Estimation of growth rates of coastal tafoni in tuff at Oku-Matsushima
Erosion chimique ; Honshū ; Japon ; Littoral ; Météorisation ; Sel ; Taffoni ; Tuf ; Vitesse d'érosion
Chemical erosion ; Coastal environment ; Erosion rate ; Honshu ; Japan ; Salt ; Taffoni ; Tufa ; Weathering
This paper tries to estimate the rate of tafoni growth and duration of tafoni development using the Matsukura and Matsuoka's (1996) equation representing relationships between rates of tafoni growth and rock properties in Oku-Matsushima Coast.
Effect of rock hardness and moisture content on tafoni weathering in the granite of Mount Doeg-Sung, Korea
Corée du Sud ; Granite ; Humidité ; Météorisation ; Sel ; Taffoni
Granite ; Moisture ; Salt ; South Korea ; Taffoni ; Weathering
Relationships are investigated between growth processes of granite tafoni and rock properties such as rock hardness and moisture content. Field evidence shows that the rock surface of the inner backwalls and ceiling of tafoni have reduced hardness
and higher moisture content compared to the outer visor of tafoni and to vertical cliff walls with no tafoni. This suggests that tafoni arise in weathered rock where conditions of low strength and high moisture content are both satisfied.
Arid area ; Arizona ; Carbonate ; Chemical erosion ; Inselberg ; Microstructure ; Taffoni ; United States of America ; Weathering
Papago Park is a pediment-inselberg complex that hosts a variety of well developed tafoni and alveolar weathering forms. The aim of this paper is to analyse the nature of chemical weathering associated with the tafoni using backscatter electron
Carbonate ; Evaporite ; Geomorphometry ; Salt ; Taffoni ; Tufa ; United States of America ; Utah ; Weathering
This paper concerns a type of cavernous weathering that is well developed on the flanks of Crystal Peak. The recesses, with their visors and large cavities, have the character of typical tafoni. Tafoni at Crystal Peak are remarkable because
Many tafoni occur on the faces of marine cliffs on three uplifted shore platforms with different altitudes and with known ages of emergence. The AA. estimate the mean value of the ten largest depths of tafoni, the period of their formation
Rapid honeycomb weathering (tafoni formation) in greywacke, S. E. Australia
Australie ; Grauwacke ; Géographie physique ; Littoral ; Météorisation ; Nid d'abeille ; Taffoni ; Victoria
Le développement de tafonis en nids d'abeille sur les murs de grauwackes continentaux du Crétacé inférieur exposés aux embruns et construits en 1943 et 1949 montre que ce type de tafonis peut être un facteur important du recul des côtes rocheuses.
Arid area ; Arizona ; Dating ; Erosion rate ; Geochronology ; Pleistocene ; Taffoni ; United States of America ; Weathering
Tafoni are pits formed by non-uniform weathering in otherwise uniform rock. Two equations have been proposed for the rate of development of tafoni, both based on 2000-year-old outcrops from the coast of Japan. The AA. have taken tafoni measurements
from the Meteor Crater, Arizona, and vicinity that extend the equations back at least 50 000 years. The main interest in this study is to see how the rate of tafoni development changes with time, and to determine the mathematical form of the equation
which best describes the rate. The AA. also intend to assess the possibility of using tafoni development as a dating techniques for Pleistocene surfaces.
Chemical erosion ; Climatic cycle ; Evaporation ; Model ; Porosity ; Salt ; Taffoni ; Weathering
Throughout the world, large caves in rocks (tafoni) are found, which originate from salt weathering. The growth of tafoni has been studied with a model that describes how a rock surface, containing a small pit, disintegrates by salt crystallization
Après un rappel des processus de formation des taffonis, l'A. décrit des taffonis bien développés à l'île d'Elbe où ils sont très actifs et au montPisani (Pise) où ils sont pour la plupart inactifs. L'A. explique l'activité des taffonis par la
Andalusia ; Arid area ; Eolian deflation ; Flysch ; Lichen ; Lithology ; Mediterranean area ; Micromorphology ; Precipitation ; Salt ; Spain ; Taffoni ; Water erosion ; Weathering
Using a combination of field, laboratory and micromorphological evidence, this study examines tafoni in the El Chorro area of Andalucia, and makes inference concerning the processes responsible for their formation. 25 tafoni were randomly selected
for field examination. A phased model of tafone evolution is proposed whereby the features pass through 4 phases of development-initiation, enlargement, amalgamation and degradation; in the study area there are examples of tafoni in each of these phases
. Much of the evidence suggests that the tafoni are actively developing under current environmental conditions.
Description des taffonis et formes de météorisation semblables holocènes de l'Ecosse à la Grèce dans des grès, éolianites ou laves. Leur orientation générale vers la mer suggère une action de l'eau salée des embruns.
Etude des relations entre la vitesse d'agrandissement des taffonis et les propriétés de la roche, dans 24 sites du Japon, où des taffonis se développent au front des falaises marines et sur les plateformes littorales soulevées. L'hypothèse de
l'haloclastisme implique que la vitesse de croissance des taffonis dépende des propriétés de la roche: taille des pores et résistance des matériaux. Des mesures en laboratoire ont donc été effectuées sur des échantillons sains prélevés sur les plateformes
, and therefore their attribution is re-evaluated on the basis of geomorphological analysis and tafoni genesis theories. In fact, these cavities are tafoni developed in bornhardts, castle koppjes, tors and corestones.
Tafoni development in a cryotic environment : an example from Northern Victoria Land, Antarctica
Antarctique ; Granite ; Météorisation ; Régime thermique ; Région polaire ; Sel ; Taffoni ; Victoria Land ; Vitesse du vent ; Zone froide
Antarctica ; Cold area ; Granite ; Polar region ; Salt ; Taffoni ; Thermal regime ; Weathering ; Wind speed
This paper does not discuss the origin of tafoni but rather attempts to contribute to understanding the processes involved in their growth. In particular, the paper aims to analyse the role of the thermal regime and of the wind in the development
of these features. Geomorphological characterization of more than 60 tafoni in three different Antarctic sites (two coastal and one inland) between 74 and 76°S with sampling of weathering products and salt occurrences are described together with thermal data
(on different surfaces) and wind speed recorded in different periods of the year in a selected tafone close to the Italian Antarctic station. The data suggest that there is no single key factor that drives the tafoni development, although thermal stress seems
The role of rock surface hardness and internal moisture in tafoni development in sandstone
Afrique du Sud ; Drakensberg ; Grotte ; Grès ; Humidité ; Modèle conceptuel ; Météorisation ; Piedmont ; Taffoni ; Tomographie de résistivité électrique
Cave ; Conceptual model ; Electrical resistivity tomography ; Moisture ; Piedmont ; Sandstone ; South Africa ; Taffoni ; Weathering
Granizo ; Gruta ; Humedad ; Meteorización ; Modelo conceptual ; Piemonte ; Taffoni ; África del Sur
In this study, Electric Resistivity Tomography (ERT) has been used to map moisture distribution within inner walls of tafoni developed in sandstone, and an Equotip device used to measure rock surface hardness as a proxy measure of the degree
of weathering and case hardening. Seven large tafoni in the Golden Gate Highlands National Park (South Africa), varying in size and degree of development have been monitored. A dynamic relationship between surface hardness, degree of weathering and internal
Domaine aride ; Facteur lithologique ; Géographie physique ; Géomorphodynamique ; Géomorphogenèse ; Haloclastie ; Kenya ; Lake Magadi region ; Limon ; Microrelief ; Tafoni ; Trachyte
Tafoni and honeycomb weathering are described from indurated lacustrine silts and trachyte lavas respectively. Although salt weathering is responsible for the landform observed, it is acknowledged that they are convergent forms and can develop
through a variety of weathering mechanisms. The key to tafoni development appears to be their morphology, which creates a micro-environment in which weathering is enhanced.
Australia ; Conglomerate ; Drainage ; Escarpment ; Fault ; Folding ; Geomorphogenesis ; Mesozoic ; Mountain ; South Australia ; Speleothem ; Structural geomorphology ; Taffoni
to tafoni, the development of split cobbles and the significance of Baxter Hills in unravelling the denudation chronology of the region in which it is located.