopus subject areas
- Earth and Planetary Sciences (miscellaneous)
- General Earth and Planetary Sciences