|The manuscript "Plio-Quaternary tectonic evolution of the southern margin of the|
Alboran Basin (Western Mediterranean)" presents new high quality and well interpreted seismic sections of the southwestern Alboran basin that deserve publishing. Although, I find that the results obtained from the interpretation are not justified entirely. To start with, the data presented is mostly post-late Miocene and thus, results written in the abstract corresponding to the earlier Miocene evolution are not supported by the data presented here.
No evidence of extensional or strike-slip structures active before the Tortonian are shown in this manuscript. Furthermore, the western Alboran basin, the object of this work, is not a back-arc basin. It is located in a fore-arc position, to the west of the volcanic arc (Booth-Rea et al., 2007; 2018; Gómez de la Peña et al., (2018).
Booth-Rea, G., C. Ranero, J. M. Martínez-Martínez, and I. Grevemeyer (2007), Crustal types and Tertiary tectonic evolution of the Alborán sea, western Mediterranean, G-Cubed, 8, Q10004, doi: 10010.11029/12007GC001661.
Booth-Rea, G., C. R. Ranero, and I. Grevemeyer (2018), The Alboran volcanic-arc modulated the Messinian faunal exchange and salinity crisis, Scientific Reports, 8.
de la Peña, L. G., C. R. Ranero, and E. Gracia (2018), The Crustal Domains of the Alboran Basin (Western Mediterranean), Tectonics, 37(10), 3352-3377.
In the abstract please be more precise with the Tortonian age. The Tortonian represents a long time period between 11.6 and 7.2 Ma. Furthermore, the Tortonian was the period with largest tectonic subsidence (Rodríguez-Fernández et al., 1999) and arc related magmatism in the Alboran basin and also onshore (e.g. Duggen et al., 2008). Tectonic subsidence that was mostly related to extensional tectonics (Booth-Rea et al., 2004a, Giaconia et al., 2014).
Booth-Rea, G., J. M. Azanon, and V. Garcia-Duenas (2004), Extensional tectonics in the northeastern Betics (SE Spain): case study of extension in a multilayered upper crust with contrasting rheologies, J Struct Geol, 26(11), 2039-2058.
Duggen, S., K. Hoernle, A. Klugel, J. Geldmacher, M. Thirlwall, F. Hauff, D. Lowry, and N. Oates (2008), Geochemical zonation of the Miocene Alboran Basin volcanism (westernmost Mediterranean): geodynamic implications, Contrib Mineral Petr, 156(5), 577-593.
Giaconia, F., G. Booth-Rea, J. M. Martínez-Martínez, J. M. Azañõn, F. Storti, and A. Artoni (2014), Heterogeneous extension and the role of transfer faults in the development of the southeastern Betic basins (SE Spain), Tectonics, 33(12), 2467-2489.
Rodríguez Fernández, J., M. C. Comas, J. Soria, J. A. Martín Pérez, and J. I. Soto (1999), The Sedimentary Record of the Alboran Basin: an Attempt at Sedimentary Sequence Correlation and Subsidence Analysis, in Proc. ODP Sci. Results, edited by R. Zahn, M. C. Comas and A. Klaus, pp. 69-76.
In the abstract, conclusions and discussion I miss other alternative tectonic mechanism for explaining the evolution of your studied region.
Is there no other tectonic mechanism acting in the area apart from plate convergence? Many papers confer a role in the tectonics of the Western Alboran region to the underlying Alboran slab (e.g. González-Castillo et al., 2015; Mancillla et al., 2015; Heit et al. 2017, Spakman et al., 2018; Capella et al., 2019; Sun and Bezada, in press). Other alternatives to only plate convergence should be discussed in the paper.
Gonzalez-Castillo, L., J. Galindo-Zaldivar, M. C. de Lacy, M. Borque, F. J. Martinez-Moreno, J. A. Garcia-Armenteros, and A. J. Gil (2015), Active rollback in the Gibraltar Arc: Evidences from CGPS data in the western Betic Cordillera, Tectonophysics, 663, 310-321.
Heit, B., Mancilla, F. D. L., Yuan, X., Morales, J., Stich, D., Martín, R., & Molina‐Aguilera, A. (2017). Tearing of the mantle lithosphere along the intermediate‐depth seismicity zone beneath the Gibraltar Arc: The onset of lithospheric delamination. Geophysical Research Letters, 44(9), 4027-4035.
Mancilla, F. L., G. Booth-Rea, D. Stich, J. V. Pérez-Peña, J. Morales, J. M. Azañón, R. Martin, and F. Giaconia (2015), Slab rupture and delamination under the Betics and Rif constrained from receiver functions, Tectonophysics, 663, 225-237.
Spakman, W., Chertova, M. V., van den Berg, A., & van Hinsbergen, D. J. (2018). Puzzling features of western Mediterranean tectonics explained by slab dragging. Nature Geoscience, 11(3), 211-216.
Sun, M., & Bezada, M. Seismogenic necking during slab detachment, evidence from relocation of intermediate depth seismicity in the Alboran slab. Journal of Geophysical Research: Solid Earth.
The Alboran tectonic domain has been recently redefined as only the upper plate of the Betic-Rif internal zones (Booth-Rea et al., 2015; Jabaloy et al., 2018). Most of the basement of your studied region probably does not correspond to the Alboran domain, being formed by para-autochthonous low-grade metamorphic rocks of the Maghrebian Rif units or by volcanic accretion (e.g. Azdimousa et al., 2018; Gomez de la Peña et al., 2018).
Azdimousa, A., A. Jabaloy-Sánchez, P. Münch, J. M. Martínez-Martínez, G. Booth-Rea, M. Vázquez-Vílchez, L. Asebriy, J. Bourgois, and F. González-Lodeiro (2018), Structure and exhumation of the Cap des Trois Fourches basement rocks (Eastern Rif, Morocco), J Afr Earth Sci, in press.
Slab tearing or detachment in the region occurred during the Late Miocene until Recent (e.g. García-Castellanos and Villaseñor, 2009; Mancilla et al., 2015), not during the Early Miocene.
This discussion is not exactly a discussion. For it to be so, you need to discuss other alternative ideas to yours, which you have previously mentioned in the introduction. Here there is no mention to the tectonic effects that a deep slab could have in your studied area, for example. Please rewrite this section citing and considering other possibilities, instead of only considering plate convergence as the sole driver for deformation in the region.
Please see more detailed comments in the attached annotated PDF file.
Guillermo Booth Rea