نتایج جستجو برای: geochemical data

تعداد نتایج: 2418944  

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 1979
I Thornton J S Webb

Before the 1960s, comparisons between the distribution of trace elements in the environment and health in the United Kingdom were primarily confined to ad hoc studies in areas associated with particular agricultural disorders or with unusual human mortality or morbidity records. More recently, increasing interest in the importance of trace elements in crop and animal production and in the hazar...

2014
E.M. da Fonseca J.A. Baptista Neto J.J. McAlister B.J. Smith M.A.C. Crapez

Processes involving heavy metals and other contaminants continue to present unsolved environmental questions. To advance the understanding of geochemical processes that involve the bioavailability of contaminants, cores where collected in the Rodrigo de Freitas lagoon, and analyzed for bacterial activity and metal concentrations. Results would suggest an extremely reducing environment where org...

2017
Alyse K Hawley Mónica Torres-Beltrán Elena Zaikova David A Walsh Andreas Mueller Melanie Scofield Sam Kheirandish Chris Payne Larysa Pakhomova Maya Bhatia Olena Shevchuk Esther A Gies Diane Fairley Stephanie A Malfatti Angela D Norbeck Heather M Brewer Ljiljana Pasa-Tolic Tijana Glavina Del Rio Curtis A Suttle Susannah Tringe Steven J Hallam

Marine oxygen minimum zones (OMZs) are widespread regions of the ocean that are currently expanding due to global warming. While inhospitable to most metazoans, OMZs are hotspots for microbial mediated biogeochemical cycling of carbon, nitrogen and sulphur, contributing disproportionately to marine nitrogen loss and climate active trace gas production. Our current understanding of microbial com...

2016
Pilar Madrigal Esteban Gazel Kennet E. Flores Michael Bizimis Brian Jicha

Large igneous provinces, as the surface expression of deep mantle processes, play a key role in the evolution of the planet. Here we analyse the geochemical record and timing of the Pacific Ocean Large Igneous Provinces and preserved accreted terranes to reconstruct the history of pulses of mantle plume upwellings and their relation with a deep-rooted source like the Pacific large low-shear vel...

Journal: :int. journal of mining & geo-engineering 2014
majid keykha hoseinpoor ahmad aryafar

the closed nature of geochemical data has been proven in many studies. compositional data have special properties that mean that standard statistical methods cannot be used to analyse them. these data imply a particular geometry called aitchison geometry in the simplex space. for analysis, the dataset must first be opened by the various transformations provided. one of the most popular of the a...

2001
Qiuming CHENG

Local structural property of an image is often considered in image enhancement with various high/low pass filters. Spatial association indexes (autocorrelation, covariance, and variogram) have been commonly used to characterize the local structure of surfaces for data interpolation in kriging. Singularity is another index measuring the scaling invariant property of measures from a multifractal ...

2008
M. J. BAKER A. J. CRAWFORD R.G.A. BAKER B. J. WOOD M. REHKÄMPER M. SCHÖNBÄCHLER S. G. NIELSEN

Palaeoproterozoic sedimentary basins of north-eastern and central-eastern Australia are host to large amounts of variably deformed and metamorphosed Fe-rich tholeiitic rocks. Emplacement and/or extrusion of the mafic rocks occurred during one or more episodes of crustal thinning relating to a period of regional extension and sedimentation across Palaeoproterozoic northeastern Australia (ca. 173...

2010
William C. Clyde Suyin Ting Kathryn E. Snell Gabriel J. Bowen Yongsheng Tong Paul L. Koch Qian Li Yuanqing Wang

The Nanxiong Basin (Guangdong Province, China) preserves the most complete Asian stratigraphic record of the Cretaceous-Paleogene (K/Pg) boundary extinction and the subsequent Paleocene mammalian radiation. Despite extensive study, the precise placement of the K/Pg boundary in the Nanxiong Basin sequence has been controversial, and the timing of subsequent mammalian turnover is poorly constrain...

Journal: :The Science of the total environment 2002
T M Mighall P W Abrahams J P Grattan D Hayes S Timberlake S Forsyth

This paper presents geochemical data from a blanket peat located close to a Bronze Age copper mine on the northern slopes of the Ystwyth valley, Ceredigion, mid-Wales, UK. The research objective was to explore the possibility that the peat contained a geochemical record of the pollution generateD by mining activity. Four peat monoliths were extracted from the blanket peat to reconstruct the pol...

2017
David C. Gosselin Edwin Harvey Carol D. Frost

The Great Plains (Dakota) aquifer system is one of the most extensive in North America, extending from the Arctic Circle to New Mexico, and underlies approximately 94% of Nebraska. In Nebraska, we do not have the physical ground water monitoring data at the scale that is necessary to manage ground water flow systems. However, first-order management strategies for this regional aquifer can be de...

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