Frost bursting : a violent expression of frost action in rock
The purpose of this paper is to substantiate an explosive origin for some rock breakdown by identifying the pertinent environmental conditions and mechanical properties of the rock in which it occurs.
Incipient motion conditions for single rock fragments in simulated rill flow
This paper examines incipient motion conditions for single rock fragments in simulated rill channels : threshold conditions for rock fragments in rill flow will be compared with existing theory (Shields) for channels and rivers.
Discharge and sediment-load characteristics of the Hilda rock-glacier stream, Canadian Rocky Mountains, Alberta
Water discharge and sediment load characteristics of the Hilda rock-glacier stream are described for portions of the 1985 and 1986 ablation seasons. The hydrological behavior of the Hilda rock-glacier stream suggests that the rock glacier acts
as a buffering factor in basin runoff as compared with a similar glacierized basin. In addition, the rock glacier acts conservatively in sediment release from the basin and promotes denudation by dissolution and material transport as dissolved load.
The distribution of permafrost in rock glaciers of the southern Alps (France)
Results of electrical resistivity surveys performed on ten rock glaciers in the southern Alps, in the summer of 1986. The conclusion that these rock glaciers are essentially inherited forms, testifying the passage of recent cold periods
, is confirmed by the discovery on three sites of rock glaciers with a heterogeneous structure, a thawed central part and an accumulation of ice at the snout. It suggests that the rock glaciers in the southern Alps were formed, for the most part, during
Beach-rocks of coastal beaches or of sand reef cays could be considered as witnesses: 1) of the coastal morphology, of the sedimentary conditions and of the altitudinal sea level| 2) of the wave-exposure. It's in this view that are analysed: 1
) the fossilized organisms into the beach-rocks| 2) the organisms that could be fossilized or apt to leave a matrix or a print, that colonize beach-rocks when they are exposed and when they form hard-substrates.
Réflexion sur les beach-rocks de la mer Méditerranée in Le beach-rock.
Ancien rivage ; Beach rock ; Diagenèse ; Géographie physique ; Géomorphogenèse ; Géomorphologie littorale ; Holocène ; Liban ; Littoral ; Méditerranée ; Méditerranéens, pays ; Niveau marin ; PICG 200 ; Quaternaire marin ; Soudan ; Stratigraphie
Numerous examples all along the Mediterranean coastline show that beach-rock frequently originates inside soft fossil holocene marine deposits and is exposed only when the coast recedes. The present beach often hides it during the summer, thus
making it possible for a veil of sand to cement itself unconformably on the slabs of beach-rock. The phenomenon of receding coastlines being general in the Mediterranean, it is quite natural that beach-rock forms in this ancient sedimentary stock
Essai de synthèse sur le beach-rock in Le beach-rock.
Beach rock ; Géographie physique ; Géomorphogenèse ; Littoral ; Milieu marin ; Niveau marin ; PICG 200 ; Sédimentologie
A l'issue du colloque sur le beach-rock, les participants ont élaboré la définition suivante: le beach-rock est une formation sédimentaire indurée sous l'effet d'une cimentation carbonatée, réalisée au niveau de l'étage médiolittoral. Il existe des
beach-rocks fossiles, situés à des altitudes supérieures ou au contraire inférieures au niveau actuel de la mer.
Cation-ratio dating of rock varnish : a geographic assessment
This paper presents the results of a three-year study of the potential and limitations of CR dating. The unique role of rock varnish as compared to other surface exposure dating methods is its ability to determine the timing of last abrasion
Les rock doughnuts (littéralement pets de nonnes rocheux) sont les rebords en surplomb de cavités de météorisation (gnammas) creusées dans des roches cristallines. Exemples pris dans les Waddikee Rocks gneissiques, dans le Nord de la Péninsule
The Schmidt hammer, weathering and rock surface roughness
Here, careful measurement of the influence of weathering on rock surface texture is used to elucidate the relationships between weathering, roughness and Schmidt hammer rebound values.
Developments in a non-destructive method of determining rock strength
The results presented here confirm the use of the ultrasonic apparatus as a technique for indirectly determining rock strength by determining Dynamic Young's Modulus. The results also indicate that the ultrasonic apparatus can be used as a field
Beach rock litorale Morphodynamik und Meeresspiegeländerungen nach Befunden auf Euboa (Griechenland). in Beiträge zur Geomorphologie und Länderkunde. Prof. Dr. Harmut Valentin zum Gedächtnis.. (Beach rock. Littoral morphodynamics and sea level
Beach rocks are beach materials lithified above high tide level. The beach material will be cemented under the prevailing conditions of Mediterranean climate there. Before being cemented beach materials must have been wetted, and this process
is linked to rare oceanographic-climatic conditions, such as wind-tides lifting up the sea level and extending the swash zone landward. Under even these conditions beach rocks are destroyed by backswash and breakers, too. Formation and destruction of beach
rock occur at the same time. Periods of months, years or 10 years are required for beach rock formation, whereas beach rocks may be destroyed in periods of 10-10 years. The authors working on beach rock up to now agree beach rock to be an excellent
Characteristics and origin of rock varnish from the hyperarid coastal deserts of northern Peru
This paper describes a new variety of rock varnish from the hyperarid coastal deserts of Peru, presents experimental evidence for a physicochemical mechanism that enhances Mn relative to Fe, and takes a closer look at the controls on the Mn : Fe
ratios in rock varnish. This work is particularly relevant to paleoenvironmental interpretations of the variations in Mn : Fe ratios in rock varnishes.
The form of rock slopes in tropical limestone and their associations with rock mass strength
à l'intérieur de ce continuum, mise en évidence de l'importance des propriétés de rock mass spécifique en déterminant des variations spatiales de forme de versant.
The clay mineralogy and age of deeply weathered rock in north-east Scotland in Weathered mantles (saprolites) over basement rocks of High Latitudes = Les manteaux d'altération sur les socles des Hautes Latitudes.
This paper is concerned with the clay mineralogy of the saprolites and its bearing on the problem of dating the period or periods under which the weathering took place. Data for 29 sites on the clay mineralogy of saprolites in different rock types