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Since the appearance of the first major magnetostratigraphic studies covering the late Neogene of Spain (e.g., Opdyke et al., 1997; Garcés et al., 1998) the number of Spanish continental sections with a correlation to the Geomagnetic Time Scale has steadily grown. Nonetheless, well-calibrated sections with a dense record are still rare, between-basin biostratigraphic correlation is not straightforward, and ages of uncalibrated sites are poorly constrained. Given the overall similarity of rodent assemblages between Iberian basins during the interval MN11–MN17 (9–2 Ma), the definition of a system of Iberian rodent zones for this interval is a logical and necessary step leading to improved correlations. Our revision thus entails the integration of local biozonations into a single Iberian biostratigraphic framework. The inferred series of zone boundary ages are used to improve the age estimates for most Iberian micromammal sites. The chronological backbone in our approach is formed by the available Iberian magnetochronologic records (Teruel, Cabriel, Júcar, Jumilla-La Celia, Fortuna and Guadix-Baza Basins). After analyzing similarities in taxonomic composition and turnover across basins with a defined biozonation (Teruel, Bajo Segura, Alcoy, Granada and Guadix-Baza Basins), 15 Iberian biozones were defined for the 9–2 Ma interval. Age uncertainty intervals for each boundary and for most Iberian micromammal sites were inferred using additional information on local sedimentation and/or evolutionary rates. Among our results are new ages for the latest Tortonian and earliest Messinian (MN12–MN13 transition, 8–7 Ma), a thus far poorly dated interval on the Iberian Peninsula. The new chronology for this interval is based on the integrated stratigraphic records of the Jumilla-La Celia and Teruel Basins. Sections in the Jumilla-La Celia basin (eastern Betic Cordillera; Van Balen et al., 2015) were sampled p

The meandering of alluvial rivers may be forced by normal faulting due to tectonically altered topographic gradients of the river valley and channel at and near the fault zone. Normal faulting can affect river meandering by either instantaneous (e.g. surface-rupturing earthquakes) or gradual displacement. To enhance our understanding of river channel response to tectonic faulting at the fault zone scale we used the physics-based, two-dimensional morphodynamic model Nays2D to simulate the responses of a laboratory-scale alluvial river with vegetated floodplain to various faulting and offset scenarios. The results of a model with normal fault downstepping in the downstream direction show that channel sinuosity and bend radius increase up to a maximum as a result of the faulting-enhanced valley gradient. Hereafter, a chute cutoff reduces channel sinuosity to a new dynamic equilibrium value that is generally higher than the pre-faulting sinuosity. A scenario where a normal fault downsteps in the upstream direction leads to reduced morphological change upstream of the fault due to a backwater effect induced by the faulting. The position within a meander bend at which faulting occurs has a profound influence on the evolution of sinuosity; fault locations that enhance flow velocities over the point bar during floods result in a faster sinuosity increase and subsequent chute cutoff than locations that enhance flow velocity directed towards the floodplain. This upward causation from the bend scale to the reach and floodplain scale arises from the complex interactions between meandering and floodplain and the nonlinearities of the sediment transport and chute cutoff processes. Our model results provide a guideline to include process-based reasoning in the interpretation of geomorphological and sedimentological observations of fluvial response to faulting. The combination of these approaches leads to better predictions of possible effects of faulting on alluvial river meand

Faults in the Roer Valley Rift System (Netherlands, Belgium, and Germany) act as barriers to lateral groundwater flow in unconsolidated sedimentary aquifers. This causes a cross-fault groundwater-level step of up to several metres. Using a dataset obtained through 5 years of high-frequency monitoring, the effect of fault-zone permeability, precipitation and evapotranspiration on cross-fault groundwater-level steps is studied at two sites situated across the Peel Boundary Fault. Hydraulic conductivity values at the fault are 1–3 orders of magnitude lower than that of similar lithologies away from the fault, indicating that fault displacement has a significant impact on groundwater flow. The influence of precipitation and evapotranspiration on fault-zone hydrology is inferred from water-table fluctuations over short distances across the fault. On the foot wall, the water table is nearer to the surface and displays a shorter level range with a spiky temporal variability. On the hanging wall, a deeper water table is sloping away from the fault and shows a wider level range with a smoother temporal variability. The observed groundwater level fluctuations are attributed mainly to precipitation and evapotranspiration dynamics. At a larger spatial scale, the 5-year-average cross-fault groundwater-level steps at the two sites are 1.59 and 1.39 m. At a smaller scale, the cross-fault groundwater-level step is much less because of the rising water table towards the fault on the hanging wall. At the smallest scale, just across the fault zone, the groundwater level step is around 0.2 m, indicating that the fault is semi-impermeable.

Due to canal-digging activities in 2011 and 2014, two small and one large temporary exposure, all ranging from 4 to 5 m in depth, were studied with respect to the sedimentology and structural geology, in the glacial ridge of Midwolda, Groningen, the Netherlands. The lowermost unit consists of clay of Elsterian age and is composed of glaciolacustrine and turbiditic deposits (Peelo Formation). These show synsedimentary deformations due to loading, as well as post-sedimentary Saalian glaciotectonic deformations, consisting of folding, and faulting structures. The overlying Saalian till sequence consists of two main units. The lower unit, with clear features of a subglacial deformation zone (e.g. lateral heterogeneity), has a local origin and strongly resembles the underlying Elsterian clay. Glacial tectonic and morphological observations indicate a primary NE-SW ice-flow direction. The second till layer has a sandy texture and high crystalline gravel content, while glacial-tectonic indicators point to a NW-SE ice-flow direction. The deformation of the till layers has caused a repetition and mixing of till layers, due to the last ice movement. The NW-SE ice movement is supported by the morphology as well as data from erratic gravel counts. Correlation with geological cross-sections strongly suggests regional subsurface control on ice-sheet behaviour.