Geomorphology and geochronology of sackung features (uphill-facing scarps) in the Central Spanish Pyrenees

Gutiérrez-Santolalla, F.; Acosta, Enrique; Ríos, Santiago; Guerrero, Jesús; Lucha, Pedro

doi:10.1016/j.geomorph.2005.01.012

Cited by 88 publications

(56 citation statements)

References 34 publications

(100 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Only in few locations, mainly in less densely foliated gneisses, block toppling is observed. The uneven topography of the valley flanks and the scarps with pronounced along-strike variations in their height resemble the morphologic expressions caused by large-scale sagging processes and the accompanying smaller-scale gravitational processes (Agliardi et al 2001;Dramis & Sorriso-Valvo 1994;Gutiérrez-Santolalla et al 2005 and references therein; Hippolyte et al 2006;Madritsch & Millen 2007). At least some of the scarp-related faults are still active: At the Oberalp Pass, geodetic measurements along a ~170-m-long profile reveal height changes of ~0.7 mm/yr across a fault with an uphill-facing scarp (Eckhardt et al 1983).…”

Section: Geological Setting and Field Observationsmentioning

confidence: 91%

“…Postglacial differential uplift might have contributed to the formation of uphill-facing scarps also in other regions, for example, the Rocky Mountains, the Pyrenees, Scotland or the Argentera Mercantour Massif in southeastern France (Radbruch-Hall 1978;Flageollet 1989;Gutiérrez-Santolalla et al 2005;Jarman 2006;Jomard 2006). Similar to the Swiss Alps, the scarps in these regions occur on the flanks of formerly glaciated valleys and strike parallel to the valley axes.…”

Section: B)mentioning

confidence: 99%

“…They typically occur along the flanks of valleys and form by uplift of the valley-side block relative to the mountain-side block. Uphill-facing scarps have been reported from many mountain ranges, e.g., the Rocky Mountains (McCalpin & Irvine 1995), the Coast Mountains of British Columbia (Bovis 1982), Alaska (Radbruch-Hall 1978), the Northern Carpathian Mountains (Mahr & Nemcok 1977), the Pyrenees (Gutiérrez-Santolalla et al 2005) and in Scotland (Jarmann 2006). They were earlier described in the European Alps (Jäckli 1951(Jäckli , 1965 and extensively studied by numerous workers (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Renner 1982;Eckardt et al 1983;Agliardi et al 2001;Persaud & Pfiffner 2004;Amann 2005;Hippolyte et al 2006;Jomard 2006). The formation of the scarps has been attributed to different mechanisms, which can be summarized as gravitational slope deformation (Hippolyte et al 2006;Gutiérrez-Santolalla et al 2005), neotectonic fault-ing (Eckhardt et al 1983;Persaud & Pfiffner 2004) or differential postglacial uplift (Jäckli 1965;Jarman 2006). Which of the proposed mechanisms is definitely responsible for scarp formation is still not fully resolved.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Composite faults in the Swiss Alps formed by the interplay of tectonics, gravitation and postglacial rebound: an integrated field and modelling study

2008

View full text Add to dashboard Cite

Along the flanks of several valleys in the Swiss Alps, well-preserved fault scarps occur between 1900 and 2400 m altitude, which reveal uplift of the valley-side block relative to the mountain-side block. The height of these uphillfacing scarps varies between 0.5 m and more than 10 m along strike of the fault traces, which usually trend parallel to the valley axes. The formation of the scarps is generally attributed either to tectonic movements or gravitational slope instabilities. Here we combine field data and numerical experiments to show that the scarps may be of composite origin, i.e. that tectonic and gravitational processes as well as postglacial differential uplift may have contributed to their formation. Tectonic displacement may occur as the fault scarps run parallel to older tectonic faults. The tectonic component seems, however, to be minor as the studied valleys lack seismic activity. A large gravitational component, which is feasible owing to the steep dip of the schistosity and lithologic boundaries in the studied valleys, is indicated by the uneven morphology of the scarps, which is typical of slope movements. Postglacial differential uplift of the valley floor with respect to the summits provides a third feasible mechanism for scarp formation, as the scarps are postglacial in age and occur on the flanks of valleys that were filled with ice during the last glacial maximum. Finite-element experiments show that postglacial unloading and rebound can initiate slip on steeply dipping pre-existing weak zones and explain part of the observed scarp height. From our field and modelling results we conclude that the formation of uphill-facing scarps is primarily promoted by a steeply dipping schistosity striking parallel to the valley axes and, in addition, by mechanically weaker rocks in the valley with respect to the summits. Our findings imply that the identification of surface expressions related to active faults can be hindered by similar morphologic structures of non-tectonic origin.

show abstract

Section: Geological Setting and Field Observationsmentioning

confidence: 91%

Section: B)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Composite faults in the Swiss Alps formed by the interplay of tectonics, gravitation and postglacial rebound: an integrated field and modelling study

2008

View full text Add to dashboard Cite

show abstract

“…Spreading of fractures due to tensional stresses and brittle failure during block sliding and subsequent erosion of the uphill side can cause counterscarps even in the case of a shallow-dipping sliding plane (Gutiérrez-Santolalla et al, 2005;Li et al, 2010). Moreover, at the transition where the dip of the sliding surface becomes steeper, higher tensional stresses increase brittle failure and rock fragmentation along pre-existing structures, similar to the proposal by Li et al (2010) for bending moment faults caused by folding at the hinge of an anticline.…”

Section: Kinematic Modelmentioning

confidence: 68%

Gravitational reactivation of a pre-existing post-Caledonian fault system: the deep-seated gravitational slope deformation at Middagstinden, western Norway

Schleier¹,

Hermanns²,

Krieger³

et al. 2016

NJG

View full text Add to dashboard Cite

The origin of linear features in mountain terrain that form distinct vertical steps is generally not obvious and has been discussed to be related to either tectonic faulting or gravitational slope deformation. A strong geomorphological lineament running oblique to the slope and forming a convex step in the topography is located on the mountain Middagstinden just west of the valley Innfjorddalen, western Norway. In previous studies this lineament has been interpreted to be the surface expression of a Holocene reverse fault previously called the Berill Fault, indicating the first evidence for neotectonic faulting in southern Norway. Now, detailed structural field mapping has revealed the existence of a set of normal fault planes striking subparallel to this lineament and to the main extensional faults associated with the Caledonian collapse. Electric resistivity tomography (ERT) profiles of the valley floor and excavated parallel trenches confirm the regional extent of the fault, but the sediments observed in the trenches do not indicate any Holocene activity. Furthermore, the lineament is a limiting structure of a large rock-slope instability. Kinematic feasibility tests based on structural field measurements indicate wedge failure along the intersection of the fault and the local foliation. However, this intersection line is not exposed on the slope surface. Hence, simple wedge or translational sliding along the slope is not feasible, except in its uppermost part. Both the displacements observed by differential global navigation satellite system (dGNSS) surveys and the geomorphological characteristics, for instance, counterscarps, superficial mass movements, coherent slide blocks and slope bulging, indicate complex deformation mechanisms. The deformation evidently changed along the slope in type and degree including planar sliding in the uppermost part, potentially large wedge sliding in the middle part, and incremental internal deformation in a direction out of the slope in the lower part. The complex kinematics and geomorphological characteristics account for the definition of a deep-seated gravitational slope deformation (DSGSD). Furthermore, the findings reveal that the geomorphological lineament is of gravitational origin and not neotectonic. It has formed by a reactivation of the pre-existing, Caledonian, normal fault system due to the DSGSD, and is hence an example of pseudotectonics ('apparent reverse fault').

show abstract

Long-term dynamics of rockslides and damage propagation inferred from mechanical modeling

Lacroix

Amitrano

2013

J. Geophys. Res. Earth Surf.

View full text Add to dashboard Cite

[1] Long-term observations of large active rockslides show accelerating deformation over many thousands of years since the last deglaciation. The effect of deglaciation on slope stability is however poorly understood due to (1) limited long-term observations and (2) a complex interaction between glacier retreat and hydrogeological, mechanical, and morphological processes. To assess the sensitivity of rockslide dynamics to these different processes, a model of progressive damage through intact rock mass is developed in this study, based on the finite element method. This model uses time-to-failure laws based on rock laboratory creep experiments. It is able to reproduce progressive damage localization along shear bands associated with strain rate acceleration as observed during tertiary creep. The model reproduces the different phases of deformation associated with morphologies typical of large rockslides. This model is thus suitable for simulating the dynamics of large rockslides and the transition from initiation to rapid sliding. The sensitivity of rockslide kinematics and morphology to different mechanical properties is analyzed. This analysis shows that the time evolution of the rockslide can be inferred with the knowledge of only one time parameter, independent of the knowledge of the mechanical properties of the rock mass. This parameter is here chosen as the time when the summit slope displacement has reached 10 m, a parameter that can be estimated with cosmogenic dating. The model is then used to study the effects of deglaciation on the valley flank stability and the formation of large rockslides. This study shows that the deglaciation velocity can affect the morphology of the rockslide, with the shear band of the rockslide emerging at higher elevation as the velocity decreases. We also show that the response to the deglaciation can last several thousands of years after the glacier retreat.Citation: Lacroix, P., and D. Amitrano (2013), Long-term dynamics of rockslides and damage propagation inferred from mechanical modeling,

show abstract

Geomorphology and geochronology of sackung features (uphill-facing scarps) in the Central Spanish Pyrenees

Cited by 88 publications

References 34 publications

Composite faults in the Swiss Alps formed by the interplay of tectonics, gravitation and postglacial rebound: an integrated field and modelling study

Composite faults in the Swiss Alps formed by the interplay of tectonics, gravitation and postglacial rebound: an integrated field and modelling study

Gravitational reactivation of a pre-existing post-Caledonian fault system: the deep-seated gravitational slope deformation at Middagstinden, western Norway

Long-term dynamics of rockslides and damage propagation inferred from mechanical modeling

Contact Info

Product

Resources

About