The Carboniferous sequence in the Gloucester‐Myall Lake area, New South Wales

Stratigraphic imprint of the Late Palaeozoic Ice Age in eastern Australia: a record of alternating glacial and nonglacial climate regime

“…Our investigation broadly confirms this interpretation, although we see glacial facies (diamictites) only at the base and top of the unit (Birgenheier 2007). The only other rock unit containing a probable record of this event that we have recognized is the earliest Namurian Yagon Siltstone of the eastern Myall Block (Crane & Hunt 1980;Roberts et al 1991a). An interval in the middle of this unit contains dispersed gravel and glendonites among strongly soft-sediment-deformed mudrocks interpreted as marine slump deposits.…”

“…The termination of glacial conditions at the end of Glaciation C1 is demonstrated by (1) the upward transition from diamictites at the top of the Spion Kop Conglomerate into fluvial sandstones, conglomerates and commonly carbonaceous mudrocks with plant fossils of the Namurian Clifden Formation (Roberts et al 2003), and (2) a thick unit of undeformed, bedded marine mudrocks and sandstones that overlie the slumped interval in the Namurian Yagon Siltstone (Crane & Hunt 1980;Roberts et al 1991a). The same interval is also exposed in the lowermost Seaham Formation of the southern New England Fold Belt, which is composed largely of fluvial conglomerates, particularly in the type section at Seaham (Süssmilch & David 1919;Roberts et al 1991a).…”

Comment on “Orocline‐Driven Transtensional Basins: Insights From the Lower Permian Manning Basin (Eastern Australia)” by White et al. (2016)

“…If they exist, it would be difficult to differentiate them from those formed subsequently during the HBO. We suggest that most faults and associated structures in the Manning Basin were the product of a brittle deformation event that occurred post folding based on the similar attitude of faults and shear joints throughout the area (Figures b–d,) and displacement of axial surface traces by and drag of axial surface traces into conformity with faults (Crane & Hunt, ; Laurie, ; Figure ). This event led to the disassembling of the folded Early Permian sediments in the Manning Basin.…”

“…For example, the sequences in the Gloucester and Myall synclines appear to be unaffected by the formation of the proposed orocline in contrast to the Manning Basin. Further, the Devonian‐Carboniferous sequences are not folded about the proposed orocline axis but maintain a north‐northwest orientation and are folded about north‐northwest axes (Crane & Hunt, ), only changing to a more northwest strike adjacent to the Manning Fault System (Phillips et al, ). This relationship is in stark contrast to the Texas Orocline where Devonian‐Carboniferous subduction‐accretion complex sequences are clearly folded about steeply plunging axes (Lennox & Flood, ; Li et al, ).…”

Stratigraphic revision of the Early Carboniferous Flagstaff formation, southern New England belt, N.S.W

“…Gloucester-Myall Lakes District: In this region the Boolambayte Formation is of Visean age (Crane and Hunt, 1980). The unit is overlain by the Nerong Volcanics which are considered by Roberts and Engel (1980) and Roberts (in press) to be a lateral equivalent of the Gilmore Volcanic Group.…”