Physical deterioration of sedimentary rocks subjected to experimental freeze-thaw weathering
This paper addresses the influence of pre-existing flaws on the durability of ten sedimentary rocks under experimental freeze-thaw weathering. Results suggest that the presence or absence of rock flaws alone does not control deterioration mode
Investigations into the relationship between changes in internal moisture regimes and rock surface deterioration in cavernous sandstone features
In this study the role of internal moisture movement is tested through monitoring moisture and surface deterioration dynamics in April 2008 and April 2009 within 2 large cavernous features (mega-tafoni) in the Golden Gate Highlands National Park
, South Africa (GGHNP). Data are presented from surveys of internal moisture (using electrical resistivity tomography, ERT), surface moisture (using a Protimeter) and deterioration (using surface hardness as recorded with an Equotip as a proxy for surface
deterioration) across 5 transects. In addition a high resolution temperature record is presented to assess the influence of micro-climates within the caverns. The presence of well-established biofilms suggests an even more complex interaction between moisture
, surface development and biological activity. A model is presented therefore which integrates this paradox by proposing a non-linear relationship between moisture dynamics, facilitation of biofilm formation, and deterioration within cavernous features.
Subsistence and survival in the Sahel. Responses of households and entreprises to deteriorating conditions and development policy in the Mopti Region of Mali
relations. It focusses on the adjustments made by rural and urban households and enterprises in their subsistence activities and production as a response to deteriorating circumstances (the economic stagnation). - (AGD)
The purpose of the present study is to measure and map weathering rates for a single tombstone type (century-old Vermont marble slabs), and to use spatial correlation to indicate the relative importance of various marble deterioration processes
. The results at 320 cemeteries throughout North America and Hawaii demonstrate that air pollution (probably SO2) has been responsible for more deterioration of carbonate building stone and statuary than have other weathering processes.
up to 19,000 years B.P., when a phase of climatic deterioration began, leading to a period of hyperaridity which dominated from 16,300 to 13,000 yr B.P. The early Holocene pluvial occurred from 12,500 to 6 500 yr B.P. and was followed by renewed
climatic deterioration and the current phase of hyperaridity.
Discussion of recent attempts in Cuba to become a tourist mecca in the context of a deteriorating economic situation. In 1989, Canada was the leading source of tourists visiting Cuba. - (DWG)
Durban municipality only provided housing for its Black population after conditions in informal housing on the city periphery deteriorated in the 1920s. The problems of formulating a housing policy and the creation of Lamontville are examined
Deterioration of grazing and bush encroachment in commercial farming areas, and denudation through grazing and wood use in subsistence areas are described and assessed. - (AJC)
There is great regional variation in the intensity of response of vegetation to Lateglacial climatic events in Europe. Between 11,000 and 10,000 radiocarbon years BP, a severe climatic deterioration brought about major changes in the species
there was little or no change in vegetation at many sites, although there was inflow of inorganic materials into some lake basins. There is weaker evidence for a climatic deterioration which caused upland erosion between 12,000 and 11,800 BP. This can be seen
in evidence from Ireland and Britain but it is weakly expressed and in evidence from only some sites in Denmark and northern Germany. There is no evidence for such a deterioration in the Alps. Very tentative climatic curves are presented to draw attention
to regional differences which have not been sufficiently appreciated in the literature. The deterioration from 11,000 to 10,000 BP is correlated with a readvance of polar water into the eastern North Atlantic. Evidently it affected coastal areas strongly
LA CROISSANCE DE LA POPULATION URBAINE EST UNE CONSEQUENCE DE L'ATTRACTIVITE D'UNE VILLE. UNE CROISSANCE RAPIDE DE POPULATION PEUT DETERIORER ET SOUVENT DETERIORE CETTE ATTRACTIVITE ET REDUIT AINSI LA RAPIDITE DE LA CROISSANCE. L'A. DEVELOPPE UN
dated at more than 8000 cal yr B.P. The AA. also ask the questions: to what degree does the wood of this species deteriorate over time and does this deterioration represent a barrier to the development of exceptionally long dendrochronological data bases?