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Résultats de la recherche (22 résultats)

Heterogeneity, correlatives, and proposed stratigraphic nomenclature of Hayes tephra set H, Alaska

Heterogeneity, correlatives, and proposed stratigraphic nomenclature of Hayes tephra set H, Alaska
Alaska ; Geochemistry ; Stratigraphic correlation ; Stratigraphy ; Tephrochronology ; Terminology ; Volcanic ash ; Volcanism
1994

Mineralogy and stratigraphy of three deep lateritic profiles of the Jos plateau (Central Nigeria)

The objectives of this study were to investigate and explain the characteristics of selected profiles, to determine their stratigraphic position and to gain insight into the paleoenvironmental conditions of their formation. On the basis
of mineralogical, paleontological, sedimentological and absolute K/Ar age of basalts, the profiles were placed into the transition from Paleogene to Neogene and stratigraphic correlation was suggested.
1994

Large mid-Holocene and late Pleistocene earthquakes on the Oquirrh fault zone, Utah

This study included interpretation of aerial photographs, detailed geologic mapping of surficial deposits at trench sites, profiling fault scarps, excavating and mapping trenches at two sites, and radiocarbon dating key stratigraphic units
. The results emphasize the importance of integrating stratigraphic and geomorphic information in fault investigations for earthquake hazard evaluations.
1994

Correlation of Late Pleistocene glaciolacustrine and marine deposits by means of geomagnetic secular variation, with examples from northern New York and southern Ontario

Glaciolacustrine ; Marine sediment ; New York State ; Ontario ; Palaeogeography ; Palaeomagnetism ; Pleistocene ; Quaternary ; Stratigraphic correlation ; United States of America ; Varves
This paper provides an example of an approach to stratigraphic correlation of glacial sequences that combines studies of glacial sediments related to these former ice borders, with analyses of the secular changes recorded in the depositional
1994

Magnetostratigraphy of cave sediments, Wyandotte Ridge, Crawford County, Indiana: towards a regional correlation

Cave ; Geochronology ; Indiana ; Kentucky ; Palaeomagnetism ; Polarization ; Stratigraphic correlation ; Stratigraphy ; United States
1994

Holocene palaeoenvironmental record preserved in a paraglacial alluvial fan, Sunwapta Pass, Jasper National Park, Alberta, Canada

This paper examines the stratigraphic record preserved in the Icefield Fan in Sunwapta Pass, Alberta. The paper focuses on the sequence of deposits present at this location and the pedogenic response to the radical changes in parent materials
1994

Stratigraphie et aminochronologie des formations quaternaires de la vallée moyenne du Souss, Maroc

Aminostratigraphy ; Climatic variation ; Mineralogy ; Morocco ; Piedmont ; Quaternary ; Sedimentology ; Stratigraphic correlation ; Stratigraphy
1994

Loess accumulation and soil formation in central Kansas, United Sates, during the past 400 000 years

The AA. present here the stratigraphical, chemical, physical and mineralogical records from the loess deposits of central Kansas. The records show a strong correlation with the Louchuan record and the oxygen isotope curve, indicating continuous
1994

Floodplain sediments on the divide between Huang He and Chang Jiang, Gansu province, NW China

Results and discussion of a stratigraphic survey made of a 21-m-profile of floodplain sediments on the watershed between the Chang Jiang (Yangtze River) and Huang He (Yellow River) at 2500 m asl.: distribution of the floodplain deposits
1994

The Simrishamn diamicton, a glacioaquatic sediment in southeastern Skåne, Sweden

Sedimentological investigations of the deposits show that the unit, the Simrishamn diamicton, is an in-situ glacioaquatic sediment. The aim of this study was to find out the origin and stratigraphic position of the unit as one part of a model
1994

Quantitative refinement of calibrated 14C distributions

A new method is presented for using known ordering or other relationships between 14C samples to reduce 14C dating uncertainty. The order of sample formation is often known from,stratigraphic superposition, dendrochronology, or cross-cutting field
1994

Holocene paleoecology of an estuary on Santa Rosa Island, California

The middle to late Holocene history and early Anglo-European settlement impacts on Santa Rosa Island, California, were studied through the analysis of sediments in a small estuarine marsh. A 5.4-m-long sediment core produced a stratigraphic
1994

Aminostratigraphic correlation and geochronology of two Quaternary loess localities, central Mississippi Valley

of these data to existing Quaternary stratigraphic frameworks in the northern and southern Mississippi Valley.
1994

Evidence for a large earthquake and tsunami 100-400 years ago on western Vancouver Island, British Columbia

New stratigraphic evidence and radiocarbon ages, presented in this paper, show that the zone of subsidence associated with earthquakes in the Cascadia subduction zone may extend north to central Vancouver Island. The evidence is in accord
1994

Extent and timing of the last glacial maximum in Southwestern Alaska

The AA. report here on stratigraphic sections relevant to the timing of the last glacial maximum (LGM) in southwestern Alaska, the region between Cook Inlet and Unimak Island, including the Kodiak archipelago. This work has concentrated
1994

Stratigraphy vs. pedogenesis; problems of their correlation within coastal sedimentary facies

Australia ; Dating ; Geochronology ; New South Wales ; Palaeo-environment ; Pedogenesis ; Podsol ; Quaternary ; Stratigraphic correlation ; Thermoluminescence
1994

Episodic late Quaternary palaeogully erosion in northern KwaZulu-Natal, South Africa

sites of stratigraphic, geochronological and palaeoenvironmental importance in the region. Discussion of the results.
1994

New Zealand tephro-chronology as a tool in geomorphic history of the c. 140 ka Mamaku Ignimbrite Plateau and in relating oxygen isotope stages

Climatic variation ; Isotope analysis ; Loess ; New Zealand ; North Island ; Oxygen ; Palaeosol ; Stratigraphic correlation ; Stratigraphy ; Tephrochronology ; Vegetation ; Volcanism
1994

Stagnant ice features in the eastern Baltic

in unusual stratigraphic positions. They exhibit both horizontal and vertical displacement.
1994

Palynologie et paléoenvironnements des épisodes du Sable de Lotbinière et des varves de Deschaillons (Pléistocène supérieur) de la vallée du Saint-Laurent

Canada ; Drainage ; Palaeo-environment ; Palynology ; Pleistocene ; Pollen diagram ; Quaternary ; Saint-Laurent ; Stratigraphic correlation ; Varves ; Watershed
1994