Paleosols and their environmental significance during Holocene in Daqingshan Mountain region of inner Mongolia, North China
Studies on the paleosol and the environmental changes during the Holocene in the Daquingshan Mountain were carried out based on the analyses of strata section structure, morphological properties, 14C data, physico-chemical characteristics and soil
micromorphology. The paleosol developed in five periods and it is believed that there probably experienced five climatic changes with cold-arid and warm-humid climate alternating during the Holocene.
Palynologic and geomorphic evidence for environmental change during the Pleistocene-Holocene transition at Point Reyes Peninsula, central coastal California
The AA. describe the pollen and stratigraphic records of three sites on the Point Reyes. These sites provide a well constrained chronology for the changes in both vegetation and geomorphic processes that occurred during the Pleistocene-Holocene
transition. The occurence of debris flows accompanying major aggradation from 12 000 to 10 000 B.P. suggests more intense winter storms during this period.
L'impact des interventions publiques sur les trajectoires des chômeurs de longue durée
A partir des résultats d'une enquête récente auprès d'un échantillon représentatif de 17 000 chômeurs de longue durée du Bassin minier, l'A. a éclairé le rôle joué par les dispositifs institutionnels de formation ou d'emplois intermédiaires, en
étudiant leur impact sur les trajectoires des chômeurs de longue durée. - (AG)
The stratigraphical record and the morphological correlation to the Nahe terraces show that the latest glacis development took place during the Würm glacial and another during the Riss glacial. By analogy it was concluded that the older, higher
glacis remnants were formed during the earlier Pleistocene glacials. The western margin of the Rhine Hessian, Plateau provides, therefore, evidence that glacis and, in a wider sense, pediments did form during the Pleistocene glacials.
Frequency of rare weather events during periods of extreme climate
This paper only deals with two types of extremes, namely low minimum temperatures during the growing season and, to some extent, extreme areal precipitation during 24 hours. The only parameter used to characterize the climate is the average
Elevational shifts of Coleogyne ramossissima in the Mojjave Desert during the Little Ice Age
In this paper, the AA. add to the knowledge of vegetation changes in the Mojave desert during the Little Ice Age through study of fossil woodrat middens located in the eastern part of the desert where substantially greater amounts of precipitation
Climate and sea level during oxygen isotope stage 7b : on-land evidence from New Zealand
Pollen analysis of sediment deposited during stage 7b indicates climate at the time was up to 3oC cooler than present. The climate and sea-level evidence from Landguard Bluff are consistent with oxygen isotopic evidence from deep-sea cores
indicating a marked cooling during stage 7, which is closely associated with a summer radiation minimum centered at about 230,000 yr ago in the Northern Hemisphere.
Effects of rainfall intensity and slope gradient on the dynamics of interrill erosion during soil surface sealing
The dynamics of interrill erosion during seal formation is studied under different simulated rainfall and slope conditions. Soil erodibility during seal formation is evaluated using 2 empirical multiplication-of-factors type models. It seems
Estimation des ressources énergétiques solaires à partir de la durée d'ensoleillement
Durée ; Energie ; Energie solaire ; Ensoleillement ; Estimation ; Géographie physique ; Irradiation ; Ressource
Il y a des relations évidentes, mais pas de parallélisme rigoureux entre la durée d'insolation et l'irradiation (ou énergie totale reçue par unité de surface dans un intervalle de temps donné). Cette dernière est la somme des effets des périodes
Controls on englacial sediment deposition during the November 1996 Jökulhlaup, Skeidarárjökull, Iceland
This paper presents sedimentary evidence for rapid englacial debris entrainment during a recent jökulhlaup, which provides insight into processes of debris entrainment and post-flood landform genesis. This paper aims to : identify and explain
controls on the deposition of englacial flood sediments in relation to known supraglacial outlets; and present a qualitative model for englacial sediment deposition during jökulhlaups.
Paleoecological and climatic changes of the Upper Lerma Basin, Central Mexico during the Holocene
At present, the lake has changed into marshland and is an ideal study site to obtain information for palaeoecological reconstructions because of the presence of different temperate forest types, which have changed in composition during
the Quaternary. The aim of this paper is to document the changes in floristic composition during the Holocene and to relate them to climate changes.
Clustered streamlined forms in Athabasca Valles, Mars : evidence for sediment deposition during floodwater ponding
A unique clustering of layered streamlined forms in Athabasca Valles is hypothesized to reflect a significant hydraulic event. The forms, interpreted as sedimentary, are attributed to extensive sediment deposition during ponding
and then streamlining of this sediment behind flow obstacles during ponded water outflow. These streamlined forms are analogous to those found in depositional basins and other loci of ponding in terrestrial catastrophic flood landscapes. Likewise, the streamlined forms
KARAPINAR, EREGLI VE AKSARAY ARASINDA KALAN MINTAKADA UST-PLIOSEN-KUATERNER VOLKANIZMASI VOLCANIC ACTIVITY AMONG KARAPINAR, EREGLI AND AKSARAY DURING UPPER PLIOCENE-QUATERNARY
Fluvial action and valley development in the central and southern Black Forest during the Late Quaternary in Landforms and landform evolution in West Germany.