Structure of the Broome Head Metamorphics and related rocks in the Shoalwater Bay area, northern New England Fold Belt
Titel:
Structure of the Broome Head Metamorphics and related rocks in the Shoalwater Bay area, northern New England Fold Belt
Auteur:
Morand, V. J.
Verschenen in:
Australian journal of earth sciences
Paginering:
Jaargang 45 (1998) nr. 1 pagina's 155-167
Jaar:
1998-02
Inhoud:
Medium- to high-grade metamorphic rocks of the Palaeozoic Shoalwater terrane, forming part of the accretionary prism of the New England Fold Belt, crop out at Shoalwater Bay, Queensland. Two formations, the Shoalwater and Townshend Formations, have undergone complex multiple deformation during the Late Permian to Triassic Hunter-Bowen Orogeny. Most generations of structures are correlated from schist on Townshend Island to migmatitic gneiss of the Broome Head Metamorphics on the western shore of Shoalwater Bay. Early accretionary structures (D1) have been obliterated by later deformations D2 to D6, D2 produced tight folds and a metamorphic layering, S2, which is the form surface for many folds. D3 resulted in tight to isoclinal folds which transposed S2 into an S3 layering, such that S2/S3 is the form surface for later folds in much of the Broome Head Metamorphics. D4 has formed map-scale and outcrop-scale folds on Townshend Island and abundant mesoscale folds in the Broome Head Metamorphics. D5 folds are open, trend east and have kilometre-scale wavelengths. D6 folds occur only in the Broome Head Metamorphics, are upright and north-trending, and post-date the fault emplacement of the metamorphics against low-grade rocks to the west. These structures are interpreted as forming during a collisional event which caused the Hunter-Bowen Orogeny.
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