منابع مشابه
Elemental geochemistry of sedimentary rocks at Yellowknife Bay, Gale crater, Mars.
Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicate...
متن کاملIsotope Geochemistry
Isotopic analysis can be performed on minerals, rocks, soil, tissue, gases, and liquids – just about anything. In view of the broad possibilities, we will only cover a few generalities here. In most instances, the element to be analyzed must be first isolated and purified before it can undergo isotopic analysis in a mass spectrometer. Purification is necessary to avoid isobaric interferences an...
متن کاملElemental mixing systematics and Sr–Nd isotope geochemistry of mélange formation: Obstacles to identification of fluid sources to arc volcanics
We present major and trace element concentrations in conjunction with Sr–Nd isotope ratios to investigate the geochemical characteristics of mélange formation along the subduction zone slab–mantle interface. Mélange matrix of the Catalina Schist formed within an active subduction zone of the southern California borderland in Cretaceous time. Mélange formed through the synergistic effects of def...
متن کاملSpatial variability of organic matter molecular composition and elemental geochemistry in surface sediments of a small boreal Swedish lake
The composition of sediment organic matter (OM) exerts a strong control on biogeochemical processes in lakes, such as those involved in the fate of carbon, nutrients and trace metals. While between-lake spatial variability of OM quality is increasingly investigated, we explored in this study how the molecular composition of sediment OM varies spatially within a single lake and related this vari...
متن کاملChapter 5 Geochemistry
One hundred and nineteen samples of clay (n = 42), rock and sand temper (n = 7), and pottery (n = 70) from the various drainages in and around the North Carolina Sandhills were analyzed by instrumental neutron activation analysis (NAA) at the University of Missouri Research Reactor Center (MURR). Here we report the analytical methods and describe some of the chemical patterns identified in the ...
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ژورنال
عنوان ژورنال: Science
سال: 2005
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.307.5713.1171d