...James A. Grant Abstract Gresens' (1967) method of analysis of changes in volume and concentrations during metasomatism have been applied in many studies of hydrothermal alteration. This paper provides a simple method of solution of Gresens' equations, for both volume (or mass) change...

... listwaenites from Tavreh were assessed relative to the least altered serpentinites. To illustrate these changes quantitatively a comparative analysis of three different methods of calculating mass change was undertaken using Grant's isocon analysis, MacLean's equation and Gresens’ equation. Results from...

... for identifying these patterns and for evaluating attendant hydrothermal mineral zonation. Whole-rock geochemical anomalies are evaluated by calculating mass changes associated with hydrothermal alteration, using a modified version of Gresens’ (1967) equation to compare the composition of altered rocks to fresh...

... in Table 3. Actual gains and losses may be evaluated using Gresens' equation for metasomatic changes ( Gresens, 1966 ; Grant, 1986 ). This model allows evaluation of chemical changes based on various assumptions, viz., constant volume, constant mass or constant concentration of one component...

.... , 2018 , Petrography of Snap Lake kimberlite dyke (Northwest Territories, Canada) and its interaction with country rock granitoids : Journal of Petrology , doi: 10.1093/petrology/egy025 . Grant , J.A. , 1986 , The isocon diagram; a simple solution to Gresens’ equation for metasomatic...

... of mobile elements, and establish mass balance equations. The methods of Grant (1986) ; Potdevin & Marquer (1987) and Baumgartner & Olsen (1995) are based on Gresens’ equation ( Gresens, 1967 ) to calculate the change in mass of an element or a chemical component h (Δ C h ) between...

... of alteration zones of the study area fall in hydrothermal alteration field. MASS BALANCE EQUATIONS AND ISOCON DIAGRAMS Gresens I (1967) method of analysis of change in volume and concentration during metasomatism has been applied in many hydrothermal alterations (Elliot-Meadows and Appleyard, 1991; Sketchley...

... calculation and illustration methods based on the equations of Akella (1966) and Gresens (1967) . Among these methods, Grant’s Isocon Analysis Method has been extensively applied due to its simplicity and efficiency ( Grant, 1986 ). This method does not require any manipulation of the original measured...

... solution to Gresen’s equation for metasomatic alteration . Economic Geology 81 , 1976 – 82 . Graetsch , H. , Florke , O. W. & Miehe , G. 1985 . The nature of water in chalcedony and opal-C from Brazilian agate geodes . Physics and Chemistry of Minerals 12 , 300 – 6...

... of the original rock and the gains and losses of material necessary to produce the altered rock ( Grant, 1986 ). The isocon analysis, a graphical approach used to understand the element mobility in a system was developed by Grant (1986) on the basis of Gresens’ equation for metasomatic alteration. According...

... of 1.94 g Al 2 O 3 . The equation of Gresens (1967) can be expressed as follows in our case: F ig . 10. Isocon diagrams ( Grant 1986 ) in which least-altered rhyodacite rocks are compared to altered equivalents within: (a) the central zone; (b) the proximal zone and (c) the distal zone...

... the complete geochemical data set for precursors and reclassified skarns, as described above. The isocon method uses a modified version of Gresens’s (1967) equation for calculating mass balance. Using the Gresens method, the chemical components of a least altered rock (precursor) are plotted against those...

...Figure 7. Normalized Gresen's plots (e.g., Gresen, 1967 ; Potdevin and Marquer, 1987 ) displaying volume-composition relationships. We use an equation of the form ΔXn = Fv(δII/δI)(CnII/CnI) − 1; whereby ΔXn represents the percentage of variation related to the host rock composition, Fv...

... diagram; a simple solution to Gresens’ equation for metasomatic alteration . Economic Geology and the Bulletin of the Society of Economic Geologists , 81 : 1976 – 1982 . Greenwood H.J. 1967 . Wollastonite; stability in H 2 O–CO 2 mixtures and occurrence in a contact-metamorphic aureole...

... (Sigma deposit – Canada) . in “Goldschmidt 2002 – From Stars to Life” , R A. Podosek , ed. 66 . Geochimica et Cosmochimica Acta, Pergamon Press , Davos, Switzerland , A263 . Grant , J. A. ( 1986 ): The isocon diagram – a simple solution to Gresens’ equation for metasomatic...

... methods, which are numerous ( Grant 1986 ; MacLean & Barrett 1993 ; Barrett & MacLean 1994 ), are based upon the equation of mass transfer (Equation 1) ( Gresens 1967 ; Leitch & Lentz 1994 ). At Beattie, Bourdeau (2013) used the Isocon method ( Grant 1986 , 2005 ) to conclude that Au...

...: The first is mass-balance calculations that use chemical analyses of major elements. In addition, for some methods volatile or trace element analyses might be required. Mass-balance methods are based on a mass transfer equation ( Gresens, 1967 ; Leitch and Lentz, 1994 ; Stanley and Madeisky, 1994 ) used...

... ). The isocon method ñ a simple solution to Gresen’s equation for metasomatic alteration . Economic Geology , 81 , 1976 – 1982 . Gresen , R.L. ( 1967 ) Composition-volume relationships of metasomatism . Chemical Geology , 2 , 47 – 55 . Harmer , R.E. and Sharpe , M.R. ( 1985...