Abstract. The aim of this paper is to present a practical and accurate program of correction based on a new mathematical description of q~(pz), which allows a global correction combining atomic number and absorption correction [ZA]. Key words: EPMA, computer program, correction procedure, X-ray depth distribution.Electron probe microanalysis (EPMA) requires several corrections to quantify a specimen. These corrections allow to convert the measured intensity of the characteristic X-ray into elemental concentration. The measured intensity I~ emitted from element A in a homogeneous sample is expressed (in the absence of significant fluorescence effects) by: I~ = cst " C A J o tb e(PZ) " exp(--ZePZ) dpz ,where Ca is the weight fraction of element A, pz is the mass depth in the sample,

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Results from measurements of K-shell ionization cross sections of the elements Cr, Ni and Cu by electron impact with energies in the range 6.5-40 keV are presented. Cross sections were obtained by measuring characteristic x-rays emitted from (1-6 nm thick) films of the studied elements deposited on self-supporting carbon backing films. The procedure yields relative cross sections with uncertainties of the order of 2%. Transformation to absolute units increases the uncertainties to about 10%. Our results are compared with those from other groups and with two calculations based on the first Born approximation, which include corrections for exchange, Coulomb and relativistic effects. A simple empirical formula that accurately describes the energy dependence of the measured cross sections is provided.

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Abstract. During the Neoproterozoic orogeny, the middle crust of the Araçuaí belt underwent widespread partial melting. At the regional scale, this anatectic domain is characterized by a progressive rotation of the flow direction from south to north, suggesting a 3-D deformation of the anatectic middle crust. To better determine whether melt volumes present in the anatectic middle crust of the Araçuaí orogen were large enough to allow a combination of gravity-driven and convergence-driven deformation, we used the titaniumin-quartz (TitaniQ) geothermometer to estimate the crystallization temperatures of quartz grains in the anatectic rocks. When possible, we compared these estimates with thermobarometric estimates from traditional exchange geothermobarometers applied to neighboring migmatitic kinzigites. TitaniQ temperatures range from 750 to 900 • C, suggesting that quartz starts crystallizing at minimum temperatures of ≥ 800 • C. These results, combined with the bulk-rock chemical composition of diatexites, allows the estimation of a minimum of ∼ 30 % melt and a corresponding viscosity of ∼ 10 9 -10 10 Pa s. Such a minimum melt content and low viscosity are in agreement with interconnected melt networks observed in the field. Considering that these characteristics are homogeneous over a wide area, this supports the finding that the strength of the middle crust was severely weakened by extensive partial melting, making it prone to gravitydriven flow and lateral extrusion.

XFILM is a computer program for determining the thickness and composition of thin films on substrates and multilayers by electron probe microanalysis. In this study, we describe the X-ray emission model implemented in the latest version of XFILM and assess its reliability by comparing measured and calculated k-ratios from thin-film samples available in the literature. We present and discuss examples of applications of XFILM that illustrate the capabilities of the program.