Discussion and Conclusion
There are a number of problems with the captions and figures which prevent readers assessing the veracity or otherwise of assertions in the text.
These include:
(1) The time-space plot in Figure 2 is extremely difficult to read as the lettering is too small. It is impossible to assess the various time slices in Figure 3 because the stage information on Figure 2 is unreadable. In addition, it is not clear where some of these columns are located on Figure 3 as they are not labelled nor their position marked on the figure.
This makes it difficult to assess the accuracy of Figure 3 as it is based on the information in this plot.
(2) P.13 Curvature of early Permian units. There is no Permian near point G. Point G could be moved to the NNE into the Werrikimbi Creek area (Hastings 1:250,000 GR6560 000mN, 430 000mE, Figure 3) where there are early Permian rocks (Bourke 1971).
(3) P.12 The legend of Figure 4 does not explain what the red letter R or the green lines correspond to on the map.
(4) P.13; iii. The Merlewood Formation is not present on Figure 4 so it is not possible to assess the veracity of the statement on this formation in this paragraph.
(5) P.14 Most of the formations are not identified in Figure 5B which makes verifying the statements regarding these formations on p.13, extremely difficult. Most readers would not have time to access the relevant literature to enable identification of the relevant formations.
(6) P.12-13 (ii) The units in the Hastings Block corresponding to the lower part of the forearc basin are Tournasian zones 1b and 2, not Pappinbarra Formation or the lower part of the Hyndmans Creek Formation but the Nevann Siltstone and Kindee Conglomerate (Fig. 5B). The Pappinbarra Formation is Tn3, the Hyndmans Creek Formation is Visean and only a small part of the Boonanghi Beds are Tn2. Since most of the Boonanghi Beds are Tournasian 2 to Visean 2 or 3a, we do not know why these beds are coloured as Tournasian 2 (red colour) on Figure 3. This is clearly an incorrect assignment for these beds. The Rollans Road Formation is Fammenian to Tournasian 1b but is coloured red on Figure 3 as though it is all Tournasian zones 1b and 2.
(7) P.16 There is no legend for the different seismic units on Figure 6B. This could have been addressed by annotating these units. Further, the lettering on these units is unreadable and the figure illustrating them is out-of-focus. As result the annotation of the different units and the TWT scale is not readable. Thus there is no way of assessing the statements made on p.15 regarding the geology or the depths of the detachment.
(8) P.19 The identification of formations and the TWT in Figure 8A are difficult to read. In addition, the symbols for each unit and the depth in metres in Figures 8B and C are impossible to discern, apart from the period of their formation. This makes assessing the interpretation presented on p. 18, difficult. Although we accept that the text may provide a reasonable interpretation of these cross sections, this should be able to be tested through the provision of illustrations which are legible and clear.
(9) Roberts et al. (1995) rule out continuity between the Early Carboniferous sequences of the Tamworth Belt and Hastings Block (Boonanghi/Majors Creek Formations). If this is correct, Glen and Roberts (2012) have no basis for delineating an orocline.
(10) P. 13 The text claims the Namurian stage is represented by the Major Creek Formation. However, the rocks of the Namurian stage according to Fig. 5B, do not include the bulk of the Majors Creek Formation which is Visean in age. This is in contradiction to Roberts et al. (1995) who state the Majors Creek Formation is Namurian in age.
(11) P. 24 Figure 10D. No explanation is given in the legend for the WSW trending yellow lines. The legend suggests the different stages of the orocline formation are described in the text. Unfortunately the text does not explain that rectangular bodies of yellow represent Permian deposits or what the diagonal green lines in Figure 10F represent.
In conclusion we do not believe Glen and Roberts (2012) have provided sufficient data to prove that the Manning Orocline exists. Bedding in the subduction-accretion complex rocks in the Mt George area where the hinge zone should be located does not delineate a megafold (Figure 2). Further, the serpentinites are not continuous around both the proposed oroclines and do not have similar ages as would be expected in their model (Figure 1). The eastward ocean-pointing vector suggested for the Hastings/Port Macquarie block area depends on the sequences in both blocks being the same or of comparable ages but they are not. The age of the Majors Creek Formation within the Hastings Block has been changed from Namurian (Roberts et al. 1995) to Visean in Figure 5B without any supporting documentation. This has consequences for the map of chronostratigraphic elements throughout the forearc basin (Figure 3) and hence their interpretation.
The legends for some figures are incomplete (Figures 4, 6B and 7), formations referred to in the text are missing or the lettering in the figure is out-of-focus or has unreadable lettering for different units (Figures 2, 5A, 6B and 8). This makes it extremely difficult to assess the accuracy of statements made in the text.