Details

Autor(en) / Beteiligte

• Yan, J.
• Lennox, P. G.
• Offler, R.

Titel

The structural evolution of the Northern Hastings Block and southern Nambucca Block, southern New England Orogen, eastern Australia

Ist Teil von

• Australian journal of earth sciences, 2017-10, Vol.64 (7), p.871-887

Ort / Verlag

Hoboken: Taylor & Francis

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Taylor & Francis

Beschreibungen/Notizen

• The Hastings Block is a weakly cleaved and complexly folded and faulted terrain made up of Devonian, Carboniferous and Permian sedimentary and volcanic rocks. The map pattern of bedding suggests a major boundary exists that divides the Hastings Block into northern and southern parts. Bedding north of this boundary defines an upright box-like Parrabel Anticline that plunges gently northwest. Four cleavage/fold populations are recognised namely: E-W-striking, steeply dipping cleavage S 1 that is axial surface to gently to moderately E- or W-plunging; F 1 folds that were re-oriented during the formation of the Parrabel Anticline with less common N-S-trending, steeply dipping cleavage S 2 , axial surface to gently to moderately N-plunging F 2 folds; poorly developed NW-SE-striking, steeply dipping cleavage S 3 axial surface to mesoscopic, mainly NW-plunging F 3 folds; and finally , a weakly developed NE-SW-striking, steeply dipping S 4 cleavage formed axial surface to mainly NE-plunging F 4 . The Parrabel Anticline is considered to have formed during the D 3 deformation. The more intense development of S 2 and S 3 on the western margin of the Northern Hastings Block reflects increasing strain related to major shortening of the sequences adjacent to the Tablelands Complex during the Hunter-Bowen Orogeny. The pattern of multiple deformation we have recorded is inconsistent with previous suggestions that the Hastings Block is part of an S-shaped orocline folded about near vertically plunging axes.