Atlantic Ocean ; Bay of Biscay ; Europe ; France ; Gironde Estuary ; Gironde France ; North Atlantic ; Northeast Atlantic ; U-234 ; U-238 ; U-238/U-234 ; Western Europe ; colloidalmaterials ; dissolved materials ; estuarine environment ; estuarine
aux processus de coagulation du matériel colloïdal d'origine fluviale à l'interface eau douce-eau salée, comme cela a été rapporté pour d'autres estuaires où un comportement non conservatif a également été observé.
coatings and clay infillings indicating translocation of colloidal clay and iron oxides from overlying horizons. In addition, bridges between coarse grains of the soil material occur. It is highlighted that swelling clays are responsible for reversible
composition of bridges linking coarse soil material. Quantitative X-ray diffraction shows that the studied fragipan horizon contains high concentration of swelling clay minerals. Soil material from the fragipan horizon exhibits numerous clay and iron-clay
under moderately humid climate conditions. The abundance of clay coatings and clay infillings as well as iron–clay cutans within the studied fragipan indicates that the formation of the pan is related to the translocation of colloids (clay minerals
) is responsible for the subsequent degradation of the pan due to wetting and drying, leading to the swelling and shrinking of soil material. Formation and development of bleached tongues are connected with the infiltrating water by vertical cracks.
Geography instructional materials for standards-based education
Educational programme ; Professional training ; Teaching material ; Teaching of geography ; United States of America
Description of three development projects on geography instructional materials (GIGI, ARGUS and GEOLinks) that support the new geography standards now much discussed in the USA. - (DWG)
Morphological characteristics of gully networks and their relationship to host materials, Baringo District, Kenya in Soil erosion and host materials in Africa.
This paper looks at the morphological characteristics of gully networks developed within three contrasting host materials (one of weathered bedrock, the other two are alluvial deposits) in the Baringo District of Kenya.
Mechanism for the instability of slopes composed of granular materials
The mechanism of instability of slopes composed of granular materials was examined through a tilting-box experiment using an assembly of aluminium rods and direct shear tests. Avalanching of granular materials is triggered by rotation of rods
at the slope surface. The force inducing the rotation was caused by the weight of the particles transmitted through contact points. Therefore, the mechanism of avalanching of granular materials was not comparable to the shear mechanism that has been considered
to be responsible for the instability of slopes made of granular materials.
Translation and development theory in geographic education : a model for the genesis and production of geography instructional materials in a competitive funded grant environment
Development ; Pedagogy ; Primary education ; Secondary education ; Teaching material ; Teaching of geography
Pedagogical essay on the process involved in the production of materials for use in geography classes at primary and secondary levels. - (DWG)
Educational programme ; Geographical association ; School curriculum ; Teaching material ; Teaching of geography ; United States of America
Information on the GIGI and ARGUS projects, the American Geographical society Around the World Program, Geolinks and the Key to the National Geography Standards. These source materials are meant to benefit classroom teachers of geography in the USA
A. considers how we obtain and use visual materials and how they structure our narratives. She notes that the collection of visual materials is often difficult and uncontextualized with notes or other written information. Visual materials used
by historical geographers are usually not interpreted for their political representation. Finally, she urges us to consider how the visual material might reflect underlying precepts of colonialism, masculanism, and racism. - (SLD)
On the basis of exploratory soil surveys and joint field work by Dutch and Vietnamese soil scientists during February 1984 and September 1985, the different kinds of sulfidic materials in the western Mekong delta are described and their distribution
is presented in the form of a generalized map. Two main kinds of sulfidic materials have been recognized.
The characteristics of, and the sources of the soil materials for, pottery groups manufactured in 3 ancient settlements of early Roman Galilee were studied by micromorphological techniques. The micromorphological comparison of the pottery groups
and soil materials shows that 2 main factors influenced the raw-material procurement strategies of the potters of these settlements : the proximity of the soil material to the potters' settlement, and the suitability of the soil material for pottery