نتایج جستجو برای: Geochemical Elements Estimation

تعداد نتایج: 545090  

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشکده علوم زمین سازمان زمین شناسی و اکتشافات مع 1390

the neogene intrusion masses in the noudeh-enghelab area located to the north of sabzevar ophiolite have cut the late cretaceous ophiolitic rocks, sedimentary- volcanic and eocene volcanic rocks and have been covered by pliocene and quaternary deposits. the margin is of lava with basalt, phyric andesite-basalt and andesite and the central parts (dome shaped) composed of phyric andesite-trachyan...

Bearing in mind that lack of data is a common problem in the study of porphyry copper mining exploration, our goal was set to identify the hidden patterns within the data and to extend the information to the data-less areas. To do this, the combination of pattern recognition techniques has been used. In this work, multi-layer neural network was used to estimate the concentration of geochemical ...

Due to the existence of a constant sum of constraints, the geochemical data is presented as the compositional data that has a closed number system. A closed number system is a dataset that includes several variables. The summation value of variables is constant, being equal to one. By calculating the correlation coefficient of a closed number system and comparing it with an open number system, ...

Journal: Geopersia 2016

This study aims to recognize effect of Ordinary Kriging (OK) and Inverse Distance Weighted (IDW) estimation methods for separation of geochemical anomalies based on soil samples using Concentration-Area (C-A) fractal model in Irankuh area, central Iran. Variograms and anisotropic ellipsoid were generated for the Pb and Zn distribution. Thresholds values from the C-A log-log plots based on the e...

Journal: Geopersia 2018

The purpose of this study is to determine geochemical anomalies on lithogeochemical data from Ardestan area, Central Iran, using concentration-number (C-N) fractal modeling and staged factor analysis. Staged factor analysis is used to the recognition of genetic correlation and elimination of non-indicator elements in three steps. Factor scores of elements were calculated and geochemical data cl...

Journal: :زمین شناسی اقتصادی 0
وحیده علیپور علی عابدینی

the zonouz kaolin deposit is located ~15 km northeast of marand, east-azarbaidjan province. based on physical features in field investigations, such as color, five distinct kaolin types including (1) white, (2) lemon, (3) gray, (4) brown, and (5) yellow are distinguished in the deposit. field evidence and petrographic studies indicate that the deposit is genetically close to trachy-andesite roc...

2005
Katrin Grünfeld

Geochemical mapping programs carried out by the Geological Survey of Sweden (SGU) have generated large databases containing information on the concentrations of chemical elements in rocks, surface sediments and biogeochemical materials. Regional geochemical data being imprecise, multivariate, spatially auto-correlated and non-normally distributed pose specific problems to the choice of data ana...

Journal: :The Science of the total environment 2005
Clemens Reimann Patrice de Caritat

High element enrichment factors (EFs) are commonly used in the literature to support the hypothesis that a particular suite of elements is of anthropogenic origin. Real-world examples of regional geochemical surveys demonstrate that EFs can be high or low due to a multitude of reasons, of which contamination is but one. This applies to EFs calculated relative to either the crust or some local b...

2015
Lei Dou Tingting Li L. Dou T. T. Li

Soil heavy metal pollution is one of the main environmental problems in Pearl River Delta Economic Zone of China. Based on multi-purpose regional geochemical survey, regional eco-geochemical assessment, local eco-geochemical assessment and comprehensive appraisal, the eco-geochemical survey and assessment in Pearl River Delta Economic Zone of 41,698 km2 were completed. Samples from soils were c...

Journal: :تحقیقات آب و خاک ایران 0
علیرضا راهب دانشگاه تهران احمد حیدری دانشگاه تهران شهلا محمودی دانشگاه تهران

soil genesis and evolution studies are based on well understanding of geochemical processes involved in pedogenic processes and formation of soil. parent materials are main factors controlling soil properties in arid and semiarid regions. in this study, physicochemical and geochemical properties of 6 selected soil profiles developed on basalt rocks along arid (eshtehard), semiarid (qazvin) and ...

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