Bouchaib Tibari

@article{Sartgou_etal2020,

title = {Late Cenozoic evolution of the Ari`ege River valley (Pyrenees) constrained by cosmogenic 26Al/10Be and 10Be/21Ne dating of cave sediments},

author = {A. Sart\'{e}gou and P. H. Blard and R. Braucher and D. L. Bourl`es and P. Sorriaux and L. Zimmermann and A. Laffitte and B. Tibari and L. Leanni and V. Guillou and A. Bourdet and ASTER team.},

doi = {10.1016/j.geomorph.2020.107441},

year  = {2020},

date = {2020-01-01},

journal = {Geomorphology},

volume = {371},

pages = {107441},

abstract = {Despite increasing knowledge on the orogenic phases of the Pyrenees, the Neogene evolution of the range remains poorly constrained. The central Pyrenees, particularly the Ari`ege River valley and its terrace systems and glacial extensions, are key to reconstructing Pyrenean evolution during the Neogene. However, fewterrace relics remain on the piedmont edges. To overcome this limitation and temporally extend the dataset obtained fromterraces, we focus on alluvium-filled horizontal epiphreatic passages developed in limestone karstic networks. These landforms record the transient position of former local base levels during the process of valley deepening, similar to fluvial terraces. The alluviumfills of the studied caves in the Tarascon-sur-Ari`ege area, in the transition zone between the upper range and the piedmont, therefore enable the reconstruction of the geodynamic evolution of the Ari`ege River valley. All studied caves are developed on at least eight levels. Based on burial durations determined by 26Al/10Be and 10Be/21Ne terrestrial cosmogenic nuclide dating of samples from epiphreatic levels, our results indicate Langhian to Messinian ( 13--5 Ma) incision rates averaging 48 m Myr−1. However, the obtained record does not allow us to accurately retrace the Pliocene evolution of the area due to the lack of known caves at corresponding levels. Moreover, raised local base levels during glacial phases both make the record more complex and call into question the methodological approach in terms of potential internal sediment remobilization and mixing related to implied re-flooding periods.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ternois_etal2019,

title = {Thermochronological evidence of early orogenesis,Eastern Pyrenees, France},

author = {S. Ternois and M. Odlum and M. Ford and R. Pik and D. Stockli and B. Tibari and A. Vacherat and V. Bernard},

doi = {10.1029/2018TC005254},

year  = {2019},

date = {2019-01-01},

journal = {Tectonics},

volume = {38},

pages = {1308--1336},

abstract = {The Pyrenean orogen was generated from late Santonian--early Campanian to middle Miocene by N‐S con-vergence of the Iberian and European plates (Choukroune, 1989 ; Mu~noz, 1992 ; Macchiavelli et al., 2017).External orogenic zones and foreland basins record two distinct periods of low but accelerating tectonicshortening and subsidence, latest Santonian--Danian and Thanetian--Oligocene, separated by a quiet (verylow to near‐zero subsidence) period during the Paleocene (Ford et al., 2016). These two periods arerecognized to be synorogenic and mark two phases of convergence, the second generally recorded asEocene--Oligocene in low‐temperature thermochronology studies. Significantly, the orogentextquoterights three‐phaseconvergence history does not correspond to behavior predicted by foreland dynamic models (Naylor \&Sinclair, 2008 ; Sinclair et al., 2005 ; Sinclair \& Naylor, 2012). While the evolution of crustal thickening, ther-micity, orogen relief, and erosion during the main Eocene--Oligocene collisional phase are well studied andshow a clear link to foreland basin dynamics (Fillon et al., 2013 ; Sinclair, 2011), the early Pyrenean history ofconvergence and the subsequent phase of quiescence are poorly constrained. In particular, there are few dataon the thermal and dynamic behavior of the orogen during the earliest phase of Pyrenean convergence. Therecord of early orogenesis is best observed in the retrowedge where shortening and translation values are low(Naylor \& Sinclair, 2008) and where the main Aptian--Cenomanian rifting phase is preserved. In this paperwe present new zircon and apatite (U‐Th‐Sm)/He (ZHe and AHe, respectively) data from an externalPaleozoic crustal block, Agly‐Salvezines (Figures 1 and 2), in the eastern Pyrenean retrowedge. By integrat-ing these data with new and published geological data, we address the following questions : Can we recog-nize a thermal signature for the onset of Pyrenean convergence and for Paleocene quiescence ? Are earlycrustal thermal events contemporaneous with early foreland tectonic events, or is there a lag time betweenthese two phenomena ? Can we distinguish an early orogenic thermal signature from other thermal eventssuch as those associated with preceding rifting or later collision ?},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Martins_etal2018,

title = {Lake Tauca highstand (Heinrich Stadial 1a) driven by a southward shift of the Bolivian High},

author = {L. Martins and P. H. Blard and J. Lav\'{e} and T. Condom and M. Pr\'{e}maillon and V. Jomelli and D. Brunstein and M. Lupker and J. Charreau and V. Mariotti and B. Tibari and ASTER Team. and E. Davy},

year  = {2018},

date = {2018-01-01},

journal = {Science Advances},

volume = {4},

abstract = {Heinrich events are characterized by worldwide climate modifications. Over the Altiplano endorheic basin (high tropical Andes), the second half of Heinrich Stadial 1 (HS1a) was coeval with the highstand of the giant paleolake Tauca.However, the atmospheric mechanisms underlying this wet event are still unknown at the regional to global scale. We use cosmic-ray exposure ages of glacial landforms to reconstruct the spatial variability in the equilibrium line altitudeof the HS1a Altiplano glaciers. By combining glacier and lake modeling, we reconstruct a precipitation map for the HS1a period. Our results show that paleoprecipitation mainly increased along the Eastern Cordillera, whereas thesouthwestern region of the basin remained relatively dry. This pattern indicates a southward expansion of the easterlies, which is interpreted as being a consequence of a southward shift of the Bolivian High. The results provide a new understanding of atmospheric teleconnections during HS1 and of rainfall redistribution in a changing climate.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Sartgou_etal2018,

title = {Deciphering landscape evolution with karstic networks: A Pyrenean case study},

author = {A. Sart\'{e}gou and D. L. Bourl`es and P. H. Blard and R. Braucher and B. Tibari and L. Zimmermann and L. Leanni and ASTER Team. and G. Auma^itre and K. Keddadouche},

doi = {10.1016/j.quageo.2017.09.005},

year  = {2018},

date = {2018-01-01},

journal = {Quaternary Geochronology},

volume = {43},

pages = {12--29},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Puchol_etal2017,

title = {Variability of magmatic and cosmogenic 3 He in Ethiopian river sands of detrital pyroxenes: Impact on denudation rate determinations},

author = {N. Puchol and P. H. Blard and R. Pik and B. Tibari and J. Lav\'{e}},

doi = {0.1016/j.chemgeo.2016.10.033},

year  = {2017},

date = {2017-01-01},

journal = {Chemical Geology},

volume = {448},

pages = {13--25},

abstract = {In-situ cosmogenic 3He is a robust tool for determining denudation rates or exposure ages of lavas bearing mafic phenocrysts. However, analyses are often complicated by the presence of several helium sources. In particular, in old magmatic rocks with high radiogenic 4He contents, discriminating cosmogenic 3He from magmatic 3He is not straightforward since these varieties may vary largely between aliquots. We sampled sands from the Tekeze and Mile rivers, both draining the basaltic Ethiopian highlands, an area where erosion patterns are intimately linked to the development of the Western Afar margin and to heterogeneous monsoon precipitation. From each river we analyzed textasciitilde15 aliquots of pyroxenes having variable grain sizes (0.3 mm up to N 1 mm). The total 3 He is both higher and more scattered in the bigger grains. Crushing of these largest grains and subsequent melting of the powder tends to produce more homogeneous 3 He values, suggesting that magmatic 3He hosted in inclusions is responsible for most of the inter-aliquot variability. We also performed a Monte Carlo simulation based on a numerical denudation model of the two watersheds. The simulation confirms that cosmogenic3 He variability cannot be responsible for the observed scatter since the cosmogenic 3 He variability is averaged away and unobservable in aliquots of textasciitilde200 grains. A compilation of previously published data also indicates that magmatic helium can be significantly variable, even between pre-crushed aliquots. Hence, magmatic helium, unlike cosmogenic 3 He, is highly variable, even in the case of aliquots of hundreds of grains. We suggest this is due to a strong nugget effect, possibly due to large fluid (or melt)-inclusions contained in phenocrysts.In addition, the fact that small and big grains have comparable radiogenic 4 He concentrations suggests that grain fragmentation during river transport is responsible for the lower magmatic helium content of the smallest grains. Therefore, one should preferably use small grain (0.2--0.5 mm) granulometry for in-situ cosmogenic 3 He analysis in mafic phenocrysts. Using the measured cosmogenic3 He, we calculate basin-averaged denudation rates of 70 textpm 20 and 57 textpm 5mmkyr − 1 , for the Mile and for the Tekeze river, respectively. These values are coherent with long-term denudation rates previously proposed from low-temperature thermochronology.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Vacherat_etal2017,

title = {Rift-to-collision sediment routing in the Pyrenees : A synthesis from sedimentological, geochronological and kinematic constraints},

author = {A. Vacherat and F. Mouthereau and R. Pik and P. Huyghe and J. L. Paquette and F. Christophoul and N. Loget and B. Tibari},

year  = {2017},

date = {2017-01-01},

journal = {Earth-Science Reviews},

volume = {172},

pages = {43--74},

abstract = {Reconstructing long-term drainage evolution in collisional setting is key to deciphering between the drivers controlling landscape and time scales of syn-orogenic sediment transfer processes. Provenance studies in orogenic systems often exploit the geochronological record of past magmatic events in sediments to infer their source rocks. However, detrital age distribution may be difficult to be directly related to a specific source rock because it depends on whole rock composition and a robust stratigraphic and sedimentologic framework. Description of the provenance signal over the orogenic cycle from rift basin to its inversion as an orogenic prism may therefore appear to be a very challenging task. Here, we take advantage of an extensive set of geochronological dates in combination with sedimentological data in well-dated stratigraphic units to resolve uncertainties on grain provenance.We focus on the Pyrenees Mountains that developed in response to the inversion of European and Iberian continental margins from the Late Cretaceous to the Miocene. Inversion of hyper-extended rift basins in the Northern Pyrenees is recorded by specific cooling histories contrasting with the Southern Pyrenees where crustal extension was minor.We review and compile all available detrital thermochronological and geochronological data sets and provide new U/Pb and (U-Th-Sm)/He analyses on detrital zircon grains. This new data set allows us to re-examine the evolution of the sediments routing in the Pyrenees from rift-related Mesozoic basin evolution to tectonic inversion during Cenozoic foreland development. Together with sedimentological and petrographical constraints from syn-rift Mesozoic and syn-orogenic Cenozoic sediments, and within the frame of quantitative kinematic plate reconstructions based on existing rotation data, and balanced cross-sections, we examine the temporal and spatial evolution of sediment routing in the entire Pyrenean realm from rift to collision. Our paleogeographic reconstructions of the sediment dispersal pattern are presented for four key time steps at 100, 70, 55, and 40 Ma, accounting for Iberiatextquoterights plate motion.Early Cretaceous extension on the European margin led to the formation of multiple and narrow basins that were fed locally. This contrasts with the larger-scale pattern of sediment dispersal on the southern Iberia margin. The differences in sediments dispersal are shown to reflect first-order N-S asymmetry of extension. The asymmetry is maintained during the earliest stages of convergence in Late-Cretaceous -- Paleocene. The southern foreland basin exhibits large-scale longitudinal drainage patterns while sediments dispersal in the northern basin is controlled by inherited pre-orogenic E-W-striking basin architecture. In the Paleocene, the southwards migration of thrust sheets and underplating below the Axial Zone led to increasing exhumation at the origin of the emplacement of the first transverse drainage network in the Southern Pyrenees. Changes from dominant longitudinal to transverse drainage in the north occurred in the middle Eocene.Our study emphasizes the role played by the rifted margin on the syn-collisional sediment routing system. We anticipate that this main result could be transposed to other orogens that have resulted from rift basin inversion.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Tibari_etal2016,

title = {An Alternative Protocol for Single Zircon Dissolution with Application to (U-Th-Sm)/He Thermochronometry},

author = {B. Tibari and A. Vacherat and M. Stab and R. Pik and D. Yeghicheyan and P. Hild},

doi = {10.1111/j.1751-908X.2016.00375.x},

year  = {2016},

date = {2016-01-01},

journal = {Geostandards and Geoanalytical Research},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Vacherat_etal2016,

title = {Rift-to-collision transition recorded by tectono-thermal evolution of the northern Pyrenees},

author = {A. Vacherat and F. Mouthereau and R. Pik and N. Bellahsen and C. Gautheron and M. Bernet and M. Daudet and J. Balansa and B. Tibari and R. Pinna Jamme and J. Radal},

doi = {10.1002/2015TC004016},

year  = {2016},

date = {2016-01-01},

journal = {Tectonics},

volume = {35},

pages = {907--933},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Blard_etal2015,

title = {An inter-laboratory comparison of cosmogenic 3 He and radiogenic 4 He in the CRONUS-P pyroxene standard},

author = {P. H. Blard and G. Balco and P. G. Burnard and K. Farley and C. R. Fenton and R. Friedrich and A. J. T. Jull and S. Niedermann and R. Pik and J. M. Schaefer and E. M. Scott and D. L. Shuster and F. M. Stuart and M. Stute and B. Tibari and G. Winckler and L. Zimmermann},

doi = {http://dx.do10.1016/j.quageo.2014.08.004},

year  = {2015},

date = {2015-01-01},

journal = {Quaternary Geochronology},

volume = {26},

pages = {11--19},

abstract = {This study reports an inter-laboratory comparison of the 3 He and 4 He concentrations measured in the pyroxene material CRONUS-P. This forms part of the CRONUS-Earth and CRONUS-EU programs, which also produced a series of natural reference materials for in situ produced 26Al,10Be,14C,21Ne and 36Cl.Six laboratories (GFZ Potsdam, Caltech Pasadena, CRPG Nancy, SUERC Glasgow, BGC Berkeley, Lamont New York) participated in this intercomparison experiment, analyzing between 5 and 22 aliquots each. Intra-laboratory results yield 3He concentrations that are consistent with the reported analytical uncertainties, which suggests that 3He is homogeneous within CRONUS-P. The inter-laboratory dataset (66 determinations from the 6 different labs) is characterized by a global weighted mean of(5.02textpm0.12)x109at g-1 with an overdispersion of 5.6% (2s).4He is characterized by a larger variability than 3He, and by an inter-lab global weighted mean of (3.60textpm0.18)x1013 at g-1(2s) with an overdispersion of 10.4% (2s).There are, however, some systematic differences between the six laboratories. More precisely, 2 laboratories obtained mean 3He concentrations that are about 6%higher than the clustered other 4 laboratories. This systematic bias is larger than the analytical uncertainty and not related to the CRONUS-P material (see Schaefer et al., 2015). Reasons for these inter-laboratory offsets are difficult to identify but are discussed below. To improve the precision of cosmogenic 3He dating, we suggest that future studies presenting cosmogenic 3He results also report the3He concentration measured in the CRONUS-P material in the lab(s) used in a given study},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Blard_etal2014,

title = {Progressive glacial retreat in the Southern Altiplano (Uturuncu volcano, 22textdegreeS) between 65 and 14 ka constrained by cosmogenic 3 He dating},

author = {P. H. Blard and J. Lav\'{e} and K. A. Farley and V. Ramirez and N. Jimenez and L. C. P. Martin and J. Charreau and B. Tibari and M. Fornari},

doi = {10.1016/j.yqres.2014.02.002},

year  = {2014},

date = {2014-01-01},

journal = {Quaternary Science Reviews},

volume = {82},

pages = {209--221},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Poujol_etal2014,

title = {Active tectonics of the Northern Rif (Morocco) from geomorphic and geochronological data},

author = {A. Poujol and J. F. Ritz and A. Tahayt and P. Vernant and M. Condomines and P. H. Blard and J. Billant and L. Vacher and B. Tibari and L. Hni and A. Koulalildrissi},

doi = {10.1016/j.jog.2014.01.004},

year  = {2014},

date = {2014-01-01},

journal = {Journal of Geodynamics},

volume = {77},

pages = {70--88},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Vacherat_etal2014,

title = {Thermal imprint of rift-related processes in orogens as recorded in the Pyrenees},

author = {A. Vacherat and F. Mouthereau and R. Pik and M. Bernet and C. Gautheron and E. Masini and L. Le Pourhiet and B. Tibari and A. Lahfid},

doi = {0.1016/j.epsl.2014.10.014},

year  = {2014},

date = {2014-01-01},

journal = {Earth and Planetary Science Letters},

volume = {408},

pages = {296--306},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Blard_etal2013_2,

title = {Cosmogenic 3He production rate in the high tropical Andes (3800m,20◦S): Implications for the local last glacial maximum},

author = {P. H. Blard and J. Lav\'{e} and F. Sylvestre and C. J. Placzek and C. Claude and V. Galy and T. Condom and B. Tibari},

doi = {10.1016/j.epsl.2013.07.006},

year  = {2013},

date = {2013-01-01},

journal = {Earth and Planetary Science Letters},

volume = {377-378},

pages = {260--275},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Godard_etal2009_2,

title = {Late Cenozoic evolution of the central Longmen Shan, eastern Tibet: Insight from (U-Th)/He thermochronometry},

author = {V. Godard and R. Pik and J. Lav\'{e} and R. Cattin and B. Tibari and J. Sigoyer and M. Pubellier and J. Zhu},

doi = {10.1029/2008TC002407},

year  = {2009},

date = {2009-01-01},

journal = {Tectonics},

volume = {28},

number = {TC5009},

pages = {1--17},

keywords = {},

pubstate = {published},

tppubtype = {article}

}