References of "Ek, Camille"
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See detailKarst in granitic rocks, South Cameroon: cave genesis and silica and taranakite speleothems
Willems, Luc ULg; Compère, Philippe ULg; Hatert, Frédéric ULg et al

in Terra Nova (2002), 14(5), 355-362

A cave in granitic rocks was studied in Mezesse, South Cameroon. Coralloid speleothems, draperies and dissolution traces on the cave walls attest to its truly karstic nature. The speleothems consist of ... [more ▼]

A cave in granitic rocks was studied in Mezesse, South Cameroon. Coralloid speleothems, draperies and dissolution traces on the cave walls attest to its truly karstic nature. The speleothems consist of microlayers of opal and taranakite (K,NH4)Al-3(PO4)(3)(OH).9H(2)O. They indicate a significant mobilization of silica, Al and K from granite during the formation of the cave. Identification of silicified bacteria in the speleothems layers suggests a possible role of these micro-organisms in silica deposition. The presence of taranakite and of silicified organic remains within the speleothems lead to a better understanding of the genesis of the cave. [less ▲]

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See detailLe Traçage : un outil pour l'établissement des zones de surveillance des captages en terrain karstique. Le cas de Hastière (Province de Namur, Belgique)
Michel, Goerges; Meus, Philippe ULg; Thys, Georges et al

in Bulletin de la Société Géographique de Liège (1999), 37

In response to the request of the Groundwater Service of the Walloon Region, the Commission Wallonne d'Etude et de Protection des Sites Souterrains (CWEPSS) has carried out underground water tracing in ... [more ▼]

In response to the request of the Groundwater Service of the Walloon Region, the Commission Wallonne d'Etude et de Protection des Sites Souterrains (CWEPSS) has carried out underground water tracing in the karstic area of Hastière (Province of Namur, Belgium).The CWEPSS has carried on the task with the cooperation of Geologica SA, Gembloux, for the tracing tests and the collaboration of the Université de Liège for several related parameters (stream gauging, water analyzes, spectrofluorimetry, etc.). At Hastière, several karstic Springs resurge from a large and complex limestone syncline; two water supply stations pump water from this syncline for local use. Fluorescent tracers have been injected into three swallowholes. Three different tracers have been used simultaneously - one in each injection site. They have been traced downstream in 9 potential points of reappearance. In a single one-month field-campaign, the origin of 9 streams has been questioned. Despite the low-water levels during this period, some underground streams have covered more than 3,5 km in 8 days. This shows how important is to permanently watch water supplies in karstic areas. The water intake of the Municipality at Anthée proved to be clean, unpolluted. The authors could define the watch-zone and delineate a prioritary watch sub-zone in the geological formation supplying directly the intake. A private camping intake appeared to be supplied by a sinkhole collecting water from a water purifying station and by another sinking stream swallowing sewage water, hence a high pollution and an important sanitary problem. These findings, among others, show how us « the water tracing technique is in detecting sources and in defining watch and protection zones. [less ▲]

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See detailLa cartographie des contraintes karstiques en Région wallonne (Belgique)
Ek, Camille ULg; Michel, Raymond; Jaspar, Annick

in Bulletin de la Société Géographique de Liège (1999), 36

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See detailTracing techniques as a contribution to karstology : past experiences, new directions.
Meus, Philippe; Ek, Camille ULg

in Andrea, B. (Ed.) Contribución del Estudio de las Cavidades kársticas al Conocimiento geológico (1999)

During a long period, tracer tests aimed exclusively to define water catchment areas in karst basins. Recent developments in the methodology and in the technique itself have largely increased the ... [more ▼]

During a long period, tracer tests aimed exclusively to define water catchment areas in karst basins. Recent developments in the methodology and in the technique itself have largely increased the potentialities of understanding karst flow mechanisms : use of boreholes as injection or measuring points, progress in tracer selection and detection, introduction of continuous monitoring... This paper emphasizes the parallelism between the evolution of the tracing technique and the knowledge of karst. [less ▲]

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See detailLes Phénomènes karstiques: notes de cours
Ek, Camille ULg

Learning material (1998)

1.- Facteurs et processus. Les processus de la dissolution. Facteurs climatiques et météorologiques. Les parts respectives de la dissolution et de l'érosion mécanique. 2.- Formes et dépôts. Les formes ... [more ▼]

1.- Facteurs et processus. Les processus de la dissolution. Facteurs climatiques et météorologiques. Les parts respectives de la dissolution et de l'érosion mécanique. 2.- Formes et dépôts. Les formes karstiques. Les variantes climatiques. Les dépôts en milieu karstique. 3.- Conclusions. [less ▲]

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See detailThe dynamics of the karstic features of Sprimont (Belgium) and its consequences on the land-use planning. Preliminary note.
Ek, Camille ULg; Michel, Raymond; Mousny et al

in Proceedings of tne 12th International Congress of Speleology (1997)

The Department of Physical Geography of the University of Liège (Belgium) was in charge of updating the physical factors of the regional land management map for Sprimont, a karstic municipality of Belgium ... [more ▼]

The Department of Physical Geography of the University of Liège (Belgium) was in charge of updating the physical factors of the regional land management map for Sprimont, a karstic municipality of Belgium. The influence of floods, karst processes, landslides, and other physical factors were evaluated. The karst features and karst-related events have been mapped three times with accuracy in this area during the last century (in 1898, 1971 and 1996). The data provided the basis for a study of the rates and dynamics of the karst processes and permitted the forecasting of hazards on a secular basis. A map of karstic areas, karst features and karst dynamics was prepared. Some systematic trends of the evolution of karst features were noted. A map of risks and land-use constraints was derived from the first map and from the observed trends. Rules were induced from these data and were proposed to control building and other activities in clearly defined areas. [less ▲]

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See detailVariations saisonnières du CO2 de l'air de deux grottes du Jura méridional: La Balme et Cerdon. Comparaison avec d'autres grottes françaises
Sbai, Abdelkader; Ek, Camille ULg; Renault, Philippe

in Annales de la Société Géologique de Belgique (1996), 119

Seasonal measurements of carbon dioxide were made over a period of one year in two caves from southern Jura: the caves of La Balme and of Cerdon. Carbon dioxide contents range from 300 to 15,500 ppm ... [more ▼]

Seasonal measurements of carbon dioxide were made over a period of one year in two caves from southern Jura: the caves of La Balme and of Cerdon. Carbon dioxide contents range from 300 to 15,500 ppm; these low values are correlated with the circulation of the air in the two caves and with the origin of the carbon dioxide. The values found in these caves are then compared with those measured by researchers in other French caves. [less ▲]

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See detailGrottes et rivières des régions calcaires
Ek, Camille ULg

in Demoulin, Alain (Ed.) L'Ardenne, Essai de Géographie physique. Hommage à A. Pissart (1995)

Location of soluble rocks and karstic areas. Morphology of closed depressions. Valleys of limestone regions; dry valleys; blind valleys. Caves. Present-day processes.

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See detailLes roches karstifiables de la Province de Hainaut
Ek, Camille ULg

in De Broyer, Claude (Ed.) Atlas du Karst wallon, Province de Hainaut (1995)

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See detailLes calcaires de Wallonie
Ek, Camille ULg

in Atlas du karst wallon : Province de Namur (1992)

Inventory and description of karstic features of Namur Province

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See detailLa nouvelle grotte de Dinant
Ek, Camille ULg

Book published by Lesire (1990)

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See detailMorphology. Mapping the genesis of the Flying Dragon
Ek, Camille ULg

in Masschelein, J.; Zhang, Shouyue (Eds.) Teng Long Dong, the longest cave of China (1990)

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See detailDes traces de glace de ségrégation dans la grotte de Remouchamps (Belgique) : conséquences en ce qui concerne la sédimentation et la paléoclimatologie
Pissart, Albert ULg; Van Vliet-Lanoë, Brigitte; Ek, Camille ULg et al

in Annales de la Société Géologique de Belgique (1988), 111

In countries with a modern temperate climate, the extent of former permafrost is generally estimated from the observation of ice wedge casts, remnants of pingos and palsas, and periglacial involutions ... [more ▼]

In countries with a modern temperate climate, the extent of former permafrost is generally estimated from the observation of ice wedge casts, remnants of pingos and palsas, and periglacial involutions. These features give no indication at all about the depth of permafrost and are ineffective in identifying the limits of former permafrost. A new tool for this research may be found in caves. We already know that speleothems did not grow -- or grew little — during the colder periods of the last glaciation, probably because of the impervious nature of the frozen ground. The discovery, in the Remouchamps Cave, of the marks of segregation ice in loose fills proves that the temperature did fall below 0°C. Only one cycle of freeze/thaw would have been sufficient to create these marks wich have been preserved because there was indeed little biological activity in this environment. The temperature in such caves is generally very close to the mean annual temperature outside the caves. This evidence will thus be useful for tracing the southern limit of the permafrost in Europe. When the permafrost thawed, the melting of the ice caused mass movements in the cave sediments. The ice had blocked some passages and water levels rose to abnormally high levels, depositing sediments at these levels. [less ▲]

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See detailLes sédiments détritiques des grottes : aperçu synthétique
Ek, Camille ULg; Quinif, Yves

in Annales de la Société géologique de Belgique (1988, September), 111

Clastic sediments in caves may be autochthonous or allochthonous. An overview of scientific works from 1966 to 1986 shows current trends. Energetic balance approach is promising.

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See detailLes concrétions carbonatées des grottes : aperçu synthétique
Gewelt, Michel; Ek, Camille ULg

in Annales de la Société Géologique de Belgique (1988), 111

A synthetic overview of the scientific work on calcium carbonate cave deposits (dripstones and flowstones) over the last twenty years is carried out. More particularly, recent studies on speleothems ... [more ▼]

A synthetic overview of the scientific work on calcium carbonate cave deposits (dripstones and flowstones) over the last twenty years is carried out. More particularly, recent studies on speleothems composition, growth, age and paleoclimatic environment are examined. Main new results are in relation with the development of isotopic and radiometric dating methods which together with other research fields like palynology and tephrostratigraphy make speleothem a first choice material for the study of Late and Upper Quaternary. Beside geomorphological contributions — including Belgian results on maximum rates of valleys entrenchment and deepening — increasing number of dates allow for statistical speleothem repartition studies which could be related with paleoclimates. Two new frequency curves of U-series ages data of speleothems are presented. [less ▲]

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See detailSédimentologie de quelques loess de la grotte Walou à Trooz, Belgique
Chen, Zhiqing; Ek, Camille ULg; Lacroix, Daniel ULg

in Bulletin des Chercheurs de la Wallonie (1988), 28

Two silty sediments are present in Walou Cave. One includes few carbonates and is poorly sorted. The four other ones contains more carbonates, and are better sorted. They have different heavy minerals ... [more ▼]

Two silty sediments are present in Walou Cave. One includes few carbonates and is poorly sorted. The four other ones contains more carbonates, and are better sorted. They have different heavy minerals. The first sample is not a true loess; the other ones are reworked loesses. [less ▲]

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See detailThe significance of CO2 in the dissolution of limestone
Ek, Camille ULg

in Bulletin de la Société Belge d'Etudes Géographiques = Tijdschrift van de Belgische Vereniging voor Aardrijkskundige Studies (1988), 57(1), 110-112

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See detailCarbon dioxide of the air of shallow caves in mountainous areas
Ek, Camille ULg

in International Symposium on the Problems of Karst Study in Mountainous Countries (1987)

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See detailLes remplissages des grottes: concrétions et dépôts détritiques. Aperçu synthétique
Ek, Camille ULg

in Jornadas sobre el Karst en Euskadi, Communicaciones (1986)

Synthetic overview of the twenty last years researches (1965-1985). Current trends. A new approach to the study of cave fills is based on the notion of energetic balance.

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See detailCarbon dioxide in cave atmospheres: new results in Belgium and comparison with some other countries
Ek, Camille ULg; Gewelt, Michel

in Earth Surface Processes & Landforms (1985), 10

More than 600 measurements of carbon dioxide in cave air in Belgium lead to the conclusion that the main factors of its distribution are: (1) a flow originating from the biomass and diffusing in the soil ... [more ▼]

More than 600 measurements of carbon dioxide in cave air in Belgium lead to the conclusion that the main factors of its distribution are: (1) a flow originating from the biomass and diffusing in the soil and the voids of bedrock; (2) a trend to go down by density; (3) in some caves, draughts caused, for instance, by a swift underground stream. Results in Belgium are compared to other countries. l'usage d'un masque absorbant le CO2Special attention is paid to human contamination and the use of a CO2-absorbing mask in defined situations is stressed. [less ▲]

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