Geomorphological applications of cosmogenic isotopeanalysis
Bibliography ; Dating ; Erosion rate ; Geochemistry ; Geomorphology ; Isotopeanalysis ; Mass movement ; Weathering
The AA. focus on the geomorphological applications of in situ-produced cosmogenic isotopeanalysis. The past decade has seen a rapid growth in applications of cosmogenic isotopeanalysis to a wide range of geomorphological problems
This paper proposes, as a testable hypothesis, a basin-scale approach for interpreting the abundance of in situ produced cosmogenic isotopes, an approach which considers explicitly both the isotope and sediment flux through a drainage basin
. This model is designed for interpreting isotope abundance in sediment. The AA. suggest that measured isotope abundances may reflect spatially averaged rates of erosion if a basin is in isotopic steady state and if sampled sediments are well mixed.
Isotopic approach to soil carbonate dynamics and implications for paleoclimatic interpretations
Carbon ; Carbonate ; Geochemistry ; Holocene ; Isotopeanalysis ; Nevada ; Oxygen 18 ; Palaeoclimatology ; Semi-arid area ; Soil ; United States
The AA. examine stable and radiogenic isotopes of C and stable isotopes of O in carbonate sampled from gravel coatings and soil matrix in three Holocene soils from a semiarid region in Nevada. By comparing isotopic measurements with modeled stable
isotope profiles and radiocarbon ages, the AA. assess the nature of soil carbonate with respect to its origin (detrital, dust, or pedogenic) and dynamic nature (closed or open to atmospheric CO2) over time.
Monthly precipitation samples were collected at Tsukuba City from 1992 to 2006, and isotope ratios of oxygen and hydrogen were analyzed for all samples. The isotope ratios of monthly precipitation have no remarkable trend in their seasonal change
. The temperature effect on isotopes in precipitation is found durinf cool period. In cases of snowfall, precipitation from Baiu front and autumnal rain front, the isotope ratios in precipitation are relatively lighter than those of other cases.
Groundwater isotopic evidence for paleorecharge in U.S. High Plains aquifers
Aquifer ; Deuterium ; Great Basin ; Groundwater ; Isotopeanalysis ; Oxygen 18 ; Palaeohydrology ; Tritium ; United States of America
This study interprets relative groundwater ages, distinguishes vertical and lateral flow paths, and evaluates paleoclimatic implications of isotopic stratification of groundwater beneath the U.S. High Plains.
This paper discusses the chemical evolution and the recharge elevation of spring water by using major dissolved components and isotopic composition around Asama volcano. In addition the A. will provide the conceptual model of groundwater flow system
The development of biogeography as a science has involved the assimilation of both new concepts and new techniques. Stable isotopes have been used in the study of climatic history, the evolution of the biosphere, the biogechemical cycling
Fractionation mechanism of stable isotope in evaporating water body
China ; Evaporation ; Isotopeanalysis ; Lake ; Moisture ; Simulation ; Temperature ; Tibet ; Water cycle
This study quantificationally analyses the interaction between evaporating water body and atmosphere, and the influences of different factors on the evaporation by probing into the fractionation mechanism of stable isotope as water body is vaporized
The AA. present the preliminary results of measurements of diurnal changes in the isotopic composition of atmospheric CO2 in Kraków. They present four experiments done in different seasons of the year. Results show that the isotope composition
This paper assesses the preservation of biogenic isotopic composition of the collagen fraction of mammal bone and tooth from the uppermost well-defined layer of the cave (numbered 1A) and determines the ecological basis for interspecific differences
in the carbon and nitrogen isotopic compositions of mammals from other late Pleistocene sites in Eurasia.
The AA. examine evidence for climatic change at the Aubrey Clovis site, north-central Texas, over the past 14,000 yr. The primary emphasis of this paper will be on stable isotopic evidence from pedogenic and lacustrine carbonates from the study site
. An indepedently derived alluvial history from the same locality corroborate the isotopic data.
The origin of sulphates : an example of sulphur isotopic applications
Arid area ; Biogeochemical cycle ; Cold area ; Evaporite ; Geochemistry ; Gypsum ; Human impact ; Isotopeanalysis ; Palaeo-environment ; Pollution
This review is concerned with the technique of stable isotopeanalysis (δS 34) as a means of studying the sulphur cycle with particular emphasis on the formation of sulphate evaporites such as gypsum. Gypsum is found in all settings that promote
Environmental isotopes, such as oxygen-18 and deuterium, have been used increasingly to separate stormflow into its event and pre-event components in order to elucidate the sources, pathways and residence times of water in drainage basins
. The hydrological processes that have been invoked to explain the observed isotopic response of streamflow to rainfall and snowmelt inputs in various environments are reviewed. This paper summarizes the environmental isotope hydrograph separation technique
and provides a broad review of the results of isotope hydrograph separations conducted around the world.
Holocene paleohydrology and paleoclimate at treeline, North-Central Russia, inferred from oxygen isotope records in lake sediment cellulose
The AA. use lake-water oxygen-isotope histories, inferred from stratigraphic analysis of cellulose in the fine-grained fraction of lake-sediment cores, to reconstruct Holocene paleohydrology at the boreal treeline near the lower Yenisey and Lena
Rivers of northern Russia. These studies are supplemented by isotopicanalysis of samples of modern meteoric water, including precipitation, groundwater, and ground-ice, which provide insight into the modern isotope hydrology. The isotopic records
Evolution of isotopic composition and concentration of atmospheric CO2 as result of anthropogenic influences
Atmosphere ; Carbon dioxide ; Cracow ; Geochemistry ; Human impact ; Isotopeanalysis ; Poland ; Pollution ; Town
Systematic investigations of the isotopic composition in atmospheric CO2 and its concentration in Cracow urban area have been carried on. Continuous sampling at biweekly intervals was supplemented by series of samples representing four-hour periods
To provide more detail information on the effect of flow rate on strontium isotope ratios, the Sr 87/Sr 86 ratio was measured in streamwater samples taken at low and high flow rates and also in samples taken at four and eight hourly intervals during
The spatial distribution patterns of total organic carbon and total nitrogen show significant correlations with currents of the East China Sea Shelf. The purposes of this paper are to analyze characteristics of stable carbon and nitrogen isotopes
Phytolith and carbon isotope evidence for late Quaternary vegetation and climate change in the Southern Black Hills, South Dakota
C 14 dating ; Carbon ; Climatic variation ; Grassland ; Holocene ; Isotopeanalysis ; Palaeobiogeography ; Quaternary ; South Dakota ; United States of America ; Vegetation
Analyses of phytoliths and carbon isotopes document the rate and nature change in late Quaternary grasslands in the Red Valley of the southern Black Hills. This paper will evaluate the temporal sensitivity and spatial limits of the methods.
Strontium isotope ages of the marine Merced Formation, near San Francisco, California
California ; Foraminifera ; Glacio eustatic change ; Isotopeanalysis ; Pleistocene ; Quaternary ; Sea level ; United States of America
The strontium isotopic compositions of foraminifers were determined to refine the age of coastal sediments of the Merced Formation and to evaluate the relation between transgressive-regressive cycles and Pleistocene glacio-eustatic sea-level
and porewater evolution using sedimentology, stable isotopes, and groundwater chemistry. This study will serve to assist the Walpole Island community in future land-use planning.