Publisher’s note: the supplement to this comment was edited on 23 October 2023. The adjustments were minor without effect on the scientific meaning.

I am submitting a Review plus annotated copies of ms and Supplementary File.

Manuscript by Ana Fonseca, Simon Nachtergaele, Amed Bonilla, Stijn Dewaele, Johan De Grave

https://doi.org/10.5194/egusphere-2023-2113 Preprint. Discussion started: 27 September 2023

Dear Editor and authors, 

first, I really thank the Editor for choosing me to review the manuscript by Fonseca et al. I really enjoyed reading it and I also admit I learned a lot.

Please, see my comments for this manuscript are provided in two files. Here, you find a formal summary of my major comments and concerns, and a marked-up version of the manuscript sent to me for review (PDF document). Both files contain similar comments/questions/suggestions. Still, comments on figures and some text corrections are better explained in the PDF document, so please ensure that both are reviewed during revisions. 

General comments

The manuscript objectives are well defined but sometimes I believe the reader needs some more information or better displayed. In the reviewed PDF I have noted a few times the need to add more references. In these comments, I suggest some papers that might be included in the manuscript.

Figure 1

In general, this figure is too crowded with information. I strongly suggest to divide it in three.

1A: DEM + Geological and geographical elements. Basins are not well highlighted if shown only with isobaths. For example, the lines behind Tukutu (or Takutu?) Basins are barely visible. If you divide this figure in two you have a cleaner DEM to put geological information on.

1B: DEM at the same scale as 1A but with only geochronological provinces, perhaps shown with polygons in different colours.

1C: geological profile. Check carefully that the geology in the profile and in the map match 100%.

In the Geological Setting you have a long description based on just two references. I believe you can integrate more bibliography. Also, you always cite fig. 1 but in that figure, it is not possible to unravel all the history you are describing.

In the main text, you cite Fig. 3 before Fig. 2. Switch the order of the figures If you need to.

Figure 2

What is the basement you have sampled? You show stars for ZUPb but your study is actually focused on AFT samples, thus they need to be put on this figure too.

Figure 4

This image is really confusing to understand... Why don't you use colour shades to show the subsidence values along the basin? Also, creating a bigger block diagram including the study area would help the reader a lot.

Figure 5

I do not fully agree with that. Your Fig. 5 shows a high peak around 1 Ga in the Neogene units. However, if you do not show the values on the y-axis you cannot compare the relative contributions from different histograms, thus your sentence here cannot be supported.

Figure 6

These pie charts need to be larger because they show the data you discuss, so they are the most important thing in the figure. This figure is essentially a paleogeography, it is important to write – at least in the caption – the geological time the map refers to.

The modelling chapter is an important part of this paper. You also use an uncommon and interesting approach which deserves to be better illustrated. I suggest moving some figures from the supplemental material to the main manuscript to help the reader visualize the differences among the models’ results. Reading only their descriptions can be confusing.

I see your Dpar measurements are values and sometimes very low. Do you think the differences in AFT ages and lengths are only due to the differences in thermal history and may not be influenced by the nature of the apatite itself? Perhaps you should detail this a little more.

I appreciate you were careful to not stress any conclusions for T< 60 and Cenozoic geological history.

However, more and more scientists agree on the fact that one thermochron. system only can lead to a partial T-t history, and the use of two dating methods is always advised. Do you think you can use data from published works?

Also, you report ages from 97 to 177 Ma, but you are confident in describing the area with a homogeneous rock cooling history. I guess you need to explain this a little deeper.

In the discussion section, I would also mention that cooling ages may also depend on the volcanic activity at the plate margin. Many passive margins are volcanic and offshore they show very interesting - and poorly constrained - Seaward Dipping Reflectors which are the product of onshore volcanic complexes today completely eroded. This means that we constantly underestimate the geothermal gradient (and its variation) and the possible reheating cycles of the margins which involves an additional complication to the T-t paths.

I still strongly support the work by Fonseca and coauthors. Their findings are needful for the scientific community working on Paleozoic paleogeography. I hope the authors will consider my comments as constructive suggestions; my notes have the only purpose of improving the manuscript to be more appealing to a larger audience.

Sincerely,

Chiara Amadori, PhD

Research Fellow

University of Pavia, Italy