FURTHER OBSERVATIONS ON THE STONE RUNS OF THE FALKLAND ISLANDS
THE LAST DISCUSSION ON THE STONE RUNS OF THE FALKLAND ISLANDS CRITICISED THE THEORY THAT SOLIFLUCTION WAS A SIGNIFICANT PROCESS IN THEIR EVOLUTION AND IT ADVOCATED THAT THEY EVOLVED IN SITU. THIS PAPER DESCRIBES MORPHOLOGICAL AND INTERNAL
CHARACTERISTICS OF THE STONE RUNS WHICH WERE IGNORED IN PREVIOUS ACCOUNTS, AND CONSIDERS THE SPATIAL RELATIONSHIPS OF THE RUNS WITH GLACIAL LANDFORMS, WITH OTHER SLOPE PHENOMENA AND WITH REMNANTS OF A REGOLITH OF CHEMICALLY ROTTED BEDROCK. IT IS CONCLUDED
THAT PROCESSES SIMILAR TO THOSE WHICH FORM SORTED STONE STRIPES IN PERIGLACIAL ENVIRONMENTS PROBABLY CREATED THE STONE RUNS, BUT THAT THE LATTER EVOLVED ON AN EXCEPTIONAL SCALE ON THE FALKLAND ISLANDS DURING THE PLEISTOCENE BECAUSE OF CLIMATIC, LITHOLOGICAL
Tropical stone lines and podzolized sand plains as paleoclimatic indicators for weathered cratons
Craton ; Cristallin ; Géographie physique ; Géomorphologie climatique ; Indicateur paléoclimatique ; Monde ; Météorisation ; Nappe de gravats ; Paléoclimatologie ; Plaine sableuse podzolisée ; Podzol ; Socle ; Stone line ; Zone intertropicale ; Zone
Consideration of contemporary environments where the genetic processes related to these features can be observed, implies several conditions for prior events in landscape evolution: (1) tropical stone lines may be interpreted as winnowed mudflows
or lag deposits that reflect morphoclimatic events of brief duration (torrential rains) within an arid or semi-arid phase of pronounced global cooling| (2) within the present zone of the prevailing westerlies, stone lines may reflect periglacial activity
during brief interstade fluctuations| (3) in lower latitudes the principal stone line, which commonly truncates saprolites, appears to be late Wisconsinan (Würmian) in age coinciding more or less with the pleniglacial phase| (4) the podzolized sands
1 Stones smaller in size than the spacing between the ice lenses in a frost susceptible matrix are pushed up by basal ice segregation. This nucleation takes place in a dessiccation crack open at the base of the stone (shrinking). 2 Stones bigger
Most erosion rates have neither increased nor decreased significantly in the measurement time. Such a sustained level of erosion gives cause for concern in the context of stone conservation. Causative factors of air quality are discussed and while
SO2 levels have decreased, NO2 and smoke levels show increases. An overall decrease in stone decay in association with the decrease in SO2 levels is thus not in evidence.
The results indicate a relationship between the total erosion loss and the rate of stone pavement areal cover. In addition the paper shows how the technique could be of great assistance in the monitoring of many different types of environmental
and air at the particular sampling sites. Local microclimate and environmental conditions at a particular site are more important in determining the weathering condition of the building stones than the local air studied, a very small contribution
The features include sorted nets, a possible cryoplanation terrace and stone-banked terraces. The remnant periglacial forms owe their existence to a resistant cap of sandstone on the plateau surface which has weathered to form a frost susceptible
hummocks, string bogs, patterned grounds of different types, sand and soil wedges, stone stripes, gelifluction terraces, frost weathering, deflation and dune formation, and phenomena produced by river and lake ice.
These soils of Rana surfaces were studied with reference to vegetation cover and geomorphic position. Their high degree of weathering and the patina of their quartzite stones are comparable to those of soils developed on the oldest rana surfaces