Tectonic affinity of the Mathinna Group in the Lachlan Fold Belt

Linking mainland Australia and Tasmania using ambient seismic noise tomography: Implications for the tectonic evolution of the east Gondwana margin

“…During the last few decades a large number of studies have attempted to correlate and reassemble the continental blocks of mainland southeastern Australia, Tasmania and Antarctica (Sproll and Dietz, 1969;Baillie, 1985;Li et al, 1997;Boger and Miller, 2004;Cawood, 2005;Cayley, 2011;Gibson et al, 2011;White et al, 2013); however, the position of Tasmania in Cambrian reconstructions remains controversial. A diverse range of techniques have so far been exploited to infer information on crustal structure and composition beneath Bass Strait, mainly in studies focusing on similarities recognised in the geology (Crawford and Berry, 1992;Powell and Baillie, 1992;Reed, 2001;Cayley, 2011) and in geophysical, geochemical and other types of data in Tasmania and/or mainland Australia. Geophysical methods include potential field imaging and modelling (e.g., Leaman et al, 1994;Gunn et al, 1997aGunn et al, , 1997bMorse et al, 2009;McLean et al, 2010), seismic reflection profiling (Drummond et al, 2000;Cayley et al, 2011) and seismic tomography (Rawlinson and Kennett, 2008).…”

The significance of a new locality for Monograptus thomasi (Early Devonian) southwest of Beaconsfield, Tasmania, and of the Corn Hill Formation

“…The Bendigo Zone, like the Tabberabbera Zone, exhibits Benambran deformation. Therefore correlation of the Stony Head Sandstone with the Castlemaine Group is not inconsistent with the observations made by Powell & Baillie (1992) and accommodates the key element of Benambran deformation recognised by Reed (2001 b).…”

“…The recognition of Benambran deformation in the Mathinna Supergroup is a key difference between the models of Reed (2001b) and Powell & Baillie (1992). As some earlier authors, Powell & Baillie (1992) correlated the Mathinna Supergroup with the Melbourne Zone in Victoria, a zone in which Benambran deformation is not observed.…”

“…As some earlier authors, Powell & Baillie (1992) correlated the Mathinna Supergroup with the Melbourne Zone in Victoria, a zone in which Benambran deformation is not observed. Reed (2001b) maintained that the deformation of the Tippogoree Group associated with the Benambran Orogeny demonstrated tectonic affiliation of northeastern Tasmania with the Tabberabbera Zone, immediately east of the Melbourne Zone in Victoria, presumably in Late Ordovician and Early Silurian time.…”

“…9) depicted southwesterly directed thrusting to explain the relationships of Palaeozoic rocks near Beaconsfield. The idea of such thrusting was further developed and applied on a broader scale in northern Tasmania by Powell & Baillie (1992 (1992) showed that the two formations of the Tippogoree Group were folded into a large recumbent, east-facing syncline. Reed (200lb) suggested that rocks affected by this fold had one more cleavage than the younger Panama Group close by and quoted Cocker (1982), who suggested an age of 423 ± 22 Ma for the low-grade regional metamorphism of the Turquoise Bluff Slate based on Rb/Sr ratios.…”