Rock temperatures as an indicator of weathering processes affecting rock art
Archaeology ; Index ; Moisture ; Rock ; South Africa ; Temperature ; Thermal regime ; Weathering
To aid rock art conservation, rock temperatures have been monitored at different depths and acquisition rates in a painted rock shelter in the uKhahlamba-Drakensberg Park (South Africa). Preliminary results, records of winter temperatures
, in the study of rock temperature regimes are presented and briefly discussed with respect to rock weathering mechanisms.
Rock glacier dynamics in a marginal periglacial high mountain environment : flow, movement (1991-2000) and structure of the Argualas rock glacier, the Pyrenees
Creep ; Geophysics ; Mountain ; Periglacial features ; Pyrénées ; Rock glacier ; Sedimentology ; Spain ; Years 1990-99
This paper presents the results of detailed studies on the dynamics of the Argualas rock glacier in the Pyrenees from 1991 to 2000. The aim is to provide a better understanding of the surface movement and dynamics of the tongue-shaped rock glacier
Chemical erosion ; Erosion rate ; Field experiment ; Freeze-thaw cycle ; Island ; Japan ; Volcanic rock ; Weathering
To examine the rate of weathering, field experiments using microweight-loss techniques were carried out. Two kinds of porous rhyolite forming lava domes in Kozushima Island were selected : a younger rock and an older rock. Results show
that the younger rock has a lower weight loss, and the older rock a higher weight loss, and the rates of weight loss for both rocks on the ground surface is larger than that under the saturated grus layer. The first result shows that older rock has a higher rate
of chemical weathering than younger rock. The second result suggests that in addition to chemical weathering, physical weathering such as freeze-thaw weathering occurs on the ground surface.
The effect of rock uplift and rock resistance on river morphology in a subduction zone forearc, Oregon, USA
Relationships between riverbed morphology, concavity, rock type and rock uplift rate are examined to independently unravel the contribution of along-strike variations in lithology and rates of vertical deformation to the topographic relief
is that the rock resistance signal seen in hillslopes is a key control, and more important than rates of rock uplift in some cases, on the river profile and topographic relief.
Development of partial rock veneers by root throw in a subalpine setting
Near Westcliffe, Colorado, data were collected from a transect on the east slope of the Sangre de Cristo Mountains. Ages of pit/mound complexes with rock fragments exposed at the surface by root throw ranged from recent (freshly toppled tree
) to unknown (complete tree decay). Calculations based on dimensions of the pit/mound complexes, estimated time of tree topling, sizes of exposed rock fragments, and percentage rock covers at pit/mound complexes, as well as within the transect area, indicate
that recent rates of root throw have resulted in only partial rock veneering since late Pleistocene deglaciation. Weathering of rock fragments prevents development of an extensive rock veneer.
The AA. report thermal and geo-electrical investigations on 5 rock glaciers located on the Italian side of the Argentera Massif. The aims of the study are to analyse permafrost occurrence and characteristics, and to define the lower elevation limit
for permafrost existence (Lower Permafrost Boundary, LPB) and rock glacier activity. The results are compared to previous studies in mountain areas north of the Argentera, in order to develop a general framework for permafrost existence in the southwestern Alps.
Combination of conventional geophysical methods for sounding the composition of rock glaciers in the Swiss Alps
Alps (The) ; Geophysics ; Glacier ; Mountain ; Permafrost ; Rock glacier ; Soil temperature ; Spatial distribution ; Switzerland
The composition of rock glaciers was sounded by a combination of conventional geophysical methods near the lower limit of mountain permafrost in the Swiss Alps. P-wave velocity, direct current (DC) resistivity and year-round ground surface
temperatures were measured on 32 talus-derived rock glaciers. The combination of these methods provides reliable thermal and structural information on subsurface deposits. In addition, mean annual ground surface temperatures are equally good indicators
Quantitative data on rock surface millimetre-scale roughness are presented concerning the splash and spray geomorphologic domains of 2 coastal profiles developed on Mediterranean carbonate rocks. Differences of the roughness characteristics
are attributed to rock properties, weathering agents and bioerosion. In the splash zone, roughness is related to sparsely distributed pattern of bioerosion, salt weathering and wave attack. In the spray zone, smooth surfaces seem to be the response
to the solution processes that predominate, exerting a more homogenous influence on rock surface evolution.
Aerial and sub-aerial climatic data were collected from a station at 1920 m a.s.l. in the Injisuthi region in the South African Drakensberg. Sensors monitored air temperature, soil surface and rock surface temperature, for 2 rock types : basalt
and sandstone, over the summer and winter of 2001/2002. Rainfall was measured from the summer of 2001 to January 2004. Both rock types maintain relatively high rock temperatures in winter, thus chemical weathering is probably only moisture restricted during
this dry period. Findings highlightthe importance of directly monitoring rock temperature when attempting to discern the rock weathering environment.
Geochemistry and source waters of rock glacier outflow, Colorado Front Range
Colorado ; Geochemistry ; Glacial flow ; Glacier ; Isotope analysis ; Meltwater ; Model ; Mountain ; Rock glacier ; Snow ; United States of America
The AA. characterize the seasonal variation in the geochemical and isotopic content of the outflow of the Green Lake 5 rock glacier (RG5), located in the Green Lakes Valley of the Colorado Front Range. They focus on the 2003 season from
Active layer ; Alaska ; Alps (The) ; Cold area ; Creep ; Geophysics ; Greenland ; Mars planet ; Mountain ; Periglacial features ; Permafrost ; Photogrammetry ; Rock glacier ; Switzerland
This review paper examines thermal conditions (active layer and permafrost), internal composition (rock and ice components), kinematics and rheology of creeping perennially frozen slopes in cold mountain areas. The aim is to assemble current
information about creep in permafrost and rock glaciers from diverse published sources into a single paper that will be useful in studies of the flow and deformation of subsurface ice and their surface manifestations not only on Earth, but also on Mars
Surface temperature differences between minerals in crystalline rocks : implications for granular disaggregation of granites through thermal fatigue
Albedo ; Crystalline rocks ; Granite ; Insolation ; Lithology ; Surface temperature ; Temperature ; Weathering
This work confirms the exixtence of surface temperature differences between minerals in granitic rocks under simulated short-term temperature fluctuations so as to discriminate their potential for initiating granular disaggregation. The influence
of colour, as a surrogate for albedo, and crystal size, as a function of thermal mass are specifically identified because of their ease of quantification. Four rock types with a range of these properties were examined, and subjected to repeated short-term
Structural control and types of movements of rock mass in anisotropic rocks : case studies in the Polish Flysch Carpathians
This article presents the main types of mass movements in the highly anisotropic flysch massifs : lateral spreading and rock flow, topple, translational, rotational and compound sliding and complex type of mass movements, which are illustrated
Recreatief medegebruik bij het festival Rock Werchter
Le mauvais usage récréatif du Festival de Rock de Werchter
Aménagement spatial ; Belgique ; Evénement ; Festival de rock ; Loisir ; Tourisme ; Vlaanderen
Le festival international de rock de Werchter est considéré comme un haut lieu d'activité récréative. L'article analyse la politique des autorités publiques et d'autres acteurs (entre les organisateurs de l'événement) concernant l'événement à
On the origin of rock fragment mulches on vertisols : a case study from the Ethiopian highlands
This paper presents the case of a natural rock fragment (RF) mulch whose lithology indicates that the RF are up-squeezed by the local vertisol. Based on the data from the experimental site located in the pass of Enda Maryam, Tigray, Northern
identical conditions show that the shape of the pillars is mainly the consequence of the distribution and density of fissures in the rock, its stratification, and different rock strata composition. The rock forms on the pillars are divided into subcutaneous
forms, composed rock forms, and forms shaped by rain water. Because of the exceptional characteristics of this karst phenomenon in China, we propose that the term shilin be used for this type of stone forest in the profesional literature. - (IKR)