نتایج جستجو برای: geochemical data

تعداد نتایج: 2418944  

2000
Clemens Reimann Peter Filzmoser Robert G. Garrett

A large regional geochemical data set of C-horizon podzol samples from a 188,000 km area in the European Arctic, analysed for more than 50 elements, was used to test the influence of different variants of factor analysis on the results extracted. Due to the nature of regional geochemical data (neither normal nor log-normal, strongly skewed, often multimodal data distributions), the simplest met...

Journal: :زمین شناسی اقتصادی 0
محمد علی رجب زاده سهیلا اسماعیلی

jian cu deposit is hosted by surian volcano-sedimentary complex of permo-triassic age on the eastern edge of the sanandaj-sirjan metamorphic zone at a distance of 195 km from shiraz, southwestern iran. the complex consists mainly of metabasalt, chlorite-quartz schist, chlorite-muscovite schist, mica schist and graphite schist. pyrite is the most important sulfide and chalcopyrite is the major c...

2006
N. E. Petro C. M. Pieters

Introduction: The early history of the Moon, namely the first ~700 My following its formation, was an era marked by the formation of 43 basins (impact craters >300 km in diameter) [1,2,3]. Basin formation during this period had significant effects on the entire lunar crust; material from depth was excavated and redistributed across the entire surface [4]. The material redistributed by basins ca...

2017
Phoebe A Cohen Justin V Strauss Alan D Rooney Mukul Sharma Nicholas Tosca

Biomineralization marks one of the most significant evolutionary milestones among the Eukarya, but its roots in the fossil record remain obscure. We report crystallographic and geochemical evidence for controlled eukaryotic biomineralization in Neoproterozoic scale microfossils from the Fifteenmile Group of Yukon, Canada. High-resolution transmission electron microscopy reveals that the microfo...

Journal: :Annals of botany 2015
C Haris Saslis-Lagoudakis Xia Hua Elisabeth Bui Camile Moray Lindell Bromham

BACKGROUND AND AIMS Salt tolerance has evolved many times independently in different plant groups. One possible explanation for this pattern is that it builds upon a general suite of stress-tolerance traits. If this is the case, then we might expect a correlation between salt tolerance and other tolerances to different environmental stresses. This association has been hypothesized for salt and ...

Journal: :Environmental science & technology 2006
M W Fields C E Bagwell S L Carroll T Yan X Liu D B Watson P M Jardine C S Criddle T C Hazen J Zhou

Few studies have demonstrated changes in community structure along a contaminant plume in terms of phylogenetic, functional, and geochemical changes, and such studies are essential to understand how a microbial ecosystem responds to perturbations. Clonal libraries of multiple genes (SSU rDNA, nirK, nirS, amoA, pmoA, and dsrAB) were analyzed from groundwater samples (n = 6) that varied in contam...

2006
E. Tréguier R. Gellert

Introduction: Since January 2004, the twin rovers Spirit and Opportunity of the Mars Exploration Rover (MER) mission have been able to investigate their respective landing sites thanks to the Athena Science Payload [1]. This scientific payload includes the Alpha Particle X-ray Spectrometer (APXS) instrument [2], whose role is to determine the elemental composition of martian soils and rocks. Du...

2003
Anders Meibom Don L. Anderson

A fundamental challenge in modern mantle geochemistry is to link geochemical data with geological and geophysical observations. Most of the early geochemical models involved a layered mantle and the concept of geochemical reservoirs. Indeed, the two layer mantle model has been implicit in almost all geochemical literature and the provenance of oceanic island basalt (OIB) and mid-ocean ridge bas...

Journal: :رخساره های رسوبی 0
محمد خانه باد طیبه گل افشانی سید رضا موسوی حرمی اسداله محبوبی

in this study, depositional environment and provenance of sandstones of the surijeh formation (lower cretaceous) in the abgarm section in the kopet-dagh basin are investigated. analysis of sedimentary facies in this section shows that there are two clastic (continental and coastal plain) and two carbonate (coastal plain) facies associations are present. the results of modal analysis and geochem...

2006
R. L. Korotev

We have obtained compositional data by INAA for several poorly characterized lunar-meteorite stones from hot deserts. Most are FLMs (feldspathic lunar meteorites). Our goal is to use compositional data to address whether any of the stones are paired with others that are better characterized. Dar al Gani 996. DaG 996 is a 12-g FLM stone. We analyzed 9 subsamples totaling 234 mg. Our sample had v...

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