Journal of the Geological Society An Oldest Dryas glacier expansion in the Pelister Mountain (Former Yugoslavian Republic of Macedonia) according to 10Be cosmogenic dating --Manuscript Draft-- Manuscript Number: jgs2017-038R1 Article Type: Research article Full Title: An Oldest Dryas glacier expansion in the Pelister Mountain (Former Yugoslavian Republic of Macedonia) according to 10Be cosmogenic dating Short Title: Cosmogenic age of an Oldest Dryas glacial advance Corresponding Author: Adriano Ribolini, Ph.D Universita degli Studi di Pisa Pisa, ITALY Corresponding Author E-Mail: [email protected] Other Authors: Monica Bini Ilaria Isola Matteo Spagnolo Giovanni Zanchetta Ramón Pellitero Silke Mechernich Raphael Gromig Tibor Dunai Bernd Wagner Ivica Milevski Manuscript Classifications: Dating (radiometric, absolute, etc); Geomorphology Additional Information: Question Response Are there any conflicting interests, No financial or otherwise? Samples used for data or illustrations in Confirmed this article have been collected in a responsible manner Response to Reviewers: Dear Editor, we submit a revised version of the manuscript "An Oldest Dryas glacier expansion in the Pelister mountain (Former Yugoslavian Republic of Macedonia) according to 10Be cosmogenic dating” for consideration by the Journal of the Geological Society. The manuscript has been revised accordingly to the comments of the reviewers. We have uploaded a "reply to reviewers" letter to list the requested changes, and those that we cannot do providing the reasons. In particular we have better detailed the laboratory procedures (reporting chemical analytical results in the supplementary material and an extended description in the Method section). Moreover, the method used for exposure age calculation is now clearer (adding the new Table 2), reporting also the adopted scaling system for spallation and the possible results coming from other models. The procedure to calculate the ELA is now better detailed by adding several lines in the Methods section. The sources of the information necessary to automatically Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation reconstruct the palaeo-glacier have been better acknowledged. All the comments by the Editor have been considered We hope that now the paper may be considered for the publication by the Journal of the Geological Society. Best regards Adriano Ribolini Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation Author cover letter Dear Editor we submit a revised version of the manuscript "An Oldest Dryas glacier expansion in the Pelister mountain (Former Yugoslavian Republic of Macedonia) according to 10Be cosmogenic dating” for consideration by the Journal of the Geological Society. The manuscript has been revised accordingly to the comments of the reviewers. We have uploaded a "reply to reviewers" letter to list the requested changes, and those that we cannot do providing the reasons. In particular we have better detailed the laboratory procedures (reporting chemical analytical results in the supplementary material and an extended description in the Method section). Moreover, the method used for exposure age calculation is now clearer (adding the new Table 2), reporting also the adopted scaling system for spallation and the possible results coming from other models. The procedure to calculate the ELA is now better detailed by adding several lines in the Methods section. The sources of the information necessary to automatically reconstruct the palaeo-glacier have been better acknowledged. All the comments by the Editor have been considered We hope that now the paper may be considered for the publication by the Journal of the Geological Society. Best regards Adriano Ribolini Response to reviewer Reply to the Reviewers Dear Editor, Thank you for the management of our submission and for proving helpful comments and suggestions. In the following pages we reply to all issues raised by the two reviewers and yourself. Reviewer 1: The paper presents interesting results in the dating of three moraine blocks, for which they provide very similar results. Despite the low number of samples, the remarkably homogeneous results obtained allow to include this moraine within a period of widespread glacial advance in the Mediterranean environment and, more generally, on a planetary scale. The work is very well written and very clear. However, it shows some methodological deficiencies, mainly in two fields: A) Chronological analysis of the samples: the manner of taking the samples and the field data is described in great detail, but no details are given of how the geochemical analyses, the calibration method, or the methods for isotope production have been performed. Besides, indicating that "standard laboratory procedures" have been adopted is not sufficient, since these can indeed vary widely. REPLY: The details about laboratory procedures are now included (lines 134-146). Moreover, the details of chemical analytical results are reported in a new Table placed in the supplementary material of the paper Furthermore, the analysis does not describe the values entered in the age calculator used to obtain the ages, nor does it indicate the spallation scaling scheme that has been chosen from the possible ones offered by the age calculator used, nor is it clear what the uncertainty values refer to. REPLY: The values entered in the age calculator are now isolated in Tab 1. The internal uncertainty (analytical uncertainties which are dominated by AMS uncertainties) and the external uncertainty (both analytical and production rate uncertainties) are both indicated in Tab. 2, following Balco et al. 2008 (Quaternary Geochronology 3, 174–195). In the discussion we refer only to the external uncertainty. Moreover, the scaling scheme for spallation is now2 referred at lines 229-230. For this reason, it is essential to clarify all the details of the laboratory analysis carried out and the parameters used, so that the reader can better understand the results. In addition, it is necessary to include a table with all the field and analytical data for the three 10Be samples, and another one with all possible results according to the spallation scaling scheme applied. REPLY: Field and analytical data are now given in the Supplementary material and Tab 1. Tab 2 now include details relative to exposure ages calculation with a constant production rate model (Tab 2a) , scaling system for spallation of Lal (1991) and Stone (2000), and with a time-varying production models (different scaling systems for spallation) (Tab. 2b). B) Calculation of ELAs during the Oldest Dryas in various Mediterranean mountains: The discussion shows the data for the ELA parameter during the Oldest Dryas in various Mediterranean mountains, according to a methodology set out in the corresponding section. In the first place, these data are actually results, so it would be necessary to include them in a separate section in the results chapter, rather than showing them in the discussion. REPLY: It is right, the ELA data were calculated in this study. However, the focus of the paper is on the age and the ELA of this specific moraine in the Pelister area. Similar to what we do for the chronological correlation to other dated moraines in Europe, we prefer to maintain the ELAs comparison across the Mediterranean mountain in the discussion section. But again, the description of the data that have been examined to obtain these results is missing here. Therefore, the reader may begin to have serious doubts as to how these data have been obtained. They do not seem to originate from the previous literature either, since it is not cited, even though there are specific publications where the same methodology has been applied, for example, in Sierra Nevada (see Palma et al., 2017). The doubt becomes greater as few Oldest Dryas glacial landforms have been dated in most of these mountains, which, in most cases, makes it impossible to reconstruct the exact extent of the glaciers during this period. This parameter is fundamental to obtain the ELAs. REPLY: The ELAs were (re)calculated starting from the position of the frontal moraine reported in the original papers, which are all cited in the caption of Figure 7. These refer to dated moraines. As stated in the methodological section, and described in the original GIS tool paper, the glacier reconstruction is based on the position of the frontal moraine and requires a topographic dataset (DTM) as accurate as possible. To reinforce this, a more extended description of the adopted approach is now added to the Method section (lines 176-190). For this reason, it is essential that in addition obtaining results, the manuscript must describe the parameters used to obtain the ELAs analysis in each case, and the source from which these parameters have been taken: are they drawn from the authors' own observations, or do they come from the literature? And, if the latter is the case, they must be cited accordingly. REPLY: Again, the sources are the information (position of the frontal moraine) reported in the corresponding literature (cited in the manuscript). The ways to automatically reconstruct the glacier and to calculate the ELA are described in the paper by Pellitero et al 2015 and Pellitero et al 2016. A description of the GIS tools is reported in the Method section., along with the new added description of the approach adopted to reconstruct the palaeo-glaciers in other Mediterranean mountains (lines 177-190). Reviewer 2: The paper is an important and the first contribution about the deglaciation chronology in Macedonia mountains. Unfortunately the authors used only one spot for filling their goal there. Moreover they used 3 ages only but enough to starts the glaciation chronology puzzle in Macedonia. For now I suggests to use more details data from lake sediments around the spot (Prespa and Maliq). REPLY: The data from nearby Lake Prespa and Maliq provide a good palaeo- environment characterization of the area at the time when the studied palaeo-glacier deposited the dated moraine. This data is referred to in the discussion of our paper.