The manuscript gchron2021-45 by M. Sinnesael is a (very) well written, well documented and well-presented case study describing efforts in order to decipher astrocycles from a Lower Paleozoic succession, for which a strong sedimentological background is available from a series a previously published papers. Corresponding to an epicontinental archive (no oceanic record for the considered time interval!), relatively shallow marine deposits are here considered with different, yet combined signatures (depositional facies, pXRF, gamma-ray); the results are of course somewhat disappointing, as the case is as expected challenging. It is good —and rare— to read a paper where the authors remain scientifically ‘honest’, not hiding but highlighting the many problems —even if, in theory, they are well known by the community—, avoiding some fiddling that most often are nonsense (e.g. removing sandstones from the succession, only keeping the clay… and forgetting that each base of a sandstone bed is an erosional surface remobilizing cms to tens of cms of shales).

According to me, the paper could be accepted with only a minor revision required. Below some typos and suggestions for further improving the manuscript and its impact.

Line 42 : pre-Cretaceous (don’t forget the Precambrian record)

Line 68 : Geol. setting and BIOstratigraphy

Line 70: a comma is needed after Fig. 1A

Line 71: on? the cliff

Line 86: a few words about the total related time duration according the chronostratigraphic time scale would here have been welcome (in addition to lines 255-260), to have in mind the temporal significance of the studied interval.

Line 185 : it means that some of the ‘stratigraphic surfaces’ with nodules are hiatial surfaces with zero ‘averaged’ accumulation, indicating also high variations even in shales successions. Need a short discussion?

Line 193… that can fossilize evoluting sedim. facies (?)

Line 198 also mention the usual absence of event beds in the more distal successions

Line 231 : I would have expected a few word about the mineralogy of the placer deposits, either on the basis of thin sections, or XRF analyses: relationships discussed here need to refer to relative contents in zircon, rutile, or monazite (or others)

Line 250 : … is, at this stage, only suggestive…

I would have like to see clear location of placer deposits (e.g., arrows or stars positioned adjacent to the logs)

Lines 284-287 : if the first element (=i) clearly relates to methodological considerations, the second (=ii) is more a cautionary note or at least a welcome reminder.

Line 299: … to have have even more (e.g., Martinez et al., 2016)

Line 318-319: Even though… to be rephrased?

Line 320-320 : this short comment would have merited some more explanations and/or hypotheses. It may suggest that even in offshore shale-dominated successions, remobilization may occur, removing/displacing nodules (then behaving as clats); or that condensation may not be systematically expressed by nodules.

Line 335: wouldn’t be better to write something as (?): “the sequences of similar dominant frequencies are…”

Lines 355-356 : would it need a verb?

Line 364 : The expected changes in sedimentation rates are not counted, in this context, in a few percent, but more likely spread over 2 or 3 orders of magnitude (give references?): this should be better underlined here.

Lines 380-383 : a little too much optimism? Such Zr grains are rare, with a time interval of several million years between crystallization and deposition...

Lines 395-400 : more frequent occurrences of event beds in proximal, sand-dominated interval, which are not or poorly tied to astrochronological controls, might here be emphasized

The conclusion is relatively ‘flat’. The utility and superiority of pXRF appeared clearly demonstrated. It would have been also welcome a statement about potential durations of the Dabard et al.’s (2015) cycles: are they only confirmed? Better characterized? With new proposed durations/controls? Is a revision necessary?

Finally, a short paragraph including a comparison with conclusions of other published Lower Paleozoic case studies (e.g., Long, 2007, Can. J. Earth Sci. 44: 413–431 or Elrick et al., 2014: Geology 2013;41;775-778 among other) or, alternatively, with more recent successions displaying records featured by similar lithologies (e.g., Vaucher et al.  doi.org/10.1038/s41598-021-96372-x ) would have strengthen the paper.