Landscape dissection, isostatic uplift, and the morphologic development of orogens

Gilchrist, A. R.; Summerfield, Michael A.; Cockburn, H. A. P.

doi:10.1130/0091-7613(1994)022<0963:ldiuat>2.3.co;2

Cited by 95 publications

(59 citation statements)

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“…Since England (1981) and Guillaume and Guillaume (1982), different authors have claimed that the enhanced Plio-Quaternary erosion induced rock uplift in the Central and Western Alps via positive feedback mechanisms (Gilchrist et al, 1994;Schlunegger and Hinderer, 2001;Cederbom et al, 2004;Champagnac et al, 2007;Champagnac et al, 2008;van der Beek and Bourbon, 2008). In case where erosional unloading drives rock uplift through isostatic adjustment, the ratio between erosion and associated isostatic rebound is controlled by the density contrasts between the crust (ρ~2.8g/cm 3 ) and the mantle (ρ~3.25 g/cm 3 ).…”

Section: Erosional Unloadingmentioning

confidence: 99%

“…1A) have served as a classical example to explore the geodynamic development of the coupled orogen/foreland basin system (e.g. Pfiffner, 1986;Schmid et al, 1996;Schlunegger et al, 2007), and to search for effects of possible feedback mechanisms between crustal accretion and surface erosion (Gilchrist et al, 1994;Schlunegger & Willett, 1999;Willett et al, 2006;Bonnet et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

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Erosion-driven uplift of the modern Central Alps

et al. 2009

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We present a compilation of data of modern tectono-geomorphic processes in the Central European Alps which suggest that observed rock uplift is a response to climate-driven denudation. This interpretation is predominantly based on the recent quantification of basinaveraged Late Holocene denudation rates that are so similar to the pattern and rates of rock uplift rates as determined by geodetic leveling. Furthermore, a GPS data-based synthesis of Adriatic microplate kinematics suggests that the Central Alps are currently not in a state of active convergence. Finally, we illustrate that the Central Alps have acted as a closed system for Holocene redistribution of sediment in which the peri-Alpine lakes have operated as a sink for the erosional products of the inner Central Alps.While various hypotheses have been put forward to explain Central Alpine rock uplift (e.g. lithospheric forcing by convergence, mantle processes, or ice melting) we show with an elastic model of lithospheric deformation, that the correlation between erosion and rock uplift rates reflects a positive feedback between denudation and the associated isostatic response to unloading. Thus, erosion does not passively respond to advection of crustal material as might be the case in actively converging orogens. Rather, we suggest that the geomorphic response of the Alpine topography to glacial and fluvial erosion and the resulting disequilibrium for modern channelized and associated hillslope processes explains much of the pattern of modern denudation and hence rock uplift. Therefore, in a non-convergent orogen such as the Central European Alps, the observed vertical rock uplift is primarily a consequence of passive unloading due to erosion.

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Section: Erosional Unloadingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Erosion-driven uplift of the modern Central Alps

et al. 2009

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“…Where denudation rates across an area vary according to lithology so the isostatic uplift will be a function of the average denudation rate (e.g. Farrant et al, 1995), although even the maximum isostatic compensation will be only about five-sixths (0·82) of the denudation due to the lower densities of surface rocks compared with those deeper in the crust (Gilchrist et al, 1994). If the more rapidly denuding lithology constitutes a major outcrop component of the area then isostatic unloading across its outcrop area will lead to relative uplift of more slowly denuding outcrops.…”

Section: Denudation and Isostasymentioning

confidence: 99%

Tortoises and hares: dissolution, erosion and isostasy in landscape evolution

Simms

2004

Earth Surf Processes Landf

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Denudation mechanisms differ fundamentally between limestone and silicate rock types, which are subject to very different rate thresholds and enhancers/inhibitors. Silicates are removed largely by erosion, the mechanical entrainment and transport of particles. This is a relatively high energy, and highly episodic, process which occurs only when a minimum threshold flow velocity is exceeded; it is inhibited by vegetation cover and favoured by strongly seasonal runoff. Limestone is removed largely by chemical dissolution at a rate directly proportional to runoff. Dissolution is a relatively low energy process that can occur at any flow velocity or in static water; in general it is enhanced by vegetation cover and non-seasonality of runoff. These contrasting factors in the denudation of silicates versus limestone can produce strikingly uneven rates of surface lowering across a landscape, sometimes akin to the well known 'tortoise and hare race', where the slow and steady denudation of limestones may in the long term exceed the sometimes rapid, but often localized and episodic, erosion of silicates. Prolonged exposure of limestone to a humid temperate climate in a tectonically stable environment produces lowrelief corrosion plains in which limestone uplands are anomalous and, in most instances, due to recent unroofing from beneath a siliciclastic cover. In a highly seasonal or semi-arid climate almost the exact inverse may develop, with 'flashy' runoff and sparse vegetation favouring erosion rather than dissolution. Even under a constant humid climate progressive unroofing of a thick limestone unit within folded siliciclastics may lead to a topographic inversion over time, with the limestone outcrop always forming a topographic low flanked by siliciclastic uplands. Valleys will be initiated on anticlinal crests, where the limestone is first unroofed, but progressive lowering of the limestone causes these valleys to migrate to their final position in the synclinal troughs. In humid climates isostatic compensation in response to slow, but continuous, denudation of extensive limestone outcrops may be a significant factor in the development of relief on adjacent, more slowly eroding, silicate outcrops.

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“…La isostasia debida a la erosión de los sistemas montañosos (Gilchrist et al, 1994;Montgomery 1994) parece ser un argumento más a favor del modelo propuesto por Hack (1973Hack ( , 1975, ya que es posible una larga estadía de las formas del relieve como se ha evaluado mediante simulaciones (e. g., Baldwin y Whipple, 2003).…”

Section: Los Knickpoints En El Sistema Fluvialunclassified

Estado actual del conocimiento, clasificación y propuesta de inclusión del término knickpoint en el léxico geológico- geomorfológico del español

Castillo¹,

Lugo-Hubp²

2011

BSGM

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ResumenEl término knickpoint se utiliza comúnmente en geomorfología, principalmente en lengua inglesa, para denominar aquellas rupturas bruscas de la pendiente del lecho de un río a lo largo de su perfil longitudinal. Los knickpoints son expresión del desequilibrio de un sistema fluvial y pueden estar presentes tanto en ríos aluviales como en ríos en lecho rocoso. Los avances en geomorfología fluvial y evolución del paisaje indican que los knickpoints resultan de distintos procesos tectónicos, climáticos y geomorfológicos. No obstante, no existe hasta ahora una definición formal del término. El uso actual del concepto de knickpoint no proporciona información alguna sobre los mecanismos de su formación y por lo tanto, se refiere a la morfología del lecho fluvial. La acotación del término en español es necesaria, ya que éste ha sido utilizado, pero no ha sido definido de manera formal. En el presente estudio se hace una revisión del término y se realiza una clasificación de los knickpoints con base en un criterio genético, del cual se reconocen cinco tipos: glacial, litológico, tectónico, eustático y glacio-isostático (o glacioeustático). Se propone aquí la inclusión del término en el léxico geológico y geomorfológico del español, agregando un adjetivo calificativo que defina el origen.Palabras clave: knickpoint (punto de inflexión), desequilibrio, perfil longitudinal, sistema fluvial, ríos en lecho rocoso. Abstract The term knickpoint is commonly used in geomorphology to distinguish any abrupt change in the channel

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Landscape dissection, isostatic uplift, and the morphologic development of orogens

Cited by 95 publications

References 0 publications

Erosion-driven uplift of the modern Central Alps

Erosion-driven uplift of the modern Central Alps

Tortoises and hares: dissolution, erosion and isostasy in landscape evolution

Estado actual del conocimiento, clasificación y propuesta de inclusión del término knickpoint en el léxico geológico- geomorfológico del español

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