Geological and isotopic constraints on the structure of the Bilbao anticlinorium (Basque–Cantabrian basin, North Spain)

However salt has a viscous rheology, overburden rocks adjacent to salt diapirs have a brittle rheology. Evidence of deformation within the overburden has been described from diapirs worldwide. Gravitydriven deposits are also present along the flanks of several diapirs. The well-known example from the La Popa Basin in northern Mexico shows that such deposits may be organized into halokinetic sequences. This leads to several questions: (i) How does diapir growth contribute to overburden deformation? (ii) Are halokinetic sequence models valid for other areas beyond the La Popa Basin. The Bakio diapir and its well-exposed overburden in Basque Country, Spain provides key elements to address these questions. The Bakio diapir consists of Triassic red clays and gypsum and is flanked by synkinematic middle to upper Albian units that thin towards the diapir. The elongate diapir parallels the Gaztelugatxe normal fault to the NE: both strike NE-SW and probably formed together during the middle Albian, as synkinematic units onlap the fault scarp. The diapir is interpreted as a reactive diapir in response to middle Albian motion on the Gaztelugatxe fault. The rate of salt rise is estimated to be about 500 m Myr À1 during this passive stage. During Late Albian, the diapir evolved passively as the Gaztelugatxe fault became inactive. Synkinematic units thinning towards the diapir, major unconformities, slumps and other gravity-driven deposits demonstrate that most deformation related to diapir growth occurred at the sea floor. Halokinetic sequences composed of alternating breccias and fine-grained turbidites recorded cyclic episodes of diapir flank destabilization. This work provides insights into drape fold and halokinetic sequence models and offers a new simple method for estimating rates of diapir growth. This method may be useful for outcrop studies where biostratigraphical data are available and for other passive diapirs worldwide.

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“…Geological map of the B asque– C antabrian B asin (simplified from Ábalos et al ., ). BCB : Basque–Cantabrian Basin.…”

Section: Geological Settingmentioning

confidence: 97%

“…At present, the Basque–Cantabrian Basin corresponds to the westernmost part of the Pyrenean realm (Fig. ), with limited N–S shortening estimated between 25 km (Gómez et al ., ) and 40–50 km (Ábalos et al ., ).…”

Section: Geological Settingmentioning

confidence: 97%

Sedimentary and structural record of the Albian growth of the Bakio salt diapir (the Basque Country, northern Spain)

et al. 2014

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“…1). In this part, anhydrite and gypsum deposits alternate with silt, mudstone, sandstone and limestones in Wealden Facies evaporites (IGME, 1987;Ábalos et al, 2008;Iribar and Ábalos, 2011 occupy the core of major geological structures in this part of the Basque-Cantabrian basin has prevailed during the last decades (Ábalos et al, 2008). Occurrence of gypsum in different rock series (Early Cretaceous Wealden Facies and Triassic Keuper facies) was recognised in several works of the area (tunnel excavation, Peña and Rodenas, 2011;exploration wells).…”

Section: Study Areamentioning

confidence: 99%

“…The most reducing conditions were measured at E1 (−106 mV) during the drier season of October 2011, when discharge at the gauging station was very low (1.57 m 3 s −1 ). The highest values of electric conductivity (1109-2570 μS/cm) and most of the major ions (Ca 2+ , Mg +2 , Na + , K + , Si, Cl − and SO 4 2 − , Table 2) are found in headwaters (D1, D2 and M1) which could be influenced by groundwater circulation from rocks holding evaporites (Ábalos et al, 2008;Iribar and Ábalos, 2011). Diffuse discharge of groundwater flows from evaporitic deposits, with high content of Na + , Cl − and SO 4 2−…”

Section: Spatial and Temporal Distributionmentioning

confidence: 99%

Influence of anthropogenic inputs and a high-magnitude flood event on metal contamination pattern in surface bottom sediments from the Deba River urban catchment

Martínez‐Santos

Probst

García-García

et al. 2015

Science of The Total Environment

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The purpose of this study was to assess the influence of anthropogenic factors (infrastructure construction and industrial and wastewater inputs) and hydrological factors (high-magnitude flood events) on metal and organic contamination and on the source variability of sediments taken from the Deba River and its tributaries. The pollution status was evaluated using a sequential extraction procedure (BCR 701), enrichment factor, individual and global contamination factors and a number of statistical analysis methods. Zn, Cu and Cr were found to have significant input from anthropogenic sources, with moderately severe enrichment, together with an extremely high potential risk of contamination. The principal scavenger of Cu and Cr was organic matter, whereas Zn was uniformly distributed among all non-residual fractions. For Fe, the anthropogenic contribution was more obviously detected in bulk sediments (<2 mm) than in fine fractions (<63 μm). Finally, the recent construction of a rail tunnel traversing Wealden Facies evaporites, together with intense rainfalls, was the main reason for the change in the source variability of bottom sediments and metal distribution in headwaters. The occurrence of a high-magnitude flood event resulted in a washout of the river bed and led to a general decrease in fine-grained sediment and metal concentrations in labile fractions of channel-bottom sediments, and a consequent downstream transfer of the pollution.

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“…The relief of the Deba valley is quite abrupt and slope movements are frequent, mostly triggered by intense rainfall [16]. The region is tectonically complex, formed by arched shaped large-scale folds of Latter Jurassic and Early Cretaceous materials that belong to the Basque Arc [17]. Local geology and geomorphology is characterized by weathered cretaceous materials (argilites and siltstones) covered by quaternary colluvial deposits, high topographic relief and the presence of various faults (Figure 1).…”

Section: Geological Contextmentioning

confidence: 99%

Suitability Assessment of X-Band Satellite SAR Data for Geotechnical Monitoring of Site Scale Slow Moving Landslides

et al. 2018

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This work addresses the suitability of using X-band Synthetic Aperture Radar (SAR) data for operational geotechnical monitoring of site scale slow moving landslides, affecting urban areas and infrastructures. The scale of these studies requires high resolution data. We propose a procedure for the practical use of SAR data in geotechnical landslides campaigns, that includes an appropriate dataset selection taking into account the scenario characteristics, a visibility analysis, and considerations when comparing advanced differential SAR interferometry (A-DInSAR) results with other monitoring techniques. We have determined that Sentinel-2 satellite optical images are suited for performing high resolution land cover classifications, which results in the achievement of qualitative visibility maps. We also concluded that A-DInSAR is a very powerful and versatile tool for detailed scale landslide monitoring, although in combination with other instrumentation techniques.

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Geological and isotopic constraints on the structure of the Bilbao anticlinorium (Basque–Cantabrian basin, North Spain)

Cited by 28 publications

References 20 publications

Sedimentary and structural record of the Albian growth of the Bakio salt diapir (the Basque Country, northern Spain)

Sedimentary and structural record of the Albian growth of the Bakio salt diapir (the Basque Country, northern Spain)

Influence of anthropogenic inputs and a high-magnitude flood event on metal contamination pattern in surface bottom sediments from the Deba River urban catchment

Suitability Assessment of X-Band Satellite SAR Data for Geotechnical Monitoring of Site Scale Slow Moving Landslides

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