Now showing items 31-40 of 307
Neogene history of the south Pacific tradewinds: Evidence for hemispherical asymmetry of atmospheric circulation
(Elsevier, 1986-05-30)
Eolian dust grains extracted from southeast Pacific pelagic sediments provide a Neogene record of southern hemisphere atmospheric processes. The mass accumulation rate of dust has been low and generally constant at 1-4 ...
Sediment analysis of a prehistoric rockshelter: The Abri Pataud
(Elsevier, 1975-03)
Rockshelter and cave-mouth deposits accumulate in specialized niches through the breakdown of the enclosing bedrock, the addition of windblown and fluvial sediment and, in the case of prehistoric sites, human habitation ...
Chemistry and decomposition of litter from Populus tremuloides Michaux grown at elevated atmospheric CO 2 and varying N availability
(Blackwell Science Ltd, 2001-01)
It has been hypothesized that greater production of total nonstructural carbohydrates (TNC) in foliage grown under elevated atmospheric carbon dioxide (CO 2 ) will result in higher concentrations of defensive compounds in ...
Spatial distribution and seasonal variation in 18 O/ 16 O of modern precipitation and river water across the conterminous USA
(John Wiley & Sons, Ltd., 2005-12-30)
We report a quantitative analysis of regional differences in the the oxygen isotope composition of river water and precipitation across the USA because data are now available to undertake a more geographically and temporally ...
Effects of fuel and forest conservation on future levels of atmospheric carbon dioxide
(Elsevier, 1992-03)
We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a ...
Paleomagnetism of the Late Archean Nyanzian System, western Kenya
(Elsevier, 1994-10)
The Nyanzian System lavas of western Kenya are believed to be the oldest rocks of the Tanzanian Craton. Intrusive age relationships suggest an age [ges]2850 Ma although direct attempts at dating the Nyanzian have produced ...
The mineralogy and petrology of manganese-rich rocks from St. Marcel, Piedmont, Italy
(Springer-Verlag, 1978-10)
Manganese-rich metamorphic rocks containing violan from St. Marcel, Piedmont, Italy formed under blueschist facies conditions, yielding an unusual suite of minerals including omphacite-albite-quartz, braunite, microcline, ...
Mineral inclusions in pyrope crystals from Garnet Ridge, Arizona, USA: implications for processes in the upper mantle
(Springer-Verlag; Springer-Verlag Berlin Heidelberg, 1999-05)
Mineral inclusions in pyrope crystals from Garnet Ridge in the Navajo Volcanic Field on the Colorado Plateau are investigated in this study with emphasis on the oxide minerals. Each pyrope crystal is roughly uniform in ...