TY - JOUR A1 - Dielforder, Armin A1 - Frasca, Gianluca A1 - Brune, Sascha A1 - Ford, Mary T1 - Formation of the Iberian-European convergent plate boundary fault and its effect on intraplate deformation in Central Europe JF - Geochemistry, geophysics, geosystems N2 - With the Late Cretaceous onset of Africa-Iberia-Europe convergence Central Europe experienced a pulse of intraplate shortening lasting some 15-20 Myr. This deformation event documents area-wide deviatoric compression of Europe and has been interpreted as a far-field response to Africa-Iberia-Europe convergence. However, the factors that governed the compression of Europe and conditioned the transient character of the deformation event have remained unclear. Based on mechanical considerations, numerical simulations, and geological reconstructions, we examine how the dynamics of intraplate deformation were governed by the formation of a convergent plate boundary fault between Iberia and Europe. During the Late Cretaceous, plate convergence was accommodated by the inversion of a young hyperextended rift system separating Iberia from Europe. Our analysis shows that the strength of the lithosphere beneath this rift was initially sufficient to transmit large compressive stresses far into Europe, though the lithosphere beneath the rift was thinned and thermally weakened. Continued convergence forced the formation of the plate boundary fault between Iberia and Europe. The fault evolved progressively and constituted a lithospheric-scale structure at the southern margin of Europe that weakened rheologically. This development caused a decrease in mechanical coupling between Iberia and Europe and a reduction of compressional far field stresses, which eventually terminated intraplate deformation in Central Europe. Taken together, our findings suggest that the Late Cretaceous intraplate deformation event records a high force transient that relates to the earliest strength evolution of a lithospheric-scale plate boundary fault. KW - intraplate deformation KW - orogeny KW - plate boundary fault KW - plate coupling force KW - Pyrenees KW - lithosphere dynamics Y1 - 2019 U6 - https://doi.org/10.1029/2018GC007840 SN - 1525-2027 VL - 20 IS - 5 SP - 2395 EP - 2417 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Lescoutre, Rodolphe A1 - Tugend, Julie A1 - Brune, Sascha A1 - Masini, Emmanuel A1 - Manatschal, Gianreto T1 - Thermal Evolution of Asymmetric Hyperextended Magma-Poor Rift Systems: Results From Numerical Modeling and Pyrenean Field Observations JF - Geochemistry, geophysics, geosystems N2 - We investigate the thermal and structural evolution of asymmetric rifted margin using numerical modeling and geological observations derived from the Western Pyrenees. Our numerical model provides a self-consistent physical evolution of the top basement heat flow during asymmetric rifting. The model shows a pronounced thermal asymmetry that is caused by migration of the rift center toward the upper plate. The same process creates a diachronism for the record of maximum heat flow and maximum temperatures (T-max) in basal rift sequences. The Mauleon-Arzacq basin (W-Pyrenees) corresponds to a former mid-Cretaceous asymmetric hyperextended rift basin. New vitrinite reflectance data in addition to existing data sets from this basin reveal an asymmetry in the distribution of peak heat (T-max) with respect to the rift shoulders, where highest values are located at the former upper- to lower-plate transition. This data set from the Arzacq-Mauleon field study confirms for the first time the thermal asymmetry predicted by numerical models. Numerical modeling results also suggest that complexities in synrift thermal architecture could arise when hanging-wall-derived extensional allochthons and related T-max become part of the lower plate and are transported away from the upper- to lower-plate transition. This study emphasizes the limitations of the common approach to integrate punctual thermal data from pre-rift to synrift sedimentary sequences in order to describe the rift-related thermal evolution and paleothermal gradients at the scale of a rift basin or a rifted margin. KW - Thermal evolution KW - Asymmetric rifting KW - Numerical model KW - Field analogue KW - Pyrenees KW - Heat flow Y1 - 2019 U6 - https://doi.org/10.1029/2019GC008600 SN - 1525-2027 VL - 20 IS - 10 SP - 4567 EP - 4587 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Caus, Esmeralda A1 - Frijia, Gianluca A1 - Parente, Mariano A1 - Robles-Salcedo, Raquel A1 - Villalonga, Raquel T1 - Constraining the age of the last marine sediments in the late Cretaceous of central south Pyrenees (NE Spain): Insights from larger benthic foraminifera and strontium isotope stratigraphy JF - Cretaceous research N2 - The uppermost Cretaceous (upper Campanian-Maastrichtian) marine deposits of the central south Pyrenees host a rich larger benthic foraminiferal fauna and several rudist-rich levels. These marine deposits are directly overlain by the continental facies of the Aren and Tremp Formations, which are famous for their fossil dinosaur remains. Larger benthic foraminiferal distribution documents an important faunal turnover in all the carbonate platform environments within the photic zone, from open marine to littoral areas. Biostratigraphy indicates that this turnover occurred close to the Campanian-Maastrichtian boundary. This is also confirmed by strontium isotope stratigraphy which indicates an earliest Maastrichtian age for the appearance of the larger benthic foraminiferal assemblage constituted by Lepidorbitoides socialis, Clypeorbis mammillata, Wannierina cataluniensis, Orbitoides gruenbachensis, Siderolites aff. calcitrapoides, Fascispira colomi, Omphalocyclus macroporus and Laffiteina mengaudi. In particular, a numerical age of 71 Ma is obtained for the Hippurites radiosus level, just a few meters below the first continental deposits of the Aren sensu stricto Formation. The youngest marine sediments of the central south Pyrenees are early Maastrichtian in age. This is also an important constraint for the age of the end-Cretaceous dinosaur fossil localities of the Tremp basin. (C) 2015 Elsevier Ltd. All rights reserved. KW - Larger benthic foraminifera KW - Strontium isotope stratigraphy KW - Late Cretaceous KW - Campanian-Maastrichtian boundary KW - Tremp basin KW - Pyrenees KW - NE Spain Y1 - 2016 U6 - https://doi.org/10.1016/j.cretres.2015.05.012 SN - 0195-6671 SN - 1095-998X VL - 57 SP - 402 EP - 413 PB - Elsevier CY - London ER - TY - JOUR A1 - Boix, Carme A1 - Frijia, Gianluca A1 - Vicedo, Vicent A1 - Bernaus, Josep M. A1 - Di Lucia, Matteo A1 - Parente, Mariano A1 - Caus, Esmeralda T1 - Larger foraminifera distribution and strontium isotope stratigraphy of the La Cova limestones (Coniacian-Santonian, "Serra del Montsec", Pyrenees, NE Spain) JF - Cretaceous research N2 - The Upper Cretaceous La Cova limestones (southern Pyrenees, Spain) host a rich and diverse larger foraminiferal fauna, which represents the first diversification of K-strategists after the mass extinction at the Cenomanian-Turonian boundary. The stratigraphic distribution of the main taxa of larger foraminifera defines two assemblages. The first assemblage is characterised by the first appearance of lacazinids (Pseudolacazina loeblichi) and mean-dropsinids (Eofallotia simplex), by the large agglutinated Montsechiana montsechiensis, and by several species of complex rotalids (Rotorbinella campaniola, Iberorotalia reicheli, Orbitokhatina wondersmitti and Calcarinella schaubi). The second assemblage is defined by the appearance of Lacazina pyrenaica, Palandrosina taxyae and Martiguesia cyclamminiformis. A late Coniacian-early Santonian age was so far accepted for the La Cova limestones, based on indirect correlation with deep-water fades bearing planktic foraminifers of the Dicarinella concavata zone. Strontium isotope stratigraphy, based on many samples of pristine biotic calcite of rudists and ostreids, indicates that the La Cova limestones span from the early Coniacian to the early-middle Santonian boundary. The first assemblage of larger foraminifera appears very close to the early-middle Coniacian boundary and reaches its full diversity by the middle Coniacian. The originations defining the second assemblage are dated as earliest Santonian: they represent important bioevents to define the Coniacian-Santonian boundary in the shallow-water facies of the South Pyrenean province. By means of the calibration of strontium isotope stratigraphy to the Geological Time Scale, the larger foraminiferal assemblages of the La Cova limestones can be correlated to the standard biozonal scheme of ammonites, planktonic foraminifers and calcareous nannoplankton. This correlation is a first step toward a larger foraminifera standard biozonation for Upper Cretaceous carbonate platform facies. KW - Larger Foraminifera KW - Biostratigraphy KW - Strontium isotope stratigraphy KW - Coniacian-Santonian boundary KW - Shallow-water carbonates KW - Pyrenees KW - Spain Y1 - 2011 U6 - https://doi.org/10.1016/j.cretres.2011.05.009 SN - 0195-6671 VL - 32 IS - 6 SP - 806 EP - 822 PB - Elsevier CY - London ER - TY - JOUR A1 - Caus, Esmeralda A1 - Parente, Mariano A1 - Vicedo, Vicent A1 - Frijia, Gianluca A1 - Martinez, Ricard T1 - Broeckina gassoensis sp nov., a larger foraminiferal index fossil for the middle Coniacian shallow-water deposits of the Pyrenean Basin (NE Spain) JF - Cretaceous research N2 - The Upper Cretaceous shallow-water carbonates of the Pyrenean Basin (NE Spain) host rich and diverse larger foraminiferal associations which witness the recovery of this group of protozoans after the dramatic extinction of the Cenomanian-Turonian boundary interval. In this paper a new, large discoidal porcelaneous foraminifer, Broeckina gassoensis sp. nov., is described from the middle Coniacian shallow-water deposits of the Collada Gasso Formation, in the Boixols Thrust Sheet. This is the first complex porcelaneous larger foraminifer of the Late Cretaceous global community maturation cycle recorded in the Pyrenean bioprovince. It differs from the late Santonian-early Campanian B. dufrenoyi for its smaller size in A and B generations and the less developed endoskeleton, which shows short septula. Broeckina gassoensis sp. nov. has been widely employed as a stratigraphic marker in the regional geological literature, under the name of "Broeckina", but its age was so far controversial. Its middle Coniacian age (lowermost part of the Peroniceras tridorsatum ammonite zone), established in this paper by strontium isotope stratigraphy, indicates that it took about 5 My after the Cenomanian-Turonian boundary crisis to re-evolve the complex test architecture of larger foraminifera, which is functional to their relation with photosymbiotic algae and K-strategy. KW - Larger Foraminifera KW - Biostratigraphy KW - Strontium isotope stratigraphy KW - Coniacian KW - Pyrenees KW - Spain Y1 - 2013 U6 - https://doi.org/10.1016/j.cretres.2013.08.002 SN - 0195-6671 SN - 1095-998X VL - 45 SP - 76 EP - 90 PB - Elsevier CY - London ER -