deathsoli.blogg.se - Formation xlstat

The user can choose between a p-value computed using on an approximation of the exact distribution of the RV statistic with the Pearson type III approximation (Kazi-Aoual et al., 1995), and a p-value computed usingMonte Carlo resamplings. Two methods to compute the p-value are proposed by XLSTAT. XLSTAT allows testing if the obtained RV coefficient is significantly different from 0 or not.

To choose the k first variables from both matrices and compute the RV coefficient between the two resulting matrices.

To compute the RV coefficient between two matrices, including all variables form both matrices.

The closer to 1 the RV is, the more similar the two matrices W i and W j are. The RV coefficient is a generalization of the squared Pearson correlation coefficient. Where trace(W i,W j) = Σ l,mw i l,mw j l,m is a generalized covariance coefficient between matrices between matrices W i and W j, trace(W i,W i) = Σ l,mw i l,m 2 is a generalized variance of matrix W i and w i l,m is the (l,m) element of matrix W i. The RV coefficient is defined as (Robert and Escoufier, 1976 Schlich, 1996): This tool allows computing the RV coefficient between two matrices of quantitative variables. The Sanaga iron formations are metamorphosed chemical sediments formed by precipitation of iron and silica from a mixture of seawater and hydrothermal fluids with a significant terrigenous input.The RV coefficient depicts the similarity between two matrices of quantitative variables or two configurations resulting from multivariate analysis. The high concentration of Al 2O 3 (average 9.34 wt %) in the oxidized iron formations is partially due to its introduction during recent chemical weathering. From these data it appears that mineralisation at the Sanaga prospect is restricted to the magnetite gneiss. Concentrations of trace elements in the various lithologies are generally very low ( 0.8), and Zr (r > 0.7) LOI with Zr (r > 0.8). Al 2O 3 averages 9.34 wt % and 3.06 wt %, Na 2O averages 0.04 wt % and 0.59 wt %, K 2O averages 0.26 and 0.53 wt %, and P 2O 5 0.07 and 0.05 wt %, respectively, in both oxidized and gneissic formations.

Bulk geochemical analysis of the oxidized and gneissic formations showed that Fe 2O 3 and SiO 2 are the main constituents (averaging 84.40 wt % and 92.54 wt %, respectively), confirming that quartz and iron oxides are the major mineral phases in both the oxidised and gneissic formations. Detailed examination showed that quartz and iron oxides are the main minerals present. The stratigraphic log described revealed from top to bottom two lithological sequences composed of oxidized formations (oxidized cap and oxidized gneiss), and gneissic formations (magnetite gneiss, magnetite amphibolite gneiss and enriched magnetite amphibolite gneiss successions). All data were processed with the aid of XLSTAT. Major elements were analysed using X-ray fluorescence spectrometry after powder digestion following. The rock samples were collected from a single drill core sampled at various depths. The objective of this study is to use geochemical data trends for major and some trace elements to constrain the origin and/or sources of various constituents in the iron-bearing units as well as assess their economic potentials.

The Sanaga prospect in the north of Edea is located in the upper Nyong unit of the Ntem complex in Cameroon. I., Geology Laboratory, Higher Teacher Training College, University of Yaounde I de Yaoundé I, Yaoundé, Cameroun. Geochemical Characterization of a Stratigraphic Log Bearing Iron Ore in the Sanaga Prospect, Upper Nyong Unit of Ntem Complex, Cameroon. 5, 218-228 DOI: 10.12691/jgg-5-5-1 Copyright © 2017 Science and Education Publishing Cite this paper: Ilouga D. 3ġGeology Laboratory, Higher Teacher Training College, University of Yaounde I de Yaoundé I, Yaoundé, CamerounĢOre Processing Laboratory, IRGM, Yaounde, CameroonģDepartment of Earths Sciences, University of Yaounde I, Yaounde, CameroonĤDepartment of Geology, University of Buea, South West Region, Buea, Cameroo Journal of Geosciences and Geomatics.